Post by: awemawson on May 19, 2018, 07:14:19 AM
This Beaver TC 20 CNC lathe was too much to resist - after all it's paint scheme matches my Beaver PartsMaster CNC Mill :lol:
Ex Portsmouth University, the sellers father bought it, had it briefly running, but then unfortunately died - that was five years ago and the machine has sat unused and un-powered for that period. The cosmetics of the outside are excellent, but inside the swarf guards have light rust - it's obviously been turning machinable wax, as there is still some swarf in it, and that would be without coolant, so the guards haven't been kept oily by coolant hence the rust.
The control is a Siemens Sinumerik 820T - having been left powered off the back up battery (last changed 2008!) is obviously dead as a door nail and all the parameters and plc data have been lost.
I went to inspect on Thursday, and although I got 3 phase power on to the machine I could get nothing what so ever out of the controller - no screen display, no leds nowt :scratch: Might be dead simple, might be a nightmare
A bit smaller than the Traub this is an estimated 3 tons and has a 2.75 x 1.98 metre footprint - just need to get it shifted the 80 miles home and I can start playing :ddb: :ddb: :ddb: :ddb:
Post by: awemawson on May 19, 2018, 07:22:47 AM
Fortunately there is a floppy disk in a door pocket that claims to have the machine and plc parameters on it - I do hope so - it may just be blank :bugeye:
Post by: Joules on May 19, 2018, 07:26:44 AM
:lol:
Post by: seadog on May 19, 2018, 07:52:36 AM
Post by: awemawson on May 23, 2018, 12:55:40 AM
The one I've found is off a Beaver CNC lathe and was left behind when the lathe was sold. Vendor can't remember the model number, "but the Chuck was 300 mm". Now the TC 20 has a 250 mm Chuck and as far as I can find out Beaver never made a CNC lathe with a 300 mm Chuck
Chuck size is important as the probe reaches round and past it to touch the selected tool in the turret. The problem is that these probes are assembled from a huge variety of element lengths to suit a particular machine - hopefully if this isn't spot on I can move the programmed measuring point to suit it - I'm hoping he'd forgotten the size of his chuck - I never mentioned Beaver, he named the lathe so hopefully . . . :med:
Darren, my Tractor Shed builder has volunteered to shift the machine the 80 miles to my place, but we are waiting on the seller to fix the steering ram on his forklift so he can load it
Post by: awemawson on May 23, 2018, 08:54:35 AM
The touch probe seller has been in touch (no pun intended!) and confirmed that it was off a TC-20 lathe, and not only that he still has manuals for the Sinumerik controller - so how good is that :clap:
. . . . negotiations are in progress . . . . :ddb:
Post by: awemawson on May 23, 2018, 10:20:26 AM
Turns out that the probe I've found is coming from Gosport - now the lathe was originally at Portsmouth University 13 miles away by road, but by Gosport ferry across Portsmouth Harbour probably less than a mile :bugeye:
Now from my research Beaver were making about 45 TC-20 per year from 1987 to 1992 - or approximately 225 as a total world population - surely there has to be a very high chance that this is the original probe.
. . . how cool would that be . . . suitable question fired off to probe seller regarding his affinity to the Engineering Dept at Portsmouth University :ddb: :ddb:
Post by: Brass_Machine on May 23, 2018, 01:16:32 PM
Nice find! But, are you gearing up to run a production line?
Eric
Post by: awemawson on May 23, 2018, 01:29:01 PM
As you know well, it's the journey that I enjoy rather than the end result :clap:
I just love taking some neglected unloved bit of machinery and putting it right, if only some young slip of a gal would do the same with me and put a smile on my face :lol:
Post by: Brass_Machine on May 23, 2018, 02:06:36 PM
Post by: awemawson on May 24, 2018, 10:29:24 AM
Not only that - he still has manuals and training materials - negotiations ongoing . . . .
Post by: Pete. on May 24, 2018, 12:23:02 PM
Post by: hermetic on May 24, 2018, 01:03:07 PM
Post by: awemawson on May 24, 2018, 03:46:31 PM
. . . . the manuals are mine and being posted tomorrow. He was last machining PTFE on it, and that was 2010 - the swarf from it is still in the machine :clap:
Post by: awemawson on May 30, 2018, 10:57:16 AM
BUT - the probe has arrived along with the bundle of software manuals, as has a second hand 'Peli Case' that I bought to house it. The tip of the probe would originally have had a protective cover, which has gone missing so I 3D printed one this morning, and at the moment the Cetus 3D printer is making me a cap to protect the electrical connector, but that has another three hours to run.
. . . just need the 'pick and pluck' foam block that I have on order for the Peli case and it will be safe.
. . . oh and the lathe would be quite handy too :lol:
Post by: awemawson on May 30, 2018, 01:14:35 PM
The nice chap who sold me the probe has been looking though his files and has emailed me with what appears to be a complete set of back up parameters from this machine for the 820T controller, the PLC, and all the various off set corrections and pitch corrections. He has even included one or two examples of programs.
Funnily enough today I was looking through his programming course notes hand out that he had sent with the probe, and noticed that in the very first example they give they had printed an error - simple positioning to turn a stepped profile - it had the set up bits like metric measurement, absolute positioning etc then went straight into a list of co-ordinates without issuing a G00 or G01 move command, so it could never have worked. I hope they found that on the course :clap:
At last I've found a weight for the machine - 6.25 tons :bugeye: and at vast expense have commissioned a professional machine moving company to collect and deliver using their enormous hi-ab equipped lorry - only problem now is that the seller is proving elusive and not answering phones or texts.
Meanwhile I've been offered another Beaver TC-20, slightly younger but in far worse condition cosmetically for less than it's costing to MOVE mine ! Shame to miss it, as obviously it would be an excellent spares 'Christmas Tree', but again I'd have to move it. Tempting as I have room for it and it has a full set of documentation. I'll try and liberate the documentation at least, or just maybe buy it and strip it on site though the removable chunks are pretty sizable on their own .
. . . any volunteers for a day out in Birmingham helping me pulling a machine apart in a controlled fashion !
It's not quite identical being fitted with a different tool turret and machine control panel but the Sinumerik controller is fundamentally the same. Picture to show it's not as nice as mine :ddb:
Post by: chipenter on May 30, 2018, 01:53:43 PM
Post by: awemawson on May 30, 2018, 02:58:30 PM
Post by: AdeV on May 30, 2018, 05:00:57 PM
...be extremely cautious with that seller.
I bought my first Interact 1 Mk2 machine from him. It was described as being in "good working order", having a TNC151 controller, and - since the photos on eBay showed it outdoors - I specifically asked if it was stored indoors, to which I received an affirmative.
When my man went to pick it up, it was still outside, and soaking wet (it's Birmingham, it rains almost as much there as in Manchester).
The tools, when I got them, were all full of water.
The controller was a TNC150, not the promised TNC151 (ok, I can maybe understand that mistake).
Once I'd given the machine a week in a warm place to dry out, it "mostly" worked. The motor cooling fan was seized (from the rain, probably) and the coolant pump didn't work.
Fortunately, I managed to acquire the machine I still use to this day, for less money, later on; and shifted the less good machine on for what I paid for it (to a chap who was happy to take it at the price even with the faults described).
It's highly unlikely it's costing Bilal anything in warehousing; chances are it's still at it's original owner's place, and he's screaming to get it out of the bl**dy way...
Post by: awemawson on May 31, 2018, 12:58:44 PM
There's good and bad in all of us I suspect :med:
Post by: awemawson on June 12, 2018, 04:46:43 AM
Now this has sent me into a flurry, as previously it was going to be tomorrow and I've committed to transporting an elderly friend to and from the dentist for a check up bang on when it's expected :bang: Oh well I expect it'll sort itself out :scratch:
Have some pictures of my lathe swinging from a large hook !
Post by: awemawson on June 12, 2018, 10:19:18 AM
So we got back to the farm in time to see the lathe swinging again on the hook - a very professional chap on the (remote) control knew just what to do - extending the Hi-Ab as far as the load limiter would allow got it poked so that the Tailstock end was just able to be put on skates, then he shifted the lifting point to the Headstock end and was able to gently ease it into place.
Then a bit of work with some rather nice toe jacks got it off the skates and back on it's levelling feet. All a bit tight but 'workable' (I hope) - it's slightly smaller than the Traub so how the heck I got that in I don't know :scratch:
It's been a bit of an emotional roller coaster getting so far and I feel exhausted, but when I've fed the pigs I'll go back to the workshop and try and get a feel for what I've taken on this time :bugeye:
Post by: awemawson on June 12, 2018, 10:24:12 AM
Of course it would never have moved if Geoff hadn't given a push at the crucial time :lol:
Post by: j1312v on June 12, 2018, 11:25:07 AM
I that the ex-uni lathe or the one in the Midlands?
Post by: awemawson on June 12, 2018, 01:39:25 PM
. . . who's Matt :scratch:
State of play at the moment is that I have it wired to 415 three phase. With an earth connected it's tripping a 100mA RCD - (when I hooked it up on site it had no earth) - symptoms remain as previously, no life or LEDs on the controller.
I'll try and pull the controller out this evening and see what's happening - the way it's mounted is a bit silly as there is no easy way to it's rear other than unscrewing it, and the back up battery is mounted on the rear of the controller. This battery has to be changed with the power on, so not sure how that is supposed to happen - may find out later!
Post by: hermetic on June 12, 2018, 02:09:47 PM
Post by: awemawson on June 12, 2018, 02:28:35 PM
Post by: awemawson on June 12, 2018, 04:29:35 PM
I started by removing all the numerous screws retaining the Operators Panel, and noticing that one corner is broken but all bits there for later gluing. Having pulled the panel forward revealing the expected backs of switches, cables etc I noticed a small wet patch of brown liquid that obviously had come from above. There is only the control above and no way water falling on top of the machine could get to here as it is a solid box. Burst Capacitor or Battery I'm thinking at this point.
OK put the panel back and attack the Controller. Removing all it's screws there is no away it will pull out.
Post by: j1312v on June 12, 2018, 04:37:40 PM
Good luck finding that earthed bit on the machine, one think that helps is to disconnect, clean and reconnect... :dremel:
Post by: awemawson on June 12, 2018, 04:41:13 PM
It was at this point I dropped the torch inside and no way could I get my fingers to it :bang:
However feeling about inside as far as I could reach I discovered some Bakelite knurled headed screw knobs holding the surrounding panel in place. They were far too tight for hand unscrewing, and gripping them with pliers took some major contortions but they all came off in the end allowing me to unscrew the panel, get my hand in further to rescue the torch, and also see that the square holes under the controller were obviously intended to support a temporary shelf to pull the controller onto.
I cut some 3/4" square bar to make two supports for a bit of surplus aluminium plate as a shelf, and reached in and was able to unscrew the retaining bracket
Post by: awemawson on June 12, 2018, 04:47:40 PM
I'm sure the horrors MUST have been caused by a leaking battery, but I cannot at the moment see it, OR it's holder - very strange.
But that's enough for today - I'm wacked
Post by: vtsteam on June 12, 2018, 11:58:51 PM
Post by: awemawson on June 13, 2018, 05:58:19 AM
This mornings objective - get the controller out of the machine and find where the battery is / was.
I went round arbitrarily labelling cables and their associated sockets so that I stand some chance of getting it back as it was , then it was a case of unscrewing socket retainers pulling cables off and withdrawing the controller. Some of the badly corroded fixings on cable shell sheared off not surprisingly.
(many of these pictures are for record purposes so perhaps a bit boring - sorry :scratch:)
Post by: awemawson on June 13, 2018, 06:02:25 AM
But finally all cards were removed from the card cage - quite a bit of electronics here :bugeye:
Post by: awemawson on June 13, 2018, 06:15:21 AM
It holds a plug in sub-module with the culprit battery backing up four 32k x 8 bit static rams. The battery has swollen, presumably burst, and dribbled it's contents down this card. Also on this card is the interface to the Probe, the MPG module and the I/O module
It is possible that this card and sub-module are recoverable, but it would be highly desirable to replace them . Apart from the 48 pin big i/c which I assume to be a custom LSI, all the other i/c's are standard LSTTL from the 7400 range
Post by: awemawson on June 13, 2018, 06:28:32 AM
There is another plug in battery compartment suspended above the CRT - not yet been able to withdraw it, and also there is another logic crate labelled up "MPG Module" and "I/O Module" which interfaces to Card B via an umbilical cord with that very corroded plug.
. . .oh joy . . . off to google these cards . . . :coffee:
"Card B" = 570 212 9202.10
Sub Module with the RAM & Battery = 570 342 9101.00
Post by: Spurry on June 13, 2018, 08:41:08 AM
I wonder how long it took to get to that state...
Pete
Post by: awemawson on June 13, 2018, 10:15:54 AM
Progress report - that badly corroded Card-B - I've manage to source one in Germany for a modest £50 including postage, but not the little sub module yet. I can find very similar ones that have some components missing from the board. I suspect that as the controller evolved they went away from battery back up and went to NV Ram, altering that little board to suit
I have powered up the Power Supply and the 5 volt line at least is working - it provides +5 volts and and +/- 15 volts but I can't find a convenient point to monitor the +/- 15. I took a chance and plugged all the cards back other than Card-B and the PSU held up , there was static on the monitor screen and the one LED on the cards illuminated
Post by: nrml on June 13, 2018, 10:39:55 AM
Post by: awemawson on June 13, 2018, 11:12:58 AM
Basically they are microprocessor driven computers with many custom algorithms for motion control, and I/O (input / output) to suit the application. So that horrid card that I'm calling 'Card-B' has on it battery backed RAM memory for machine parameters, an interface for the probe, and a bus highway driver to a remote set of I/O mainly hidden under the controller in the MPG and I/O crate (Shown in the picture above 'More Electronics') This seems to have got off lightly with just one corner affected. I will have to pull it out and clean it up, but I >THINK< it's recoverable :scratch:
The white deposits remind me of dry rot fungus :bugeye:
Post by: NormanV on June 13, 2018, 11:20:53 AM
Is that English? I have no idea what you are talking about.
I was brought up making cardboard boxes, they're a lot easier for me to understand than electronics, but I am still enjoying the story. :beer:
Post by: AdeV on June 13, 2018, 02:52:22 PM
Is that English? I have no idea what you are talking about.
hehe, tech speak is a bit of a language all to itself...
I understand most of it, not sure what an MPG is (that was always Miles Per Gallon to me...), but I'm sure there's a perfectly rational alternative :scratch:
Post by: awemawson on June 13, 2018, 03:03:33 PM
Post by: NormanV on June 13, 2018, 03:23:40 PM
Oh, that's ok then.
Post by: nrml on June 13, 2018, 03:24:12 PM
I presume the battery on the replacement board will be remotely mounted for safety and easier access.
Post by: awemawson on June 13, 2018, 03:38:22 PM
I suspect if I were brave, a good wash in hot water might dissolve a lot of it, and where rust has been washed down a card, a light brushing of citric acid to remove the Fe2O3, but I'm not sure what effect it would have on the tinning on the ic's legs. It also rather depends what's been washed under a chip. Some of the devices are surface mount so no gap but stuff will have crept into the tiny space that must be there.
I've just made an offer to a chap in Germany for one of the battery backed memory cards - problem is it is mounted on a 'Card-B' (my notation) and he is asking rather a lot. My offer is for the sub-card. Fingers crossed - you never know he may accept.
Post by: nrml on June 13, 2018, 03:42:54 PM
Post by: awemawson on June 13, 2018, 03:55:45 PM
Post by: Pete. on June 13, 2018, 04:21:33 PM
A few weeks ago a guy at work spilt a whole large cup of coffee onto his gaming laptop. He took it to a repair shop and they pronounced it non-repairable, all it had was a single red flashing led when you tried to power it. They couldn't even get it started to allow him to recover files plus the keyboard was integrated into the chassis so that was non-removable too and obviously full of dried-up sticky coffee.
I carefully pulled off all the keys and popped all the plastic moulding pins to get the coffee out of the keyboard, but the board still would not start. In desperation I washed it (the motherboard) in the kitchen sink by squeezing out a sponge wetted with very hot water and scrubbing the whole board off with the damp sponge, then I left it under a heat lamp to dry. After that it fired right up, and it is still running weeks later, though it does tend to get hotter than it did before.
Post by: awemawson on June 13, 2018, 04:33:59 PM
We used to put their faulty keyboards through the dishwasher, taking them out after the rinse but before the dry cycle. They then went into the equivalent of an airing cupboard for a few days. The vast majority worked after this treatment :thumbup:
(I learnt this trick during recruitment interviews - I'd placed a 'staff wanted' advert in the paper in the town where the previous maintainer was based, and of course attracted several of their employees. More than one of them revealed this trick, which we shamelessly copied :clap: )
Post by: seadog on June 13, 2018, 04:50:30 PM
Post by: PK on June 13, 2018, 06:29:59 PM
I suspect if I were brave, a good wash in hot water might dissolve a lot of it, and where rust has been washed down a card, a light brushing of citric acid to remove the Fe2O3, but I'm not sure what effect it would have on the tinning on the ic's legs. It also rather depends what's been washed under a chip. Some of the devices are surface mount so no gap but stuff will have crept into the tiny space that must be there.Isopropyl alcohol is the go to solvent for 'first go' cleaning of things in the electronics business. Toothbrushes and ultrasonic cleaners work about as well as each other. Anything that's going to chemically react with corroded metal is going to react with the tinned leads.
Glad to hear you found a replacement board. If you get REALLY stuck, it is possible to re manufacture a board, we've done it before for a customer who just couldn't sort the problem out any other way. If it's only a two layer board then that's a bit easier as you can trace the layout with a scanner after floating the parts off in a solder bath. Anyhow, hopefully you won't need to go that far.
PK
Post by: awemawson on June 14, 2018, 03:58:40 AM
Drawn in Autocad, saved as a .DXF, imported to SheetCAM, ported to MACH3 and cut out of 2 mm Zintec steel on the CNC Plasma Table then bent on the Edwards Box & Pan folder- the Plasma table certainly makes this sort of thing so much easier.
It sits nicely but some how I want to bolt it to the bars, so when they are withdrawn it stays as a single unit, but I want to preserve the undrilled top surface - might need to break out my stud welder and see how accurately I can place studs - I can see it will be useful for paper work at the monitor when it's original purpose of removing and replacing the controller is done with :thumbup:
Post by: awemawson on June 14, 2018, 11:21:58 AM
It wasn't cheap, but I reckon a better solution than trying to clean up the originals - however I will keep them and perhaps have a go in the future.
Still need to clean up the I/O crate (not got it out yet!) and also try and get the rust off the main controller crate. I may try masking it and using my 'spot sand blaster'
Post by: awemawson on June 14, 2018, 03:20:36 PM
Then mounting the shelf and wiggling it into the centre of its movement latitude I marked though the holes with a Sharpie, and then gave the marks a decent sized centre pop.
Digging out my Stud Welder (*) I did a few test firings to prove my settings then I located the pip in the M5 x 18 mm studs I was using in the centre pops and fixed four studs. Amazingly they fitted the bars, and being 18 mm they don't protrude below the 3/4" bars.
. . . so objective achieved - an unblemished upper surface and the bars and shelf now together as a unit :thumbup:
The Stud Welder can go back to bed for another long sleep :ddb:
* https://madmodder.net/index.php/topic,10287.0.html
Post by: awemawson on June 15, 2018, 07:24:46 AM
Access a bit tricky - have to go through where the Manual Control Panel mounts - so that has to be removed first. I twisted the cable ident labels so hopefully I can see them in my pictures and get them back in the correct places :ddb:
I took many more pictures of the wiring but they are BORING !
Post by: awemawson on June 15, 2018, 07:34:06 AM
Usual thing - three screws no problem, but the fourth was rusted solid. A candidate for drilling as the bit it goes into won't take heavy hammering. Placing a rare earth magnet next to it to catch the swarf I drilled it out, constantly checking drill depth as if this blind hole were extended too far it would go into the tailstock end inners of the machine that will be awash with coolant (hopefully some time!)
Post by: awemawson on June 15, 2018, 07:38:34 AM
Post by: awemawson on June 15, 2018, 07:44:25 AM
Now actually the physical damage is not too bad to the inner IO card - I'm sure it could be recovered, but finding one on the ubiquitous eBay for only £35 including postage it seems silly not to replace rather than try a repair
Post by: awemawson on June 15, 2018, 07:51:04 AM
. . .EXCEPT . . the fellow on ebay flogging the I/O card had another offering of the sheradised metal panel AND the umbilical cord with connectors both ends, that was so badly corroded at the controller end - so an excellent result (if all the cards work!)
I grit blasted the Beaver made white panel and have re-sprayed it to await the other bits to fix to it.
Post by: vtsteam on June 15, 2018, 08:56:03 AM
Post by: awemawson on June 15, 2018, 12:21:54 PM
Until the bits arrive there will be little more progress but this afternoon I've re-glued the corner of the Control Panel that was broken (not me gov!) and started sorting the corrosion on the card cage.
The rusty retainer with a sheared bolt in it I was able to remove by drilling out four pop rivets - then it could be grit blasted, the sheared screw drilled out and the hole re-tapped, and then the lot got a light coat of zinc spray before being re-rivetted. Note how I insert ALL the rivets before setting any to ensure that the location stays OK
The card guide bar, which is alloy, is more of a problem and I think I'll need to source a replacement. There are two sheared off screws in the square nuts that are supposed to slide in the extrusion - but they don't. The plastic of the guides themselves is very brittle and two have broken retainer pegs, and the bar itself is badly corroded.
Do any on you recognise the rack system to help sourcing a bit of extrusion and some guides - there is a logo in the molding of the guides, I recognize it but cannot recall who's it is - can YOU help ??
Post by: awemawson on June 15, 2018, 12:25:02 PM
Post by: awemawson on June 15, 2018, 12:45:09 PM
. . . now where is my 7.5 mm x 3 mm flat bar stored :scratch:
Post by: tom osselton on June 15, 2018, 03:59:53 PM
On reflection, although I'd prefer to replace the extrusion, as a fall back , and if I can bully the current captive nuts out and down the extrusion, all I need do having cleaned it up, is make a length of tapped flat bar to slide in. 7.5 mm x 3 mm tapped every 20 mm nine times. There are two unused card slots, so I can steal their guides to replace the ones with broken retainers.you mean this guiderail?
. . . now where is my 7.5 mm x 3 mm flat bar stored :scratch:
https://www.partsfinder.com/parts/siemens-medical-solutions/1097492
Post by: awemawson on June 15, 2018, 05:11:45 PM
Post by: awemawson on June 15, 2018, 06:05:48 PM
Post by: vintageandclassicrepairs on June 15, 2018, 07:34:04 PM
Maybe one of the forum members in the supplying country (is it USA?) would step up and
buy the parts and post them on to you??
John
Post by: seadog on June 16, 2018, 03:29:31 AM
Post by: awemawson on June 16, 2018, 06:43:41 AM
I was determined today to try and clean up the bar extrusion and see if I could remove the corroded nuts and make a tapped bar to slide in in their place. It turns out that the orange plastic bit is one continuous bit rather than one per nut as I had thought. A bit of brutality got it and the nuts out, and I attacked the extrusion with a file followed by a wire wheel.
There is a big chunk dissolved away by the leaking battery, but it's not affecting the functionality and actually it cleaned up pretty well. I hunted around in my scrap brass box and the only suitable thickness that I had was one leg of a bit of angle that was barely long enough -but you use what you have. Being angle made holding it for drilling and tapping easier than had it been already a correct sized strip.
So this got marked up, centre drilled, tapping drilled and tapped M4 under power
The hole spacing is 20 mm EXCEPT for the one at the far end which is 15 mm - this nearly tripped me up, but luckily I spotted it just at the last moment. Anyway - offer it up for a reality check - yes it looks about right :thumbup:
Post by: awemawson on June 16, 2018, 06:55:22 AM
This was followed by a bit of a clean up, then I slid it into the extrusion and re-mounted the extrusion to the card cage.
PCB Guides: Two were beyond use, their location pins having broken off when they came out, BUT three slots in the cage are not used, so the obvious solution is to steal their guides :clap:
Popped the required guides into the relevant places, and did a trial insertion of the cards which went well and everything fits nicely.
(I couldn't bring myself to put the card with the leaking battery back !)
So now cosmetically it all looks a lot better than it did - look at the last picture to see how it was
Post by: seadog on June 16, 2018, 09:20:21 AM
Post by: awemawson on June 16, 2018, 01:13:20 PM
I've investigated the possibility of 'Powered Tooling' being mounted in the tool turret, and sure enough the facility is there - the selected tool gets lined up and has a simple 8 segment dog clutch on the rear of the VDI40 mounting spigot, that engages with it's opposite number on the tool drive
Pulling the monitor apart it turns out that it is a colour one - or at least the drive signals entering it are marked as 'H V R G B' and researching the controller, one of the memory cards is only fitted when a colour monitor is fitted. Seller thought it was green phosphor only so this is a bonus. Not that I'm much closer to seeing anything on the screen !
As well as the mechanical Tool Probe, it looks as though at one time it has been equipped with an optically coupled probe, presumably mounted in a tool port on the turret. The clue is that there is an optical sender / receiver mounted on the same plane as the Renishawe Tool Probe socket. No sign of the actual optical probe though.
Post by: awemawson on June 17, 2018, 01:11:54 PM
I wanted to prove the PSU was OK but only the +5 volt output had test points. I was fairly sure that it also was supposed to put out +15 v and -15 v. Pulling the PSU apart it's only output connector is a three row 96 pin Eurocard type. I was surprised to find that mains for the 240 volt rack fans is routed via this connector. Inside I found a pair of 15 volt regulators confirming my suspicion, and also a Ferranti Uncommitted Logic Array - in a PSU for goodness sake WHY ?
Soldering a pair of 'wire wrap' square gold plated pins to my test probes I was able go along the crate back board and find the 15 volt lines powered up, so that's looking good.
Then I turned my attention to some of the card retaining screws that had sheared off. They are M4 but have an extended outer part with a hand grip, and a turned down section to retain them in the card. Drilling tapping and Loctiting replaced the sheered threads.
Then it was a case of 'hunt the battery' The one in the back of the monitor was easy - it's an SL2770 and RS Components carry it. However the one on the little RAM card proved more elusive. The original is in far too bad a shape to take reliable measurements from, but eventually I found an image on the web that revealed all - it's an SL886. There are two versions, one with pins and one with pads, and the original and the image I found don't help the diagnosis, so I will wait until the replacement card arrives to see which before I order.
Strangely the data sheet for the SL886 give it's weight as 21 grams, and my ruptured one weighs EXACTLY 21 grams despite all that death and destruction that it has oozed :scratch:
Apart from posting pleas for help on Practical Machinist and CNC Zone that's about it for today.
Post by: PekkaNF on June 17, 2018, 02:30:29 PM
.....
I wanted to prove the PSU was OK but only the +5 volt output had test points. I was fairly sure that it also was supposed to put out +15 v and -15 v. Pulling the PSU apart it's only output connector is a three row 96 pin Eurocard type. I was surprised to find that mains for the 240 volt rack fans is routed via this connector. Inside I found a pair of 15 volt regulators confirming my suspicion, and also a Ferranti Uncommitted Logic Array - in a PSU for goodness sake WHY ?
....
If my memory serves right S5 135/150 series simens PLC rack had somewhat similar looking PSU module. I once had trouble with it. I was chasing non responsive CPU-card, when in fact the problem was "power good" sort of signal from PSU module. There were some handshake signals with busscontroller card/cpu/psu, it was not clear without consulting the technical manual, which we luckily had. If I remember right cpu had enough power to do post startup check and then fiqure out not to talk to bus, because status from PSU was not correct. It was all pretty odd to have some "logic" on the PSU, you might think that it just posts "power good" and that's it.
Not sure if this is relevant, but that was my personal encounter.
Pekka
Post by: awemawson on June 17, 2018, 04:39:01 PM
There is a pair of external terminals on the PSU labelled "Power Supply OK" - they are not connected, but of course may also be routed internally to the backboard of the logic crate. They seem to be a N/O relay contact that closes a second or two after the PSU is powered up. Certainly they change state when the 'Reset' button on the PSU is pressed then revert to the closed state after a second.
Of course I have no idea whether relay open or closed is the good state, but as with no mains they are 'open', the likelihood is that 'closed' is 'OK'
Post by: PekkaNF on June 17, 2018, 05:33:31 PM
Post by: Pete W. on June 18, 2018, 05:48:39 AM
I've just been catching up on this thread, reading back to page 2 where you write about battery leaks. I have some battery holders for ½ AA size lithium batteries (as used on old Mac computers). I also have a few of the batteries as well (unused but they've been on the shelf for a few years). If they'd be any help to you I happily put some in the Post.
Post by: awemawson on June 18, 2018, 07:17:47 AM
I am going eventually to re-mount the batteries in a more accessible place, but will use the same type as original, and probably install capacitors across the leads where the batteries currently are to guard against stray pick up of noise.
Post by: awemawson on June 18, 2018, 03:43:03 PM
Previous owner had left it outside to rust so it needs grit blasting and then spraying. Suggestions please for a suitable oil proof paint that will stand total immersion for long periods.
Post by: DICKEYBIRD on June 18, 2018, 06:42:25 PM
TSuggestions please for a suitable oil proof paint that will stand total immersion for long periods.POR15 gas tank sealer maybe? I used some of their rust paint on a rusty Ford floor pan & it did very well. Dries glass-hard & seems to be very inert. I would think their gas tank sealer would be even better.
Post by: WeldingRod on June 18, 2018, 08:37:51 PM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on June 19, 2018, 05:41:02 AM
But crawling on hands and knees to see if there was enough vertical clearance to put the tank on rollers (there may be) I made a DISCOVERY . There is a further big panel that can be removed at the back of the lathe (it's about 1 metre square) that I had previously missed. Taking it off it revealed that the original top of the coolant tank has been stuffed in there along with the coolant pick up and pump - just as well I found it before anything starts moving as the pipes are laying on the Z ballscrew. BTW the Z servo motor is HUGE !
Being able to get my head in the back of the machine here has let me have a better look at a mystery louvred metal box fixed on the rear of the axis drive amplifier cabinet. It's 15" wide x 9" deep x 20" tall, has a single umbilical cord of Adaptaflex trunking going into it and absolutely no markings what so ever. I suspect that it houses a transformer or maybe from the shape several transformers :scratch: Perhaps I'll be able to open it up sometime.
Post by: Pete W. on June 19, 2018, 09:28:20 AM
Pete that is an extremely kind offer, but these are very high capacity units. The cylindrical one is 8 ampere hours with a 10 year life expectancy so I don't think 1/2 AA would cut it in this instance.
I am going eventually to re-mount the batteries in a more accessible place, but will use the same type as original, and probably install capacitors across the leads where the batteries currently are to guard against stray pick up of noise.
Fair enough. I've just looked up the capacity of the ½ AA size lithium batteries and it seems to be only 1.2 Amp hours.
Post by: awemawson on June 19, 2018, 11:19:09 AM
Post by: awemawson on June 19, 2018, 11:24:03 AM
It looks slightly better than it did :ddb:
Post by: awemawson on June 19, 2018, 11:29:18 AM
Apart from bally inaccessible screws it went well. I could then start re-wiring the Control Panel ready for re-fitting
Post by: awemawson on June 19, 2018, 11:36:00 AM
I've put the Control Panel back in place, but only with three screws - pushing my luck I suspect to 'assume' all is well in there
. . .that brings me to the end of the first week of working on the Beaver Lathe, and I think quite a lot has been achieved. But a long way to go yet I suspect before it's back up and running.
Post by: Pete. on June 19, 2018, 02:55:34 PM
Is all that damage from one little failed battery Andrew or is there another source for the corrosion?
Post by: awemawson on June 19, 2018, 03:31:10 PM
So as I'm going to have to wait a week or so for the Interface card and it's RAM Daughter Board to show up I thought that I might as well set the Coolant Tank up de-rusting with citric acid.
First I gave it a good thumping and scraping to shift as much loose rust as possible. Tipping out the loose made quite a pile. Then I blew it out with an airline, and set it up on 'builders trestles' strategically close to a drain and very carefully levelled it.
Then came bucket after bucket of hot citric acid, filling it until there was a meniscus visible so that hopefully the underside of the top surface will be wetted as well.
At least this has shown that there are no pin holes (YET!)
Covers over it over night to stop any wild life drinking it and dying :bugeye:
No doubt it's going to take quite some time to have it's beneficial effect, meanwhile I can try and decide on a paint treatment that is affordable (large tank this!) and effective.
POR15 would be nice as would Glyptal but either would bankrupt me. The other suggestion has been marine quality two pack epoxy paint
Post by: chipenter on June 19, 2018, 04:09:25 PM
Post by: awemawson on June 19, 2018, 04:22:24 PM
Post by: AdeV on June 19, 2018, 05:05:47 PM
But doesn't it need extensive air fed masks etc?
It depends on whether you're sensitive to cyanoacrylates... apparently you can cheerfully paint away with 2-pack until one day your lungs pack in... or you can avoid the danger & use air-fed masks, etc., as you say.
Post by: Will_D on June 19, 2018, 05:14:54 PM
Seriously though:
2 pack car paints sprayed in a sealed spray booth need an air fed mask.
Spray outside, be upwind of the painted object?
I used 2 pack brushed yacht paints (International 2 pack) with no problems. Am sure this could be sprayed without too much problem.
A lot depends on the chemistry of the two pack products! AFAIK Aralidite does NOT contain a breathing vapors health warning
HTH Will
PS: More pig info/pics please
Post by: awemawson on June 19, 2018, 05:23:50 PM
http://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm
Post by: vintageandclassicrepairs on June 19, 2018, 05:51:26 PM
Would galvanising the tank be an option?
The last lot of hot dipping I got done was very good value
John
Post by: awemawson on June 19, 2018, 06:01:41 PM
Post by: mc on June 19, 2018, 06:24:39 PM
My thoughts would be to speak to an industrial paint supplier, as they should have knowledge on what will withstand oils/coolants.
A quick google for milling machine paint, just threw up http://www.paragonpaints.co.uk/home.php
Certainly better priced than POR stuff, but probably worth a call.
PS you've obviously got too much spare time to do all these projects!
Post by: vtsteam on June 19, 2018, 09:27:07 PM
Post by: awemawson on June 20, 2018, 03:04:19 AM
Whatever I use I'm coming to the conclusion I'll have to cut open the top panel of the tank to get proper access. Then a bit of redesign to refit a top.
Post by: awemawson on June 20, 2018, 06:41:07 AM
Thanks for the suggestion Steve :thumbup:
The citric acid seems to be doing a good job, after a day or two I'll drain it down and see if any of the old paint is still sticking wants to come off with a scraper.
Meanwhile knowing that most chemical reactions work faster when warm I've set up a radiant propane heater playing on the tank. Be far better were it pointing upwards from underneath, but you use what you have!
Post by: awemawson on June 20, 2018, 07:20:15 AM
A quick removal of the heating head (hold with pliers - still VERY hot) , balance on a 'JCB to Cambridge Ring Roller Adaptor' , light it up again and we'll soon have those fish boiled :clap:
Post by: vtsteam on June 20, 2018, 07:27:32 AM
The brand has now diversified into many disimilar paints, including latexes, and all in one finishes, etc. So it becomes confusing. But the original quart cans of the brush oil enamel is still widely available here, and that's what i use for machinery, or anything else metal in tough service.
Post by: vtsteam on June 20, 2018, 07:37:34 AM
Post by: awemawson on June 21, 2018, 12:45:39 PM
Last night the 'tank heater' actually got the citric acid up to 43 degrees Centigrade before I turned it off. This morning the objective was to drain the tank, sand blast it and paint it in Rust-Oleum assuming the paint got delivered.
It started off well - I set the tank draining first thing before I fed the livestock, and it was just dribbling when I'd finished breakfast. So I removed the Level Gauge and Tap, and set it up for Grit blasting. The citric acid had done its work and the horrid flaky rust was all gone with an almost shiny surface left. There was however a lot of what ever that it had been painted with - a very resilient black hard paint.
Grit blasting was going pretty well, except that the black 'paint' (it must be something tougher than paint) wasn't shifting very easily with the grit blaster. I tried hot strong caustic soda solution, and some paint stripper of the sort that stings your hand through rubber gloves, neither had much effect. I reckoned that the Rust-Oleum would be happy on top of it as it was obviously stuck well :clap:
At this point I decided to check the diesel level in the compressor, and just as well I did. There was a fire raging at the far end of it's cabinet. Not a little baby thing, but a raging inferno blown by the radiator fan of the compressor. :bugeye: :bugeye:
I shut the engine off and high tailed it into the workshop to grab the CO2 extinguisher that I'd placed next to the laser engraver when I got it.
A couple of blasts put most of it out, just a bit still burning on the hot silencer - another squirt and it was out - but WHAT had been burning? Some fluid - I tentatively started the engine again, and something was being blasted through the air and oil coolers by the fan onto the hot exhaust - but what :scratch: All too bally hot to investigate so I went and had lunch while it cooled a bit.
Returning half an hour later, again I started her up, but this time holding a powerful torch which revealed diesel leaking from a hose and being fanned all over the place. All it was in the end was a loose hose clip which when tightened was fine - but it could have been a disaster. Togged up in the blasting gear I would neither have heard nor smelled the fire, so I was very lucky something told me to check the level in the tank :med:
So back to the task in hand - I blasted the tank all over, a very tedious long winded job, then blew out all the sand with the compressor and set it up for painting.
A slight delay as by then it was feed time for the pigs (obligatory pictures to satisfy Will-D !) Then I painted the tank with a long armed 'radiator roller' inside and outside. I'll leave it over night and give it a second coat in the morning assuming this coat is dry.
Then pack up the sand blaster followed by a badly need shower and an even more badly needed glass of Old Speckled Hen :lol:
Post by: awemawson on June 21, 2018, 02:15:37 PM
While I was blasting, fire fighting and painting DPD crept in and delivered a parcel from Germany containing the Battery Backed RAM Daughter Card, and the Interface Card - best part of a week AHEAD of schedule :thumbup:
So after a very careful inspection and copying session for option jumpers in they went :
:ddb: :ddb: :ddb: AND THE CONTROLLER SPRANG INTO LIFE :ddb: :ddb: :ddb:
. . . phew, it looks like the gamble may have paid off and this lathe might once more return to active service !
Lots more to do to restore the various bits of data so it knows which lathe it's running in, and you can be sure that there will be a few 'Gotchas' along the way but most definitely PROGRESS with a capital P
Post by: Pete. on June 21, 2018, 02:35:31 PM
This would be the point at which I would consider myself properly 'on the road'.
Post by: awemawson on June 21, 2018, 03:32:53 PM
Post by: pycoed on June 21, 2018, 03:59:30 PM
Post by: Will_D on June 22, 2018, 04:59:28 AM
Post by: awemawson on June 22, 2018, 06:18:32 AM
This morning I gave the outside of the coolant tank a second coat (no pictures - one coat looks much like another!) When this has hardened a bit, probably tomorrow, I'll invert it and give the inside another coat.
Then the Postman (Steve) brought me two 40 BAR flange mounted hydraulic gauges to replace the rather unreadable ones on the machine. I'll need to be able to read them as I commission things.
#1 Gauge monitors pressures associated with the automatic chuck, and #2 does the same for the tail stock.
All these gauges are glycerine filled for safety, and the originals both had cracked plastic lenses that were bulging ominously and the glycerine had leaked out, so best replaced.
Post by: hermetic on June 22, 2018, 01:22:44 PM
Phil.
Post by: awemawson on June 22, 2018, 05:51:21 PM
I thought that one of the 'Gotcha's ' had caught me this afternoon. I was experimenting putting binary data into the part of the control memory that sets up the serial port. I could put '1's ' in no problem, but not '0's ' :bang:
Turned out that in fact three numbers weren't working on the keyboard so probably a 'select line' on the decoder, so either something on the interface card that I installed yesterday, or just possibly a bad connection.
Leading from the key matrix and the LEDs on the front panel are those very thin flexible PCB 'cables' pushed into the gripper type connectors. I took them all out, cleaned and sprayed them with contact cleaner, and PHEW - numbers now working :thumbup:
It seems that this controller is a half way house between two generations of the control, so I'm having to interpret instructions rather than just obey them. I think possibly the University had a peek at what was coming and wanted it early.
Post by: awemawson on June 23, 2018, 04:12:54 AM
I liken the painting of this tank to an Ocean Liner - pretty from a distance, none too brilliant close up but functional. And after all I'm applying the paint in the same way they paint liners - with a long handled roller.
So while I was in scruffy clothes I thought that I might as well do a job I've been putting off for a few days - rolling on the ground installing the three remaining levelling feet and pads. When the machine was delivered it was placed on the four pads roughly at the corners and levelled, but these three are right in the middle surrounding the tunnel into which the coolant tank goes, so they needed fitting before the tank can go back.
Trivial job - unscrew the ball ended bolt - slip the pad with a domed recess under the ball end - tighten the bolt so it just bears weight - what could be easier :med:
Answer: not having to do it at arms length down a tunnel 6" tall by 18" wide using spanners that you can barely lift with your arms outstretched :bang:
First one wasn't too bad, but the ones down the far end of the tunnel were . . .challenging . . . :clap:
All done now though, so I can climb back into clean clothes, have breakfast and take the dogs for a walk (wife in Houston for the week staying with youngest son)
Post by: awemawson on June 23, 2018, 04:59:52 AM
Never mind - get on with it. They fit into my cabinet blaster but using the Hydrovane compressor would take too long. Some time ago I plumbed a 'Claw Fitting' onto the outside wall of my welding shop connecting the internal compressed air system via a ball valve. So connect up the Road Compressor (no fire this time !) blast them, and use your last roller to paint them (memo to self, buy more roller pads)
Post by: AdeV on June 23, 2018, 06:25:57 AM
I liken the painting of this tank to an Ocean Liner - pretty from a distance, none too brilliant close up but functional.
I believe the Americans call this a "20ft paint job". It looks great.... from 20ft away :lol:
Post by: awemawson on June 23, 2018, 06:56:19 AM
Actually the finish isn't that bad considering it's grit blasted rust, but not car body standard !
Post by: vtsteam on June 23, 2018, 10:08:53 AM
Post by: awemawson on June 24, 2018, 01:21:03 PM
I've been trying to re-load the back ups of the parameters that I obtained back into the controller. The available documentation is vague to say the least. Having eliminated cable issues (I'm re-using the RS232 cable that drove the Traub) by belling it out against the Siemens documents I then had to juggle the usual 'how many data bits, odd, even or no parity, what baud rate, which signals are in control RTS/CTS DSR/DTR or is it using XON/XOFF - is is ascii or is it EIA coding.
I started trying to dump from the controller and comparing the format with the back ups that I had. It was at this point I found that the port I was using on my multi RS232 box was blown. OK no problem I had a spare port. One of the problems was that a required '=' character was coming out as a 'NULL' - eventually traced to a parameter defining what code the '=' character is. Guess what it was set to '00000000' or NULL !
Then after much Googling and lots of :scratch: and :coffee: and a bit more :scratch: I came across a posting from years ago from my late lamented friend Mark McGrath helping someone else with the same issues. So I blatantly copied his 'setting bits data' into the controller and was able to load some of the less vital stuff, like tool offsets and something called 'R-parameters' that are essentially variables used in canned cycles, but wasn't able to load the vital stuff like the PLC program and the main parameters for the control.
There is obviously something obvious here that I'm missing, and after so many hours at it I decided it was time to walk away from it and clear my head
. . . anyway there's supper to cook !
Post by: Pete. on June 24, 2018, 02:29:12 PM
Post by: awemawson on June 24, 2018, 02:50:58 PM
Hood on the MIG welding forum has a friend (called Forbes but not Peter) with a TC-15 Beaver lathe (slightly smaller than mine) that they have retrofitted with MACH3. By one of those amazing co-incidences it was sold to his friend (without the 820T controller) by the aforementioned Mark McGrath before the poor chap popped his clogs.
. . . .small world isn't it
(Mark was a friend of John Stevenson, and Tim Leach, and Peter Forbes . . the list goes on . . . all lost to the big C )
Post by: awemawson on June 24, 2018, 04:45:44 PM
Prior to this some more extensive Googling turned up a reloading guide written by Siemens - seems much the same as I've previousy followed, but I'll work through it word by word tomorrow when I'm back from picking up the pig food.
Post by: vtsteam on June 24, 2018, 11:09:25 PM
I feel your pain especially re. the non-standard mfr.. innovations, like slightly altered ASCII, and the joys of RS232 trial and error com parameters (and cable terminations). Always fun if those params also can be user DIP switched to alternatives, or even re-written to static battery backed RAM, no longer battery backed.
But I know you'll crack it in the end. These things only have a million or more combinations. And there will be a breakthrough somehow, or through someone. 99% of them are due to somebody not explaining something "special" onboard in the right terminology, or at all. You'll get it. :beer:
Post by: awemawson on June 25, 2018, 09:20:48 AM
Having got the pig feed I was free for a bit to try that new document. It >almost< works - still a bit fuzzy where they talk of changing from German to English, as if it is already in English some of the steps described are still needed. However the main controller software is now loaded. One file, which appears to be a main memory dump of all the programs, took nearly half an hour to load at 9600 baud.
The one file I'm missing is one of type 'PCA' which cross references error numbers to error text apparently. But if you look at the picture below at least some of the error numbers are translated :scratch:
Incidentally all those errors are expected - it's reporting errors on the various servo systems - not surprising as they are not connected.
ps Will_D where were YOU when I had to unload quarter of a ton of pig feed with only the dogs to help :lol:
Post by: awemawson on June 25, 2018, 02:29:41 PM
I replaced the level gauge and drain tap on the coolant tank, then went for a dance with it, shimmying it into place. I was sure it would fit as I'd tried with a wooden mock up some time ago, but the workshop is a bit crowded round the back there and it was a relief when it was in place.
Then I loosely re-fitted the plate with the coolant pump on board just to see how everything fits together. I suspect that this pump came off ten years ago !
I've done a modest bit of investigation round the 'tripping 100 mA RCD breakers' issue. I'd suspected the main spindle drive - a "KTK Mentor" 26.5 kW DC spindle drive. I've not been able yet to source a manual for this model, but the 'Mentor 2' that replaces it says it could have leakage up to 185 mA :bugeye:
However, with mains disconnected, measuring from phase input to chassis ground I am measuring 300 ohms, and if the breaker for the Mentor is opened this 300 ohms goes away. Now this isn't conventional chopping high frequency leakage - the power is off and I'm measuring with a DC ohm meter (Avo 8) but if the drive is powered up (no earth on the chassis :bugeye:) the drive comes up and says it's ready to play
Maybe there's a dead mouse in there somewhere - a job for tomorrow I think.
Post by: awemawson on June 26, 2018, 09:25:17 AM
Consistent approx 300 ohms 'phase to chassis' with the huge breaker giving the KTK Mentor it's 415v 3 phase closed , but clears with breaker open. First job, open up the KTK Mentor DC Drive.
Well I really thought that I'd found the fault - several 0.1 uF capacitors in a very sorry state. So I disconnected the terminals putting power on the device, but noticed that there were much thinner cables going elsewhere.
Measuring to the cable ends the 300 ohms problem was coming NOT from this bit of the Mentor, but the small cables - but where do they go? A major bit of trunking dismantling and cable tracing found that they went down to the bottom of the KTK Mentor via some smaller fuses.
Isolating the fuses the fault persists (so not this bit of the Mentor drive), but hang on, there again is another cable coming off these terminals back into the trunking - but to where?
Answer - it goes to a small motor starter unit, who's output cables plummet down to the main termination rails at the cabinet base FOR THE FAN FOR THE MAIN MOTOR. Faulty fan perhaps, yet I know it turns as that was one thing I got going on site before I bought the machine.
But hang on what is that white domestic looking three core flex doing connected there and why is it's blue neutral wire connected to earth.
Answer: some plonker has decided to add a Ventaxia Window Fan to the roof of the cabinet that houses the turret electronics and a pair of 24 v power supplies. This machine has no neutral feed, so Mr Plonker has used Earth instead :bang: I've temporarily isolated the fan.
So the elusive 'earth leakage fault' has proved to be someone in the past doing silly things. Now the machine happily starts up on my 100 mA RCD protected supply without tripping, and I can consider returning the Sinumerik 820T controller to it's proper place, but before then I must decide what I am doing about relocating the batteries that caused the problem in the first place - replacements arrived today.
. . . mind you those 0.1 uF capacitors will need changing before long
Post by: charadam on June 26, 2018, 11:45:24 AM
I must however sound a note of censure - your boots man, they are a disgrace!
I offer in evidence post #106.
Post by: awemawson on June 26, 2018, 12:23:33 PM
They are 'Crocs Bistro' of the unvented side variety in white (yes honestly!) intended for the catering industry and I get through three pairs a year. This particular pair were actually thrown in the bin a few weeks ago, but I rescued them when I was Creosoting those chicken sheds, as the stuff goes everywhere. I do like to properly wear them out and get my monies worth.
I wear Crocs all day every day about the farm, or if I'm walking the dogs in the woods or countryside, and as I take UK size 13's which are difficult to find I buy them well in advance if any turn up at a sensible price - I do have four brand new pairs in stock for future use :ddb:
Post by: awemawson on June 26, 2018, 05:02:12 PM
What he SHOULD have done in this situation where no Neutral is available, is to use a small transformer primary between two phases (415 volts) and secondary giving a floating 240 volts. The fan can still be earthed (though it wasn't !)
But what size transformer? Well I can't find a model number on the Vent Axia so I needed to measure the current draw rather then look it up. So I temporarily wired it to 240 volts leaving a long enough neutral wire for my Fluke clip on meter to measure the current.
Answer : 200 mA . Now I'd expected a start up surge, but actually it starts at 100 mA then increases to 200 mA. so a 50 VA enclosed 'panel transformer should do the job nicely - off to eBay to find one :clap:
Post by: Pete. on June 26, 2018, 05:23:27 PM
Post by: awemawson on June 26, 2018, 05:35:35 PM
Post by: awemawson on June 27, 2018, 06:25:16 AM
The capacitors turn out to be PME261JC6100KR30 by Rifa and are 0.1 uf at 1000v DC / 500v AC - available in stock from RS but at quite a price. By Googling I discovered a place called Mercateo that I've not come across before that were noticeably cheaper - order placed.
So looking at the power board for the drive it is pretty daunting with loads of connections all waiting to trip me up, however sitting down and studying pictures of it, and working out which bit did what in fact it doesn't look to be too bad (famous last words!)
I took one of my pictures and annotated it to get things a bit clearer in my mind.
Post by: awemawson on June 27, 2018, 12:44:16 PM
The Optical Receiver and interface unit are still in place, and amongst the scanty documentation is the installation manual and test certificate BUT NOT THE PROBE.
. . . no, not the probe 'cos the chap who I got the other probe from flogged it on eBay back in April :bang: :bang:
(amazing what a bit of data mining reveals!)
Come on empty your pockets - who's got a Renishaw LT02 probe for me
Post by: AdeV on June 27, 2018, 03:54:10 PM
Chances are, that cap is entirely surplus to requirements, and it's rather sorry state is due to the fact it's already gone bang & let out the magic smoke.
Still... better in than out (as no-one ever said). :nrocks:
Post by: awemawson on June 27, 2018, 04:15:40 PM
OK we are trying to suppress RF noise and the capacitor does that, but it has to be able to stand up to the environment in which it finds itself. All mains systems suffer from voltage spikes. Either back EMF from other devices or noise on the transmission lines caused by network switching or lightening for instance.
The chosen capacitor needs to withstand these spikes, but the fact is that actually they don't. There is usually a breakdown of the insulation that vaporises a tiny bit of the metalisation that forms the plates. Insurance rated capacitors like these ones have to have self extinguishing insulation and a 'self healing' characteristic whereby the capacitor continues to function but at a slightly reduced capacitance. Apparently on average equipment sees 18 of these spikes every day :bugeye:
A bit about it here:
Post by: awemawson on June 28, 2018, 10:26:15 AM
Firstly - definite mains isolation - this thing takes no prisoners with high voltage DC - so not only turned off but unplugged as well. I was surprised to see that the front control panel hinge pins are self tappers - seems crude.
Then it was just a case of marking anything that might confuse on re-assembly, and un-bolting and un-screwing everything until finally the board could be removed from the power semiconductors that it mounts on
Post by: awemawson on June 28, 2018, 10:36:47 AM
The gunge that escaped took a devil of a lot of cleaning. Carburettor cleaner, and IPA didn't touch it. It was slightly soluble in acetone with vigerous rubbing so that's what I used.
So, cleaned up, repopulated, bolted back in and tested with the power on. It goes to the ready state as it did before, but this is no real proof that it's functional - just that it's not dead !
Anyway then I was dragged away to unload a pallet from a lorry. All those problems the other week with my hydrovane showed me how vulnerable I am to loss of compressed air - so this one, a three phase '502' on a 90 litre tank , was liberated from eBay and travelled down from Norwich - best go and test it's OK
Post by: PekkaNF on June 29, 2018, 03:55:46 AM
How do those MOV:s feel?
Post by: awemawson on June 29, 2018, 04:20:28 AM
The MOV's don't seem to have suffered.
I received a text this morning from the chap who used to operate this lathe telling me that there was an issue changing to low gear which they never got round to fixing, and if run in high gear for too long 'something in the back got very hot and had to be left to cool'
Now the 'something' can only really have been the KTK Mentor spindle drive so maybe those poor RFI suppression capacitors died from heat stroke :scratch:
Post by: Pete. on June 29, 2018, 03:29:57 PM
Post by: awemawson on June 29, 2018, 04:58:05 PM
Post by: vtsteam on June 29, 2018, 07:01:42 PM
Post by: awemawson on June 30, 2018, 06:11:54 AM
Main DC DRIVE motor by Mawdsleys 26.5 kW / 5000 RPM with attached blower motor. Drive goes (I assume, not dismantled yet) by drive belt in a big cover to the co-axial gear box by Andantex. This gear box has a lump bolted on the side with a Parvalux style 90 degree motor that I assume moves the gear box from one ratio to the other.
The gearbox label is not very clear where the ratio has been stamped, but I am reading that as "1 & 3.2" which seems sensible - straight through = 1, and via presumably a planetary system giving the 3.2
It seems that Andantex are still in business however nothing is showing up for this particular gear box. Looking at the 'type' box where it is stamped "BVR 353" implies it's a special for Beaver, but probably a variant of a standard one - possibly the gear change arrangement was customised.
Looking at note that I have for commissioning a later TC-20 lathe there would seem to be two 'M Codes' involved 'M41 - Low Gear Request' and 'M42 - High Gear Request'
I would suspect that if there is a gear changing problem it most likely is with the Parvalux motor and it's electrical drive system so long as the main box hasn't been mangled by changing gear 'on the fly', and the ladder logic in the controller should prevent this (hence 'Low Gear REQUEST' rather than 'Low Gear')
. . . again time only will tell.
What I can't find at the moment is the spindle encoder - this lathe has a 'C' axis whereby the spindle can be orientated anywhere in the 360 degrees of rotation for operations using 'live / driven tooling' in the tool turret
I am negotiating with someone who claims to have all the wiring diagrams for this vintage of TC-20, and I'm loath to replace the controller and power up things like the main drive and gear change system until I've given the drawings a meticulous inspection. He's been on holiday returning Monday so hopefully . . . .
Post by: awemawson on June 30, 2018, 07:16:51 AM
Post by: awemawson on June 30, 2018, 12:42:55 PM
Visually it's the same, the dimensions tally, but the ratio is different as mine is 1:3.2 whereas the standard is either 1:1.38 or 1:4.94 and the gear changing arrangement is different.
Now the model size is '353' and the data plate quotes 'BVR 353' - so a few customised tweaks for Beaver I think :clap:
Post by: vtsteam on June 30, 2018, 01:00:41 PM
Post by: awemawson on June 30, 2018, 05:17:18 PM
I was puzzled by the gear changing motor, as the bit of the label that I could see (upside down) implied that it was a single phase motor - but I've traced it's cable back to a standard interlocked pair of contactors wired for three phase reversing operation as I'd expect - but not with a single phase motor :scratch:
I managed to stick my iPhone into a place where I could get a decent picture - and all is revealed
It can work single phase with a 4 uF capacitor or 3 phase !
Post by: awemawson on July 02, 2018, 09:35:06 AM
First Quandary: They seem to be wired in parallel - this isn't good practise as being regulated they will be bound to be trying to achieve slightly different voltages - although equipped with remote sensing inputs, these are directly wired to the PSU's output terminals hence not used. The effect will be one power supply taking a larger share of the load than the other.
Second Quandary: The -ve output cable is numbered '102' and the +ve output is labelled '100' - cable '100' doesn't feature anywhere else on the machine (*) and +24 volts on this machine is cable '103' - OK a simple wire labelling error - careful tracking proved it should be labelled '103'
Third Quandary : and this is the BIG one. With no load the pair of PSU's deliver 24.2 volts, but on load this rises to 33 volts :bugeye: It was this strangeness that got me hunting in this area in the first place. Now at the moment the 24 volt rail is only being used for relays etc which won't have too much of a problem with the over voltage, BUT also the Baldor SMCC microprocessor card that manages the turret movements for tool changing runs off this 24 volts and had lights flashing all over the place when the fault was on - I hope it hasn't damaged it.
I could reproduce the fault with a 10 ohm load resistor as I disconnected the PSU's one by one in situ - the left hand one was U/S, the right hand one seems OK
Removing one PSU for testing the Baldor card seems to have calmed down now it only has 24.2 volts attacking it from the remaining PSU, and it's green ready light is coming on - so fingers crossed.
Bench testing I loaded the faulty one with a 48 watt 24 volt lorry bulb (actually a spare from my Startrite Bandsaw!) so drawing about 2 amps, and sure enough the output rose to 33 volts!. Simple transformer, twin diode rectifier and big electrolytic capacitor produces about 35 volts. There is a series pass regulator comprising three 2N3055 power Transistors with load sharing resistors in the Emitter circuit, and this group of three is driven by a fourth 2N3055 making a 'super alpha pair' (well quad in this case!). The base of the fourth 2N3055 is driven by a UA723CN voltage regulator IC
I suspect the 723 chip, but equally it could be one of the 2N3055's breaking down - I was amazed to find I have neither in stock - used to have masses of these things !
Although I've ordered some components, and I will repair this PSU, I am going to replace the pair of Kayser 24 volt 7.2 amp supplies with a single switch mode supply rated at 20.8 amps - over rated so it will be under run - which eBay has provided.
(* not quite true as alarmingly the three phase 415 volt input cable to the KTK Mentor Spindle Drive are labelled 100, 101, & 102 - some draughtman made what could have proved a expensive error )
Post by: vtsteam on July 02, 2018, 02:24:45 PM
Post by: awemawson on July 02, 2018, 03:33:04 PM
Being a bit OCD I'm going through everything with a fine toothed comb, firstly to try and understand what I've got and secondly to try and iron out as many of the issues as possible before the controller goes back in. When that starts taking control of hugely powerful X and Z axis servos, to say nothing of the 26.5 kW spindle motor I want peace and quiet to reign and minimise that nasty expensive bangs !
There are still areas on the machine I've not been able to access. There is a curious set of 'lazy susan' type linked bars behind the tail stock under covers that just let me a slight glimpse of them - I suspect that they support the swarf covers but I can't get in to see properly.
I'd like to be able to remove all the swarf covers but I don't think it's feasible. There is evidence of a bit of rust under the moving carriage but I can't get at it to clean it up, and it's not nice to move the carriage to do so. I have been manually triggering the automatic oiling system so areas like this are at least lubricated before thing moved.
Progress on the wiring diagrams - they are being scanned to .PDFs and expected in a day or two :thumbup:
Post by: awemawson on July 02, 2018, 04:20:37 PM
The actual ball screw is coupled via a toothed belt drive to the servo motor - I'l try and get time tomorrow to remove it's cover and probably have to fabricate something to engage one of the pulleys
Post by: nrml on July 02, 2018, 04:42:21 PM
To be honest, I don't understand a lot of what you are doing but that doesn't diminish my interest in the slightest. This is truly a worthy sequel to the Traub epic.
Post by: PK on July 02, 2018, 06:42:32 PM
There is a series pass regulator comprising three 2N3055 power Transistors with load sharing resistors in the Emitter circuit, and this group of three is driven by a fourth 2N3055 making a 'super alpha pair' (well quad in this case!). The base of the fourth 2N3055 is driven by a UA723CN voltage regulator ICWhat vintage is this machine Andrew?
I can remember building power supplies like that 30 years ago, and they were a little dated then.....
Post by: awemawson on July 03, 2018, 01:35:22 AM
Post by: awemawson on July 03, 2018, 03:32:00 AM
Then grasping the pulley I moved the carriage to it's extreme travel towards the tail stock, revealing the expected rust under the moving element. Nothing major, and a bit of judicious scraping and stoning and it will be fine. No doubt when I move it back towards the head stock end more will be revealed.
I need to clean up the ball screw as it also has suffered - again nothing major but it needs cleaning,
. . . quite a pleasing start to the day - now off to do some fencing !
Post by: awemawson on July 03, 2018, 07:38:35 AM
Meanwhile Angie the MyHermes courier turned up with the transformer that Pete Rimmer has kindly found for me - goes in a treat. I need to make a mounting plate and then it can be wired up, possibly this afternoon :scratch:
Many thanks Pete
Post by: awemawson on July 03, 2018, 02:29:37 PM
No mechanical problems but oh boy what a pain wiring it up. This transformer is taking 415 volts single phase from two of the three phases driving the cooling fan for the spindle motor. It's DIN rail terminals are right at the bottom of the cabinet and not big enough to safely take the third 'bootlace ferrule' - three as there is the motor, a suppressor network, and this extra terminal where I'm pinching 415 volts . I ended up removing the boot lace ferrules and soldering the wires before putting them in the DIN terminals - took ages to sort out as immediately behind this bit of the cabinet is the Fanuc Wire Eroder so space is very limited.
All works so a big thank you to Pete for the transformer
Post by: awemawson on July 04, 2018, 04:49:35 AM
Yesterday while rolling on the floor having difficulty getting those wires into DIN terminals, I'd managed to kick the screw lid of my bottle of Hellermann Hellerine Sleeving Oil that you use to slip Hellermann sleeves onto wires. I heard it go, it went skidding across the floor, but no way could I find it :(
So this morning, first task after pig mucking out, find that cap. Well opening the roller shutter door to get more light on the scene there it was, hiding under the spindle motor drive belt guard :thumbup:
. . . . but, putting my head down there i noticed a horribly blocked and apparently inaccessible air input filter on the intake for the spindle motor cooling fan 'snail'. Well no not inaccessible, there's yet another unbolt-able panel allowing me to remove and replace the filter. I'd thought that the airflow was a bit sluggish !
The filter comprises polyester fibre formed into an open felt, trapped between a pair of weld-mesh sheets and it just so happened that I had most of a roll of this stuff left over from when I rebuilt the Fanuc Tapecut Model M Wire EDM Machine (*)
Went in a treat and airflow is improved but frankly not fantastic
(* https://madmodder.net/index.php/topic,10085.0.html )
Post by: awemawson on July 04, 2018, 07:05:32 AM
Turned out to be two 2N3055's that were leaky Collector > Emitter - would be a nice simple fix, if it were not that of the two I pulled from the batch of ten that I had bought, one was dead short Collector > Emitter :bang: and it would have been EVEN simpler if I'd tested them BEFORE I soldered them in. No big deal but a bit confusing at the time.
Of course that meant that I had to go through the rest of the batch and test them before putting them in the 'stores' drawers.
I was rather surprised that Kayser only used a Mica insulator and no thermal paste between the 2N3055's and the case / heat sink. Being a linear PSU it does develop quite a bit of heat.
I'll leave it on soak test for the rest of the morning, but I will still go ahead and replace the pair of them with a switched mode one that is on order as it will run cooler (hopefully!)
Post by: awemawson on July 04, 2018, 07:17:21 AM
I am surprised that you don't have an industrial grade bore-scope in your box of toys. It would make inspection of these tight spaces much easier and i-phone dangling unnecessary.
To be honest, I don't understand a lot of what you are doing but that doesn't diminish my interest in the slightest. This is truly a worthy sequel to the Traub epic.
NRML,
I did at one time try to find a good one, but they all seemed very low resolution, but that was some years ago - I'm open to recommendations if anyone knows of a 'workable' one of reasonable resolution and price
Post by: charadam on July 04, 2018, 08:19:43 AM
I bought one of these a couple of years back. It feeds to a laptop, so although resolution is not exactly crisp, it has done eveything from tracing cable routes in the house to reading labels on my Chipmaster lathe motor. It also reassured me about the condition of the bore of my Brown Bess.
And, its only a few squid!
https://www.ebay.co.uk/itm/Waterproof-2M-USB-Endoscope-Borescope-Inspection-HD-Camera-for-Android-Phone/222599632400?epid=1677185312&hash=item33d3f8d610:g:A78AAOSwutFZgHI3
Post by: awemawson on July 04, 2018, 08:25:07 AM
Post by: awemawson on July 05, 2018, 10:11:21 AM
Well I totally FAILED :bang:
If you look at the first picture, the big panel "A" is flapping about unfixed at it's right hand (outer) edge, and is fixed to panel "B" and panel "C" with socket head cap screws into welded in nuts on the flange, screws having entered from the front of the lathe.
Panel "B" that looks as though it should just come out, has no fixings up or down, but is fixed to panel "A" as mentioned and to the cream main body of the machine similarly.
Panel "C" is L shaped with a return angle - again no up fixings only fixed to panel A and the cream body of the machine.
Now all these cap headed screw are totally inaccessible unless your arms are quadruple jointed and ten foot long - mine aren't !
I tried hand cranking the main carriage by turning the ball screw pulley as far as I dared (look how close that drill is to the wall of the enclosure :bugeye:) hoping something would be revealed - well it wasn't :bang:
Taking the pictures and studying them is slowly drawing me to the conclusion that the only way to get at them, is to somehow release the way covers at the tail stock end - slide them to the left and then just perhaps it might be possible to reach through, though I suspect I'm going to have to find how to move the tail stock itself out of the way - no idea how that happens - there's a crank handle, some locking cylinders and a big ram (but I think that the ram only moves the quill :scratch:)
Anyway the good thing to come out of this, is that the box ways and ballscrew on the far side of the carriage are in good shape as are the swarf covers :thumbup:
Post by: awemawson on July 05, 2018, 10:30:30 AM
Post by: awemawson on July 06, 2018, 07:12:28 AM
Post by: awemawson on July 06, 2018, 07:23:05 AM
OK panel off and guess what - hex headed button cap screws revealed - OK a long way away . . .if only I had a 30" long x 4 mm hex allen key. Well go make one my man :clap:
A bit of 8 mm rod drilled 4.4 mm one end and a 4 mm stub of allen key silver soldered in, and a Tee handle formed on the other end - worked a treat and guess what - panels "A" and "B" are now OFF :clap:
Panel "C" just has one cap screw left and is supported on wooden blocks - BUT looking again at the tailstock end of the lathe, that sloping panel unbolts and will I'm sure let me get Panel "C" off at last - but just now it's far too hot and sticky to continue !
I have a feeling that I'm going to re-design how these panels fix - maybe something along the lines of keyhole slots or maybe rare earth magnets :scratch:
Post by: PekkaNF on July 06, 2018, 07:46:21 AM
.....
I have a feeling that I'm going to re-design how these panels fix - maybe something along the lines of keyhole slots or maybe rare earth magnets :scratch:
Keyholes, slots or such locating features gets my vote every time. Too much slop or vibration? O-rings, NBR sealing strip or two sided foam tape (particulary god stuff, holds parts well, but comes appart with a little yank).
Magnets are good for a location where you need a repeatable force to actuate, but they are magnets really for any swarf etc. and really a nuisance magnetizing tools, instruments etc.
Pekka
Post by: WeldingRod on July 06, 2018, 08:13:04 AM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on July 06, 2018, 08:17:26 AM
Weldingrod - yes the Dzus fixing are good - not sure I'd be able to retrofit them but definitely one to bear in mind.
Well it was only another six cap heads to remove that sloping panel, so off it came revealing . . . . . well not a lot! A bit of square ducting, where is the cap head? No way I could see it, but groping about I could feel it, and just about get an allen key to it, and eventually off it came releasing panel "C"
. . . .now why did I want these panels off :scratch: :scratch:
Post by: WeldingRod on July 06, 2018, 01:16:34 PM
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Post by: PekkaNF on July 06, 2018, 03:17:04 PM
I suggest Dzus quarter turn fasteners. They are spring loaded, easy to use, and vibration resistant.
Sent from my SAMSUNG-SM-G891A using Tapatalk
Those are good, if you have an easy access to them and you can plan them. Andrew here has some locations at the in accesible end of the panel.
Pekka
Post by: AdeV on July 06, 2018, 03:49:21 PM
I have a feeling that I'm going to re-design how these panels fix - maybe something along the lines of keyhole slots or maybe rare earth magnets :scratch:
Industrial Velcro. No... seriously... that stuff is insanely grippy. To the point where, usually, an attempt to disconnect two parts results in the glue giving up & the velcro still stuck together! It should be OK on a big flat metal sheet though, especially if you supplement the sticky back with some superglue or something similarly grippy. A couple of self tappers maybe...
Post by: WeldingRod on July 06, 2018, 04:26:32 PM
They make metal velcro too. Some washing machines were assembled with it. Limited number of uses, though.
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: russ57 on July 07, 2018, 01:18:23 AM
Available on special order, only £852.05
(plus tax)...
I recall an early high speed laser printer, special tools included a Philips screwdriver, only $50, plus a box of 12 toner plastic catch bottles only $120..(forget the printer model but the controller was type HP3000)
Russ
Post by: awemawson on July 07, 2018, 07:13:52 AM
Firstly I needed to remove the tools from the Baruffaldi turret. Now I hadn't expected to be able to remove the ones round the back - normally you would rotate the tool to be removed to the forward position, and unscrew it's locking rack, but I can't yet rotate the turret. However, unlike the Sauter turret on the Traub lathe on this one there is actually just room to the rear to access the hex socket with an allen key - OK tools all removed.
Then extremely gentle and careful application of a wire brush, desperately trying to avoid the lips of the wipers, followed by 220 grit silicon carbide paper with WD40 and lots of elbow grease gave quite a decent result. I'm not sure if the WD40 or my perspiration gave a better result :clap:
I might just point out that most of this activity entailed me clambering inside the lathe :bugeye: While in there I noticed that behind and above the tool turret was packed with PTFE swarf - a good half bucket full !
Then the chuck - well I certainly don't want to force any abrasives into it but it needed something doing. I used the same method as the guards but with even more caution. When the hydraulics are all commissioned I will be able to remove the chuck for a proper strip down and clean, but in the mean time at least the brown rust is no more.
Post by: hermetic on July 07, 2018, 12:04:13 PM
Phil.
Post by: awemawson on July 07, 2018, 12:39:12 PM
Clean clothes called for this afternoon as guests arriving, so as an exercise I drew up a 3D model of a 'blanking plug' for the Tool Turret. In an ideal world I would have blanked of each open hole before using the wire brush, but had no blanking plugs. They seem astronomically priced at about £30 each - so my Cetus 3D printer is cranking one out as I type.
It's an interesting tool clamping system. The 40 mm diameter spigot has a rack of 4 mm pitch cut into it. The spigot enters the hole in the tool turret, and as you rotate the 8 mm hex locking key, an internal rack advances and engages the spigot pulling it tightly against the reference flat on the tool turret. There is a dowel to ensure alignment, and a pick up for 'through coolant'. System seems to work quite well.
Post by: awemawson on July 07, 2018, 03:15:34 PM
It was mainly baked on coolant, but the odd spot of rust. Fine wire wool and neat IPA shifted most of it, followed by 1800 grit silicon carbide paper and WD40 - came up as perfectly serviceable :thumbup:
. . . the 3D printer - oh yes - it still has 90 minutes to go but looking good
Post by: nrml on July 08, 2018, 06:42:18 AM
Post by: awemawson on July 08, 2018, 06:44:18 AM
Never mind, nothing a drill won't sort out ! Hole drilled and blanking plug fits nicely.
So this morning I re-worked the 3D model including the missing hole, and put a few chamfers here and there to tidy it up. Mk2 printing as I type :ddb:
Post by: awemawson on July 08, 2018, 06:52:00 AM
I am getting the impression that compared to the Traub, this lathe is poorly designed as far as the ergonomics of serviceability and choice of some components (like powers supplies) goes. Is this merely related to the age of the machine or does it confirm the stereotypical ''superior German engineering'' myth?
Well NRML no I don't think that follows. As the Traub had been in much more recent use, I wasn't so concerned to access every nook and cranny - believe me, it had it's idiosyncrasies. I never dismantled it mechanically to the extent that I have with the Beaver, and mechanically the Beaver is far more stoutly built. After all it is a significantly smaller lathe yet weighs 50% MORE than the Traub.
Don't forget the controller in this one IS German , and the poor placement of the battery with lack of forethought caused all those problems. And the twin paralleled up power supplies were made by a firm that was originally German .
Nowt wrong with British Engineering
Post by: awemawson on July 08, 2018, 10:05:54 AM
Came out OK, and fits which is the main point. I'll print one or two more but don't think that I need a full set twelve :scratch:
Post by: awemawson on July 08, 2018, 04:42:36 PM
So while waiting I investigated that mystery box on the rear of the contactor panel. A bit of stretching out and applying a 3 mm allen key and the L shaped panel came off - actually quite a weight, it's going to be fun aligning those screws on the way back !
As was expected there's a three phase transformer in there of a blooming big size - I'd hate to have to lift that into position on my own. But surprisingly there were also 'continental' fuses mounted down the side of it integral with the DIN rail terminals. Not the easiest place to get at to change fuses - mind everything also seems to have MCB breakers. (But I suspect that the transformer with the terminals and fuses is an off the shelf unit)
So the print software is predicting 13 hours before it's finished so I'll leave it to play over night
Post by: awemawson on July 09, 2018, 05:31:53 AM
Actually not too bad, as the other one came out fine. The mistake I made was not to turn on the heated platen ito improve adhesion. Two more printing, this time on a hot plate !
Meanwhile the postman brought an armful of parcels:
a/The replacement 24 volt 20.8 amp switch mode PSU, which I've put on soak test
b/ A 5 volt 5 amp switched mode PSU to replace the 78T05CT 3 amp 5 volt regulator that apparently is a regular failure on these lathes - also reduces the load on the 24 volt PSU by up to 3 amps
c/ Some DIN rail clips to mount the 24 volt PSU - it'll need an adaptor plate to pick up existing tapped holes in the PSU
d/ An extremely expensive Renishaw TP02S optical probe system
The original optical probe was a TP02 that had it's cylindrical battery within it's integral mounting spigot. The 'S' version take a standard PP3 version that can be changed without disturbing the probe mounting. This one has the 90 degree adaptor fitted, which I won't use - they just unscrew.
Bought 'sight unseen' my greatest fear was that it may have been left with a discharged battery within, (been there before) but my fears were unfounded. Yet to prove that it works. Information on the 'S' version seems a little sketchy (unless your Google Foo is better than mine . . . :clap:)
Post by: John Swift on July 09, 2018, 06:57:44 AM
I have been watching your latest epic CNC re build with great interest
how long are the leads to the 5V regulator ?
I have had problems in the past with spurious oscillations without a capacitor close to the regulators input terminals
how close to the maximum 35V limit is the regulator being run
( how high does the 24V supply go when lightly loaded or has inductive spikes added to its nominal 24V output )
running any semiconductor at its limit shortens it life
equipment with transformers designed for europe instead of the UK does not help
( In my part of the UK the single phase supply is 248V at times
and some european 220V devices don't last long )
John
Post by: RotarySMP on July 09, 2018, 10:06:01 AM
Mark
Post by: awemawson on July 09, 2018, 10:40:57 AM
Remember this cabinet is the one that they found necessary to equip retrospectively with a Vent Axia fan in the roof so it obviously ran hot. Replacing the three linear power supplies with two switch mode ones will dramatically cut down on the heat.
Admittedly I'm only soak testing the replacement 24 volt supply with a 48 watt bulb, but it's been on for several hours and isn't even warm to the touch. Same load on the repaired 24 volt supply and it was too hot to touch.
So all this time the twin plugs have been printing away and I've been shifting tons of earth round the back of the tractor shed. (*)
(* https://madmodder.net/index.php/topic,11819.msg150824.html#msg150824 )
Post by: awemawson on July 09, 2018, 05:11:22 PM
DIN rail cut to size and drilled for 3 off M4 screws and the back plate drilled and tapped. Then, clip on the new supplies and wire them up - simples. The 24 volt and mains wires are all original, I just re-terminated them with boot lace ferrules, so if it were necessary to re-fit the old supplies the wire lengths are still correct. The 5 volt from the new supply replacing the little 3 amp regulator is all new though.
Took an amazing time to do it all - about 3 1/2 hours !
Post by: awemawson on July 11, 2018, 05:20:08 AM
I've also received three faulty 'driven' tooling holders from a seller in the US. Advertised as seized but seeming to be the correct Baruffaldi fitting with the segmented drive dog, I thought that rebuilding them was a better prospect than building from scratch as I had intended.
I expect that the in line co-axial ones will have needle rollers and thrust races, whereas the right angled one will have bevel gear as well. Back burner job to investigate them as too much on my plate at the moment.
These things are horrendously expensive to buy new - the simple one are of the order of £1000 and the right angled ones at least £1500. Needless to say these were a very small fraction of that price - £150 - I thought that I'd better grab them as they flitted by as they are not the most common of items.
Post by: awemawson on July 12, 2018, 04:10:10 AM
Massive earths went back first - at least they will tether it if it has a desire to plunge off the shelf, then the mains input, then all the interface connectors. At the moment it's just pushed in unscrewed - I'll leave final screwing in until everything is working otherwise I reckon I'm pushing my luck.
While this was happening, Adrian the Parcel Force man delivered some DIN rail stop blocks. When I replaced those power supplies the day before yeaterday, I'd thought I had some but no, wrong again. Well I have now :ddb:
So stop blocks fitted to stop the PSU's sliding along the rail in case we get a sudden gravity surge. Actually, it's quite easy when working in a cabinet, to accidentally move something and stretch cables - been there - done that - now fit stop blocks :ddb:
Post by: awemawson on July 12, 2018, 04:26:36 AM
OK Press the Emergency Stop Button in, hold your breath, press controller start. No dramas but loads of error messages. The NC (Numeric Controller - part of the Sinumerik 820T) is reporting X-Axis and Z-Axis working area limits.
The PLC (Programmable Logic Controller - part of the Sinumerik 820T) is reporting all sorts of errors most of which can be accounted for by the fact that the NC won't go 'Ready'. When 'Ready' the NC outputs a digital output that enables several relays that supply power to the Hydraulic Pump, and Spindle and Axis Drives, and also a '24 volts OK' relay which drives an input to the controller. The 24 volts IS OK but the monitoring mechanism isn't powered up !
A bit of furtling about produced details of how to set the working area up, and that cleared the two Working Area Limit errors.
However the state of play at the moment is that the NC remains in 'Emergency Stop' (Yes the E-Stop button HAS been released!) and I need to find out what it's missing to go 'ready'
Post by: vtsteam on July 12, 2018, 01:16:25 PM
Limit switches?
Post by: awemawson on July 12, 2018, 04:17:47 PM
Even odder, the output that signifies 'Control Ready' is most definitely not 'true' it's at 0 volts at the point it's supposed to drive a relay . BUT poking about in the PLC "Q" bits which are outputs, it IS logical true. Without it coming to the outside world, the E-Stop button is ignored.
It's possible the output card has popped but I wasn't able to investigate any further today as I had to change the main hydraulic pump on the digger - it's in now but I probably have 5 hours work with it tomorrow shifting earth before the weather breaks. Also guests for super and two sets of cottage guests arriving, so not much play time on Friday.
Post by: awemawson on July 14, 2018, 11:49:20 AM
Trying to make sense of the circuit diagram that I have I firstly went round each relay and contactor on the panel matching it's wire numbers to the diagram and sticking a label on when I'd identified it's function - trouble is they don't differentiate between relays and contactors which is confusing as often you get a relay driving a contactor :bang:
All this so I could bottom out what initially looked to be a trivial circuit monitoring the 24 volt rail. Two relay's 'CR10' and 'CR20' which ACCORDING TO THE CIRCUIT each had their coils across the 24 volt rail, and each had a normally open contact in series with each other and connecting a digital input to 24 volts. How simple is that ?
Well actually a bit complex as 'CR10' isn't connected to '0 volts' but to the overload trip circuit for several motor contactors, and 'CR20' derives its '24 volts' from the digital output 'NC Ready' and it is this very signal NC Ready that is in the wrong state and keeping E-Stop asserted :bang:
So OK lets go round the 'NC Ready loop' a few times until dizzy. If I look at the logical bit for NC Ready in the PLC 'Q' word the relevant bit IS set but not physically set to the outside world.
If I trot along signals from the same input / output card that DO have bits at 'logic 1 (24 volts)' I can also see the relevant bit in the appropriate 'Q' word. Now the PLC documentation implies (but doesn't explicitly say) that a bit set in the Q word appears as an output. Now I am aware that some manufacturers have a further logical step between the register data (Q word equiv) and driving an output - the Mitsubishi in the Traub did this, but I've not found any mention of it with the Siemens Sinumerik controllers.
So what are we left with :scratch: Well it could be a further internal logical step, or it could be that that particular output on this I/O card is faulty. I think that the later is the most likely but time only will tell.
I could exchange the two I/O cards that I have and see if the fault moves, but it's an utter pain removing the I/O rack as it involves pulling the controller and the Operators panel out - and if the fault DOES move it'll all have to be done a second time once a replacement is found. OR I could source a replacement on spec, swap it in, and if that proves to have been the fault no more fiddling about. If it doesn't then at least I have a 'shelf spare'
This course of action probably sounds rather spendthrift - BUT there are loads of these cards 'tested good' on eBay in Germany for £15 each so I've ordered one.
According to the Siemens book of words on the PLC it is possible to write into the Q word bits to generate output, so I chose an unused output, wrote to the Q word and measured no output, but when I looked again at the Q word it was back to before I wrote to it. I suspect that the PLC program is cycling round writing it's wanted outputs so if I change anything it is promptly changed back 5 milliseconds later :bang: I'm sure that there is a way of stopping the PLC program running, but then I'm not sure whether anything would be output :scratch:
Post by: awemawson on July 14, 2018, 02:33:59 PM
I decided to 'bell out' the core in the cable that represents 'NC Ready' - this involved pulling the 34 way IDC plug from the rear (and most inaccessible) I/O card. Cable belled out OK, but when I tried to put the plug back - this is an entirely 'by feel' operation, I managed to bend a pin on the card :bang:
Now after a few cusses I decided that I might as well dismantle the I/O Rack using keyhole surgery though the aperture that holds the control panel. Just possible but it hurts your wrists :(
Well doing it I thought that I might as well swap the pair of I/O cards and see if the fault moves - IT DID :clap:
So now we have 'NC Ready' coming true, and the E-Stop button does things - naturally there are other errors but at least this particular mystery is solved and my hunch about the card being faulty is proven correct - as I said earlier, I've ordered one (well actually two !) so PROGRESS !!
Post by: vtsteam on July 14, 2018, 10:09:15 PM
Amazing how much reverse engineering you have to do, even with manuals for these things. You wonder, is it a faulty component, or is the manual accurate, or are both the problem? Then if you do something and get the green light it's like Christmas! Except, on to the next.... anyway: :clap: :thumbup: :beer:
Post by: awemawson on July 15, 2018, 05:26:13 AM
The one on the left is monitoring the overload trip circuits for various motors, and the one on the right is NC-READY ! - relays suitably labelled. But the controller is still reporting a 24 volt psu problem and I have no idea how it is monitoring it :scratch: The relays shown on the diagram as CR10 and CR20 are nowhere to be found and I did eventually find the correct bit of the diagram showing the Overload and NC Ready relays.
Oh well maybe they will turn up somewhere else but I thought that I'd been everywhere by now in the mammoth structure of a lathe !
(* Tempo 200EP Inductive wire tracer intended for telecomms use)
Post by: awemawson on July 15, 2018, 05:50:35 AM
The only places left were the hydraulic cabinets for the tailstock and chuck - and on their control cards we have - CR10 and CR20 - hoo blooming ray :ddb:
The odd thing is that they both have tell tail green LEDs which are glowing away merrily when the power in on, but at least now I have a further avenue of investigation to follow :thumbup:
. . have to stop now as entertaining for lunch and need to be presentable :scratch:
Post by: awemawson on July 15, 2018, 11:53:01 AM
Chasing now I know where the relays are, it turns out that CR10's contact is working, but CR20 - either the relay or the wiring is duff. I have temporarily wired round it, and guess what - things started happening.
She's ALIVE
I could jog the Z axis up and down as I wished. Initially the X axis moved a fraction then something tripped - repeatable problem - I thought that perhaps it was on the limit switches, and wanted to remove the cover from the servo motor / ball screw drive to wind it by hand, but it was in an inaccessible place too close to the tail stock. But - hey - I can JOG Z where I want it. So the saddle was trundled down the ways giving access to the belt cover.
Cover off revealed the expected drive belt and pulleys and what I had forgotten - the X axis brake unit. As the X axis is tilted up at a step angle, without a brake, and with low friction ball screws, it will descend under it's own weight. I checked the current though the brake coil (0.6 amps) with my clamp on ammeter - no way can I turn the pulleys, and I dare not remove the brake or the X axis will plunge.
Well it looked a bit grotty with surface rust - perhaps the plates are rusted together. A few gentle taps with a plastic mallet, and guess what - X now moves as it should. As you jog it's slightly disconcerting hearing the loud 'click' as the brake comes off, and on again when motion ceases. (Brake is spring loaded ON with no power)
SO - I was able to move X & Z to their home / reference positions to make the controller happy, and was just starting initialising the Tool Turret when there was an almighty :zap: BANG :zap: and the workshop filled with acrid smoke - it still stinks as I type this .
I leapt to the main switch to kill the power - smoke was pouring out from below the KTK Mentor main spindle drive. Closer inspection (holding my breath) showed that in fact it was coming from the Field Coil Controller which is mounted below the Spindle Drive, and the culprit was one of those 0.1 uF 500 volt AC RFI suppressor capacitors, identical to the ones I replaced on the Mentor drive. Luckily I still have some left over.
Oh boy it made a loud bang and a huge volume of smoke - fortunately due to the hot weather I had my roller shutter door open and fans blowing. Knowing how hard it was to clean the mess off the Mentor board, I quickly set to with some IPA to try and clean the mess off the grey trunking - no way was it shifting, and I can see globules of molten solder have embedded themselves in various places.
However I am a happy bunny - this is a major milestone passed. OK I need to bottom the CR20 relay problem, I still need to replace that I/O card, and no doubt there will be a few more 'issues' along the way. I've not yet got the Main Spindle turning under power, nor the drive for Powered Tooling.
. . . but satisfying . . . :ddb:
Post by: awemawson on July 15, 2018, 01:58:11 PM
It all went ok - capacitors replaced and now I can jog X & Z, I can send the X & Z axis to their reference points, and I can jog the spindle. What I can't do at the moment is initialise the Tool Turret - it's asking me to do it but the format of the command is eluding me at the moment.
Post by: russ57 on July 16, 2018, 04:11:29 AM
Russ
Post by: awemawson on July 16, 2018, 05:24:09 AM
I started the day determined to bottom out that 24 volt monitoring relay issue that I linked out temporarily. The way it works is that CR10 is located on a remote card in the Chuck hydraulic control cabinet, and has it's coil straight across 24 volts. It's normally open contact is brought back to the big control cabinet in the rear of the machine.
Similarly CR20 is located in the Tailstock hydraulic cabinet on a similar remote card with it's normally open contact brought to the rear of the machine.
These contacts are wired is series (according to the diagram!) the common point being 'Terminal 100' the other side of the CR10 contact is wired to 24 volts and the other side of the CR20 contact is wired to a digital input where the voltage is monitored.
Now I knew that Terminal 100 was at 24 volts (so the CR10 contact is closed and working) but the other side of the CR20 contact at the digital input was at 0 volts. I had just wired the digital input to 24 volts temporarily to get round the problem.
So - open up the Tailstock box and pull the card out to check the relay. The card is located on the common nylon PCB pegs - it pushes on and a barb pops sideways to lock the card in. Easy to remove by pressing the barb back - except that I couldn't get at them. OK there is actually a proper tool for this job, essentially just a suitable diameter tube that presses onto the peg and releases the PCB. No, I didn't have one, but I have a box of bar ends and a lathe, so yes now I do - made it SO much easier :ddb:
Then I gingerly powered up with the card free floating on it's wires and check the relay contact. Sure enough - closed powered up, open with no power. So if it's not the relay it must be the cable. Belled the cable out - no it doesn't go to Terminal 100 - it goes to Terminal 99 - and nothing else goes to terminal 99, it's all on it's lonesome doing nothing !
However, unlike the diagram, there are two extra wires on Terminal 100 that are not on the diagram, a Green and a Violet, so at some time I'm going to have to trace where they go. But I took a chance and moved the wire from 99 to 100, and guess what, it works. Now as it was the CR20 contact can never have been in circuit and it never worked - very very odd as I certainly haven't moved that wire :scratch:
OK knock that issue over (and created another mystery) so back to trying to initialise the Turret.
Later Edit: well of course I couldn't leave it at that so I chased those wires. The Green one goes into a cable form labelled 'Zero Ref' and the Violet one goes into a cable form labelled 'Position Switch' presumably providing power to these devices :scratch:
Post by: hermetic on July 16, 2018, 06:10:11 AM
Phil
Post by: awemawson on July 16, 2018, 10:59:23 AM
I spent some time trying to master the Siemens Sinumerik implementation of MDI - MDI being a way that you can give the machine a few manual commands to move or spin or change tools. It is also used to send initialisation codes to the Turret Controller (a Baldor SMCC 602090-102) which is a microprocessor controlled servo system looking after turret rotation, clamping etc.
The trouble was that I had initially miss-understood a command line in a crib sheet that I'd been given, and having entered it the machine (correctly as it was wrong) refused to run it, but I could find no way to delete the wrong information.
Much experimentation and button pressing and we are initialised.
So now I can jog all axis, select tools, start the spindle and it seems all systems are 'go' I've not actually yet found how to extend the tailstock ram or spin the powered tooling, but progress continues :thumbup:
Post by: vtsteam on July 16, 2018, 11:16:53 PM
An you're moving right along today, with all axis moving. Good man! :beer:
Post by: awemawson on July 17, 2018, 11:22:27 AM
Last night I was experimenting with MDI and tool changes. I selected tool 10 and the machine did it's thing rotating the tool turret. It pushes the tool disk forward, rotates to location, then moves it back - I assume that there is a Hirth index disk (*) which it then precisely locates on. I then told it to select tool 5 (where we had been before) - it completed most of the move but failed to finish, and the tool disk looks to be 4 mm too far forwards, as the coolant pipe no longer reaches the port on the rear of the tool disk by that amount.
As a slight consolation I did get the tailstock moving out and back under program control !
So major investigation into the Turret. I removed as many covers as I could and managed to gain access to the internal terminal box where the 'position sensor' leads terminate - these are proximity sensors running off 24 volts (which is there) but oddly all four proximity sensors are saying 'no detect' - I'd have thought one or two would be active.
While climbing all over the turret I had opportunity to examine the Turret Crash damage that I'd known it had suffered in the past. Seems to be just to the tin work, and a bit of tin-smithing should sort it out.
Likewise the swarf cover above the turret was somewhat rusty so got cleaned up.
All a bit of a set back - but these things happen - I suspect I'm going to have to get at the inside workings of the turret - just not sure how yet :scratch:
(* Hirth Index disk looks like a flat bevel gear with teeth facing forward, and mates with another identical one in any of N discrete locations dependant on tooth count)
Post by: awemawson on July 18, 2018, 04:09:31 PM
I managed, by re-wiring hydraulic solenoids, to unlock the turret, allowing me to turn it manually and set it in the correct position, thus being able to initialise it - hooray. I could then select tools at will, jog where I wanted, and spin the spindle at great speeds forward and reverse.
However, once turned off and back on I couldn't even jog, the control reporting a fault with the KTK Mentor. Now I've been through EVERY wire into and out of the Mentor, documented them and inspected any that might report a fault. None do, and the drive says it's ready on it's front panel.
BUT - if the power to the Mentor is dropped and remade by dropping out it's isolator the fault very occasionally clears :scratch:
Once this fault is cleared I can jog as I wish. So two issues to bottom, the Mentor issue and the Turret issue - I did at least manage to winkle circuit diagrams for the Turret SMCC servo card out of Delta Tau in California today :thumbup:
I think tomorrow I will log the voltages on all 41 of the Mentors interface connections with the fault 'ON' and try to clear it and repeat the logging - hopefully that will show how the controller knows that there is a fault :scratch:
. . . meanwhile I'm going to finish off this bottle of Pinot, I'm sure things will look better after that :clap:
Post by: charadam on July 18, 2018, 05:13:56 PM
Is this normal for machines of this vintage?
I mean, apprentices in a cold shed throwing components from 5 yards and installing them where they fall?
Or is the component layout and circuitry designed with no concept of maintenance or fault finding.
Post by: awemawson on July 18, 2018, 05:51:13 PM
It's not untypical that one fixes something only to find another issue emerge. Hopefully as I progress and a few hours are put on the clock (which isn't working by the way !!!!) the reliability will increase.
Post by: awemawson on July 19, 2018, 03:31:51 PM
You may recall that when I pulled the turret apart, one of the complicated covers had suffered a collision with the tail stock when at the University. I was quite badly crumpled and unfortunately someone had welded up a crack on the corner while it was in the crumpled state. This of course makes a repair far more difficult.
I'd thought that with a good heating from my 'Rosebud' tip on the oxy-acetylene torch I could get most of the panel a dull red and tap in back with a hammer on the steel welding bench. No way :bang: I did manage to get the folds 'pointing in the right direction' so I decided to use the 60 ton press to flatten it. Worked quite well. I may well cut off the welded corner, and weld in a new folded piece - but I can't do that until the rest of the tin work is back to give me something to measure to.
Post by: awemawson on July 19, 2018, 03:48:56 PM
But before this I thought that the best approach was to try and decode the PLC 'ladder structure' to see what inputs lead to the generated error output. There is a software package that Siemens make available called 'Step 7' intended for generating PLC code and ladders but apparently also able to read the PLC code from an existing machine.
But no - you can't just down load it - you have to jump though all sorts of hoops and sign all sorts of disclaimers before you can down load it. The Siemens web site was a nightmare today - I had to reset my password five times as it kept locking my account. Eventually I spoke to a human being in Manchester who greased the path and expedited my 1.8 Gb download. That was finished at 13:08 today, and the self installing program has JUST finished seven and a half hours later - I don't have the energy to look at it yet :bang: (But I only have a 21 day free trial !!)
So, I don't know why but I pressed the 'Spindle Jog' button on the controller, and the main spindle motor growled but didn't turn. Ah I though either the armature or the field isn't energised, but one of them is ! I rigged up my Fluke clamp ammeter and repeated the experiment on both the armature (shows 50 amps DC) and the Field coils - zilch - nowt, nothing. So that reinforces the fact the issue is quite probably the FXM-3 - this is the little card below the KTK Mentor, on which that poor 0.1 uF capacitor committed Hari Kari the other day - so this is probably collateral damage.
So off to try and source a spare tomorrow
Post by: RotarySMP on July 20, 2018, 06:42:50 AM
Mark
Post by: awemawson on July 20, 2018, 08:07:10 AM
Qualified in Applied Physics. Employed for years running a support organisation for Process Control computers. Hobby mechanical engineering. Retired early and bought a small farm.
Easy really :lol:
Post by: PekkaNF on July 20, 2018, 01:41:14 PM
Simple I/O signal is possible to debug without commented program, but when it has plenty of internocks and sequences, it will become easily convoluted. Many alarms and interlocks are grouped toget as flags and those would be nice to have commented.
Pekka
Post by: awemawson on July 21, 2018, 04:58:23 PM
I've located a service exchange FXM-3 field coil drive card and agreed a price with the vendor but the weekend has got in the way.
Firstly, the Postman brought me a parcel from the USA - a spare Baldor SMCC card. This card is a servo card that drives the tool turret. I've been having problems re-initialising the turret and a working spare would help diagnosis - EXCEPT - the card delivered is not the card I bought ! I very carefully made sure that the vendors image exactly matched my card as there are apparently several variants. This one is missing an EEPROM, has an extra LED character display, and many option sockets that are not on mine.
As I understand it, when you initialise the turret by issuing an M80 command from the Sinumerik 820T is sends a load of data to the SMCC card which effectively is it's program. You then send a tool command to it that tells it which tool position is currently presented to synchronise both systems. This data that is sent I believe to be retained in the EEPROM.
With no documentation I'm not prepared to try it and a pained email has been sent to California asking pointed questions !
The turret position is read by the system by an internal Euchner four way proximity switch block, and on one occasion I did notice that one bit wasn't being read reliably, so I reset the gap and it now reads ok.
Under certain circumstances, and I've not discovered exactly what, the Turret will initialise, and once initialised seems fine for tool changes until you power off again. I then have to thrash about trying to re-initialise.
At one point, quite repeatably it was fine if the turret had to rotate clockwise, but failed if the required tool meant an anti-clockwise rotation. This lead to what was probably a red herring, the Simodrive AC servo system that drives the X,Y, and turret servo motors - more of that later.
Here are the two variants of SMCC that I now have
Post by: awemawson on July 21, 2018, 05:21:25 PM
So venturing into the Simodrive cabinet the aim was to identify card part numbers and google any setting up details that might be floating in the Ether.
Taking the front panel off you are faced with what at first looks to be a confusing mass of connectors and wires. As far as I can tell, there are two two channel servo cards for X, Y, T and an unused one, and three power amplifier boards. Centrally there is some sort of supervisory board, and below a Power Supply with a lethal pair of 275 volt DC buss bars.
Eventually I managed to extract one of the two channel servo cards for photography and identification. Unfortunately I can find no setting up data for this card - loads for sale but no documentation.
There is a daughter card facing forwards with a DIP switch bank of options and three twiddle pots per channel - I bet on of those is the offset null !
My first port of call was the Siemens support web site - for the 7th time in two days I had to reset my password - they have some very odd fault on that site ! No data on the servo card though.
So I put it all back together, had another session thrashing about trying to find a sequence that would re-initialise the Turret system, and then darn me it happily did tool changes in both directions as long as I wanted - still wouldn't survive a power off / on cycle so I left it for the night !
Post by: awemawson on July 22, 2018, 07:21:38 AM
The Turret has seven proximity switches. Four in a Euchner block as described above, one for 'Clamped', one for 'Unclamped' and one for 'Zero Reference'
I had been able to prove all working except the 'Zero Reference' one so this morning, moving the turret as far as I could towards the chuck without tripping the over travel alarm, I could just see it right at the top back surface, pointing inwards towards the toothed dog clutch disk. I don't like sticking my head in places like this with the power on, as if the Z servo was to have a fault I could be pulped, but the power has to be on to unclamp the turret to rotate it to see the notch it is supposed to detect. Strangely this corresponds to somewhere between tool positions 7 & 8
With my 'scope on the output of the sensor as detailed in the circuit diagram, I rotated the turret back and forth either side of the notch. Permanent 24 volts - nothing detected. Just to be sure, I took the cover off the terminal box mounted on the turret, checked that the sensor had it's 0v and 24v supplies, and it's output was permanent 24 v. OK faulty sensor - unscrew it. Well it's right behind the turret. By lowering the X axis as far as possible it's possible to start unscrewing it, hindered by the clamp and unclamp sensors whose cables get in the way.
Eventually, it's out on the bench for testing. Rough and ready - bench supply set to 24 volts, meter on the output, spanner in and out of range. Works perfectly :bang:
Actually, this is good thing as these particular proximity sensors are far from cheap, but whats going on. Back to the terminal block - hang on still showing 24 volts as in detecting :scratch: Then back to the other end of the cable where it goes into the SMCC card - why's that wire a different colour ???
Turns out that the output of the sensor has been connected to the famous 'Terminal 100' - it's the extra green wire that caused confusion before. All very odd.
I can see that the software doesn't need a Zero Ref input when it already has a four bit tool count as the tool disk rotates - so is this an official mod, or did someone bodge it in the past - no way of knowing
Can't put it back just yet as I need to smarten up - the wife's playing a gig in a pub this afternoon, and it would be rude not to support her - oh just by chance it's a Harvey's Beer pub - the only bitter worth drinking - not that I'm biased :ddb:
Post by: vtsteam on July 22, 2018, 10:01:53 AM
....
Permanent 24 volts - nothing detected. Just to be sure, I took the cover off the terminal box mounted on the turret, checked that the sensor had it's 0v and 24v supplies, and it's output was permanent 24 v. OK faulty sensor - unscrew it. ....
Isn't that inverted compared to your test?
Post by: vtsteam on July 22, 2018, 10:04:01 AM
Post by: PekkaNF on July 22, 2018, 11:17:51 AM
Pekka
Post by: awemawson on July 22, 2018, 01:18:07 PM
Would have saved so much time. When I put it back, even though it is obviously not in use, I'll use the tester to set it up so it can work should the need arise.
The wire connected to the output is held firmly at a nominal 24 volts DC - so no way the sensor will have any affect !
It's detecting (in the original concept I think) a notch in a very slow moving disk of steel, so I'd guess it's a simple induced magnetic one, but it bears no markings.
Post by: awemawson on July 22, 2018, 01:52:05 PM
....
Permanent 24 volts - nothing detected. Just to be sure, I took the cover off the terminal box mounted on the turret, checked that the sensor had it's 0v and 24v supplies, and it's output was permanent 24 v. OK faulty sensor - unscrew it. ....
Isn't that inverted compared to your test?
i was turning the turret back and forth across the notch where we should go from detected to nothing and back to detected. In practise of course nothing was detected as the sensor output was nobbled !
Post by: awemawson on July 23, 2018, 06:46:49 AM
I put the Index proximity sensor back. In order to start the thread on the device I had to unsheathe the other sensors to get the alignment right. Then I set it up using the little test box, and then got to wondering about the odd wiring. A multi-core cable takes the four outputs from the Euchner Tool Position Sensor directly to digital inputs. But it also provides 0 volts and 24 volts to the sensor and carries the Index transducer output to Terminal 100 on the Violet wire. Then from this terminal a green wire goes back to the SMCC card to it's Index input. Now this is illogical, as Terminal 100 is permanently at 24 volts when the system is 'up' due to the CR10 / CR20 'Volts Healthy' relays.
I reasoned that this is a cock up, and that the Violet Index output and the Green Index Input should have been joined using the adjacent terminal 99 so that a genuine Index signal is provided at one point in the rotation of the Turret Tool Disk due to the notch in the clutch disk in it's innards.
. . .so take your life in your hands and alter the wiring . . stop fussing :ddb:
Well I did, and do you know - since then the Turret has performed faultlessly :clap: :clap:
Now actually this is very odd, as that Index signal is usually at 24 volts, and when the Turret is initialised it doesn't rotate the tool disk so the Index signal will remain at 24 volts just as it would when it was connected to Terminal 100 :scratch:
But let's not get carried away, it works. It just might be with all the dismantling and reassembly I have made good a poor connection, but, fingers crossed, the Turret does what it is supposed to do :thumbup:
On the Spindle Motor Field Coil driver front, my chap has gone very quiet and is not answering texts or phone messages. I've actually ordered all the semiconductors on the board as a fall back solution, but would far rather have a known good service spare as had been offered. We'll see which arrives first. Certainly the component approach would be far less costly.
Post by: awemawson on July 23, 2018, 12:25:57 PM
Most of the pea bulbs had failed, and their heat had made the plastic of the sockets very fragile - I'd not been able to source replacement bulbs of a low enough wattage, and it turned out that the complete modern version with a red LED instead of a bulb was not much more than the non existent bulbs anyway.
There are ten hydraulic solenoid valves on this machine - handy as the tell tales come in five packs! So this afternoon I've installed the first five in the tail stock hydraulic cupboard.
Should make fault finding a bit easier - still five to go in the chuck control cupboard.
Post by: Pete. on July 23, 2018, 01:01:03 PM
Post by: PekkaNF on July 23, 2018, 03:20:00 PM
They were pretty cheap to use in a hurry.
This sort of thing:
https://canfieldconnector.wordpress.com/2016/06/10/ilw-interposed-lighted-wafer-indicator-light-2/
Replacing the connector in this case was better choicse ofcourse.
Pekka
Post by: awemawson on July 23, 2018, 04:40:54 PM
Well just as I thought I knew where everything is on the mammoth lathe I stumble across another three hydraulic solenoid valves lurking behind the headstock.
I think that these are for clamping and unclamping the chuck, but I thought I'd already found those :scratch:
Needs more exploring tomorrow - too late now
Post by: awemawson on July 24, 2018, 09:22:26 AM
Firstly I was actually contacted at last by the supplier of the replacement FXM-3 field coil driver for the main spindle motor telling me he'd 'sort it today' - this is a 'good thing' as although I've got most of the semiconductors to replace the lot lock stock and barrel I'd rather have a tested spare to save too much excitement
Secondly I replaced all the DIN 43650 solenoid sockets in the 'chuck hydraulic cupboard' and ordered some more for the ones I discovered hidden behind the headstock.
The exercise of replacing these sockets has demonstrated to me the importance of re-labelling all the cables used for these solenoids. Originally they were very clearly marked using wrap round printed labels, but time and handling combined no doubt with a bit of hydraulic oil have proved their undoing.
I intend to use cable ties with an attached 'write on flag' when I find suitably sized ones - you'd be amazed how many sellers omit the size of the write on bit, and only give the cable tie size in their adverts !
Post by: mc on July 24, 2018, 02:06:27 PM
If you don't mind me asking, how does the live tool dog engage with the tools?
Is it spring loaded, or does it rely on the servo running to ensure the dogs engage, when the turret retracts?
This is my weapon of choice for cable marking - http://www.labelzone.co.uk/brother-pt-e300vp-professional-handheld-label-printer/p15675
I generally use heatshrink for multi-core cables, and tape flags for smaller cables (or when I inevetiably forget to put the heatshrink label on...) plus it avoids any future problems trying to translate my handwriting!
Post by: awemawson on July 24, 2018, 05:15:50 PM
Now my turret is one made by Beaver themselves. Prior to this they were fitting Baruffaldi turrets, and seem to have copied the dog clutch pattern but not the length of the VDI40 shank projecting rearwards.
Power tooling is stupidly expensive - I have bought three genuine Baruffaldi ones that are seized solid and will have to rebuild them. Part of the re build will be to extend the dog clutch rearwards - but that's for the future - a few other things to sort out first.
BTW I'm going to use cable ties with flags to avoid having to disconnect all the cables again. I have a CTK 'brander' that has type wheels that you rotate to spell what you want to say in (I think) 8 or 10 characters, I dug it out to try it this afternoon but the type wheels that I have don't include the letters that I need. It has a heating element inside the type wheels and a wide ribbon of coloured plastic film. The film gets embossed into the cable sheath.
Post by: awemawson on July 25, 2018, 06:36:33 AM
Well the answer came along with a hot flush - these are PRESSURE SWITCHES not solenoid valves :bang: My excuse for this plonker moment is that they are in a dark inaccessible corner.
. . . off came the ones I'd done, and back on went the originals, and I crawled away to give my pride time to heal :lol:
The good news is that yesterday I obtained the Beaver Manual for this lathe, and also the detailed manual for the SMCC card as PDF's. The Beaver manual is not hugely informative, and unfortunately the drawings of the turret are for the Baruffaldi version, but never mind there is some useful stuff in there.
Post by: awemawson on July 26, 2018, 02:12:57 PM
I think that maybe the issues I was having with the turret were caused by stiff oil seals - with a bit of use it seems to be getting better. I still can't drive the spindle as the field coil current driver hasn't arrived yet.
Not sure why I'm getting that 'fish eye' distortion, I've probably set the GoPro up wrong, I've not used it in over a year.
Post by: mc on July 26, 2018, 05:22:32 PM
GoPro's do give a fisheye effect, it's just the way they are.
Thanks for the info about the turret. I've got an idea brewing, that involves something a bit bigger than my Denford Cyclone, but still fitting under the existing roof of my workshop, as I make some parts that would really benefit from a lathe with live tooling. Just need to get another couple major projects done and running first.
Post by: awemawson on July 26, 2018, 05:49:37 PM
Post by: awemawson on July 27, 2018, 06:43:12 AM
Useful exercise, as I unearthed another pressure switch that I had treated as a solenoid, so that's probably saved a few hours of fault finding !
Post by: WeldingRod on July 27, 2018, 10:46:26 AM
They also make ones with two lights for switches.
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on July 27, 2018, 10:53:33 AM
During testing I've set the maximum field voltage to a conservative 100 as the spindle will see no machining load until everything else is sorted. Field current is proportional to torque as I understand it.
:ddb: :ddb: Anyway - we now have a spinning spindle :ddb: :ddb:
Post by: awemawson on July 28, 2018, 06:27:55 AM
Nothing so simple as a 'destructive backspace' key to delete characters - there is a complicated sequence you have to go through, which is now printed out and magnetically attached to the cabinet until I've learnt it :bang:
It also seems that programs that are deleted still take up memory, and you have to run some sort of sorting routine on what's stored to release the unused bytes - but that's for later - got to go to a BBQ now - it's hard life. :clap:
This morning I was experimenting with 'feed per rev' - G96 on this machine - whereby the machine alters the spindle RPM to keep the surface cutting speed constant. It was doing this when the need for 'backspace delete' became apparent :palm:
Post by: awemawson on July 29, 2018, 12:52:33 PM
So today I've been having fans pointing at things and trying in vain to locate the issue, until . . .
. . . the fault came on, and I happened to read the data word on the controller that indicates tool position, and blow me the least significant bit was missing! Now there is a four way proximity switch in the turret that I'd looked at before and all seemed well, but while the fault was on I was able to chase the wiring and the issue was definitely the proximity sensor - so pull it out. Shame really as having been in here before I'd already sealed the chamber with Blue Hy-Lo-Mar sealant.
Out it came and certainly bit zero is different from the others. Unloaded it's giving about 7 volts not detecting, but goes correctly to about 24 volts when detecting, whereas a good channel sits at about 2 volts and also goes to 24 in the presence of a spanner.
Loaded with 4K7 ohm to ground, so about 5 mA load, both good and bad go close to zero undetecting, but the bad channel stays at about zero in the spanner test.
So the hunt is on for a replacement. I could if necessary make up a bank of four individual proximity sensors but I'd rather avoid that if possible
Incidentally in previous posts I've referred to this sensor as made by Euchner - it's not it's a Balluff BES 516 B4 T0B-08-650 in case you have one in the odds box :lol:
Post by: awemawson on July 29, 2018, 02:53:31 PM
Post by: awemawson on July 30, 2018, 03:37:41 AM
I took the opportunity to blow out the chamber where it lives and take a photo of the 'pegged drum' or Hedgehog that encodes the tool position in binary. It also shows the clutch disk that is used to rotate the turret to the appropriate tool, currently in the disengaged state.
(The same AC Servo motor is used to both rotate the turret to the right tool, and drive the Powered Tooling )
. . . sorry about the blurry pictures but it's a bally difficult place to get a camera at - I did try with my WiFi endoscope but it was even worse !
Post by: awemawson on July 30, 2018, 11:08:12 AM
I found an hour after lunch to attack the internal fluorescent light in the lathe. It was absolutely filthy - the pictures don't do the grime justice. The upper surface was a good half inch thick with a concretion of brass swarf. I'd hoped to be able to take it down to clean it, but no such luck. Where the cable goes through the roof at the tailstock end is inaccessible on the other side without major dismantling. I got it off it's brackets which let me get to the rear. It should really have one of those circular military style plugs and sockets to allow removal to change the tube - maybe a mod for the future.
Hats off to Mr Muscle - I would usually use IPA to dissolve and soften caked on oily bits, but the tube in which the light tube lives, is almost certainly Poly-carbonate, which I know cracks like fury if wiped with IPA. The Mr Muscle did an amazing job so has gone on the list of workshop cleaners !
Remember - these 'filthy' pictures don't look half as bad as it was !
Post by: Pete. on July 30, 2018, 12:55:11 PM
Post by: awemawson on July 30, 2018, 02:10:56 PM
Well MORE developments - I've re-made contact with a friend I had years ago but lost touch with - from his garage he has unearthed (amongst many other goodies) a BRAND NEW four position Balluff proximity switch and also one of those field coil drive cards ! (which he designed !!!!! )
Post by: nrml on July 30, 2018, 04:38:03 PM
BTW why not a LED strip light like the Traub? Better lighting for the obligatory videos when the project is finished.
Post by: awemawson on July 30, 2018, 04:48:02 PM
This evening I decided it was time to get on with the turret tinwork - strip the old tatty paint to give me an idea how much more bashing it needs - it's by no means perfect but actually not as bad as I'd thought.
So first a coat of lethal paint stripper that penetrates your gloves, then a scrape down followed by another application of paint stripper and scraping, followed by a good scrub under cold water in the workshop sink using a stainless steel scouring pad. (Can't use hot water - it's unbearable when the paint stripper has penetrated your gloves and been absorbed into your skin - feels as though it's boiling!)
Hopefully just a light sanding / rotary wire brushing and the odd bit of filler in places, and they can have a light coat of paint blown over them tomorrow. I'm going to use the paint left over from doing the Denford Mirac, which is too white, but will do for a first coat to stop them rusting while I decide whether to have some slightly pinker stuff mixed up. It will need leaving for quite a time to harden before putting back.
Post by: awemawson on July 31, 2018, 06:07:18 AM
I have ordered up a litre of RAL9001, which is slightly more yellow and pink than the RAL9010 and a good match for the Beaver creamy colour according to my RAL chart.
Post by: awemawson on July 31, 2018, 08:31:08 AM
Post by: RotarySMP on July 31, 2018, 10:44:53 AM
Mark
Post by: awemawson on July 31, 2018, 11:11:26 AM
If you're doing a job you might as well do it properly. I was taught to take a pride in my work :med:
Post by: awemawson on August 01, 2018, 02:37:08 PM
Then despite the replacement proximity switches having arrived from Germany I earned some brownie points taking the wife to Rye for a coffee and look at a water sports place she wanted to investigate for grand child entertainment.
By the time we returned the paint had dried sufficiently for me to turn the bits over and spray the tops and outsides (Who said I'd calculated that :lol: ) and before supper I was able to re-assemble the replacement proximity switch into the four way block and test all four ways.
I'll give the tinwork one more coat on the outsides tomorrow as this paint is going on at only 1.5 thou per coat according to my film thickness meter.
This version of the switch has a nifty tell tale yellow LED inbuilt - if the other had they don't work any more ! One feature that I hadn't appreciated was that the mounting screw goes co-axially through a jacking screw, used to align the front faces of the individual elements to the housing.
Then it was a case re-fitting the four way block (I set the gap to 0.5 mm as the proximity sensors range is 0.0 to 1.1 mm) and of re-threading the cables up the ducting, re-making the connections and giving it a soak test changing tools and moving about. At the time of typing it's been running 20 minutes, so early days - fingers crossed.
Post by: JerryNotts on August 02, 2018, 04:19:42 AM
What film thickness meter are you using. I presume you are using wet paint, not powder coat.
Jerry
Post by: awemawson on August 02, 2018, 07:30:06 AM
Yes it's a wet paint system. I gave the items their final outside top coat this morning out in the sunshine as it was a relatively still day.
Last night I ran that soak test spinning the spindle, moving the axis's and tool turret revolving for over an hour and it ran faultlessly. However my Infra Red thermometer told me the the heatsink on the Field Coil Drive card Thyristor was at 125 deg Centigrade :bugeye: Now that's the maximum permitted JUNCTION temperature for the device which must have been far higher in fact.
So this morning I put my trusty AVO 8 in series with the field windings and they were drawing 4.5 amps - the card is only rated up to 3.5 amps apparently so I tweaked it down to a conservative 2 amps during testing, and it now is running at a slightly more civilised 60 degrees - still really too hot as, as it is mounted it is directly below an electrolytic capacitor which is being slowly cooked. Motor still seemed to work happily but of course I'm putting no load on the spindle.
Then it all went wrong :bang:
I'd been doing manual turret changes, foolishly stopped it part way through one, pressed the reset button, and it went into eStop with an error saying that the PLC program was not running. Somehow I'd corrupted the program.
So I then cleared down and reloaded the controller - it takes about an hour at 9600 baud, and all was right again. However when I went to initialise the Tool Turret it wasn't reading the 4 way proximity bit for Tool 8 where is happened to be. Squinting in at the gap it looked bigger than the 0.5 mm I'd set it to yesterday on Tool 1 - sliding in a feeler gauge brought up the reading, so I reckon that the drum with the projecting pegs is very slightly eccentric, Tool 8 being almost directly opposite Tool 1 where I'd set it to 0.5 mm. So I re-set the gap at Tool 8 to 0.25 mm and hope it doesn't scrape the face off the sensors when it turns round ! (it doesn't)
Now I need to re-write my diddy as it was wiped out in the re-load !
Got to worm, fly treat, ear tag and foot trim the sheep first though !
Post by: vtsteam on August 02, 2018, 10:17:16 AM
Now I need to re-write my diddy as it was wiped out in the re-load !
Wha? :scratch:
Must be English or some other foreign language.
Post by: awemawson on August 02, 2018, 10:28:11 AM
Written in Sinumerik's dialect of G Code, which in most cases is pretty standard. This one was only a dozen lines or so. But even so I should have saved it for future use by porting it out to a PC on my network . . . . but I didn't !
Post by: vtsteam on August 02, 2018, 10:41:30 AM
Post by: mc on August 02, 2018, 07:14:03 PM
I'm assuming it's the hirth coupling showing, but what I can't figure out is what's attached to what, and what moves.
It looks like the encoder wheel is attached to the nearest side of the hirth coupling, but assuming that's the tail end of the main turret/tool disc shaft, that means it's going the wrong way to lock...
Post by: awemawson on August 03, 2018, 02:49:33 AM
What differs from the patent application is that the encoder has been removed from the rear of the main shaft and put on the rear of the servo motor, and the addition of the four proximity switches that count the tool position in binary. In the first version the encoder could both count the disk and provide servo feedback as it was fixed effectively to the main shaft and hence tool disk. Once it was moved to the rear of the servo motor it could no longer keep track of tool positions, as at times it would be disconnected and not keep a fixed relationship.
Post by: mc on August 03, 2018, 06:43:29 PM
I've just had a read through of the patent, and hadn't realised the first diagram was for a basic turret without live tooling.
One final question, is the turret is also held locked by hydraulic pressure?
The patent mentions springs, but it would need a fair bit of force to keep things locked under load..
Post by: awemawson on August 04, 2018, 02:04:20 AM
I've come to the conclusion that there must be some setting up proceedure to get the front half of the rear Curvic Coupling synchronized - it carries the notch that the Index proximity switch detects. So that the rear Curvic mates smoothly when the front one disengages their angular relationship must be controlled, or when they come together either in the worst case it could be 'tip to tip' or if not so much out of place then a tendency to rotate a bit to engage.
Post by: JerryNotts on August 04, 2018, 03:33:28 AM
Jerry :beer:
Post by: awemawson on August 04, 2018, 03:50:36 AM
I think the patent description and drawings in this case are a fair representation of a slightly earlier, but VERY similar turret to mine, from which mine evolved. They have clarified quite a few details in my mind.
After a very short production run, as I understand it, they decided to buy in Baruffaldi turrets rather than make their own. This ties in with a history of Beaver's demise that I've read, where about this time they started outsourcing parts due to 'bean counter' pressure, as the Banks were calling in the overdraft.
Post by: awemawson on August 04, 2018, 11:59:51 AM
M24 S100 <LF> (M24 means start tool spindle, S gives it the speed to run at, <LF> is 'line feed')
Totally fails to spin the tool drive at 1000 rpm, and it creeps round VERY slowly
However:
M24 <LF>
S1000 <LF>
Works a treat :bang: No documentation on this, and these little things take AGES to find !
Now in retrospect the very slow rotation is because it still holds the speed command value from the last tool change, where the servo turns VERY slowly . . . but if you don't know . . . .
Then I went to more physical things for a bit of sanity. The door on the tail stock end that gives access to the tails stock handle has obviously had an 'issue' at some time, in that the tin work around it's opening was a bit bent, and the original door is missing. However someone has started to make a replacement, bent up from galvanised plate, with welded corners.
It's a bit of a rattly fit, the opening for the catch has been cut rather roughly, and it's been left somewhere damp, and not been painted. So the welds were heavily rusted. I attacked it with a rotary wire brush and sanding disk and it's slightly better now. The galvanising had gone all white and furry! I can't paint it until the piano hinge that I've ordered arrives - it'll need packing out side to side involving drilling holes, and that's best done before painting.
The catch - a Push and Turn from 'Southco, Lester, PA' must have suffered in the original accident, as it's body was badly squashed and a bit broken off one corner. They are still available, but it looks like this size (35 mm x 78 mm) has been discontinued. 21 x 45, 40 x 85, and 57 x 141 no problem - but not this one :bang:
A bit of judicious bending got most of the squash out, but this is thin Mazac so is just waiting to break - it'll have to do !
Post by: awemawson on August 04, 2018, 03:00:38 PM
Now at least the remaining blemishes are hidden by the rim of the catch
Post by: awemawson on August 04, 2018, 05:07:20 PM
This evening I've managed to draw a simple cone in FeatureCAM, post process it with my tweaked and adjusted post processor, upload it to the Sinumerik 820T controller using DNC4U, AND have the courage to run it full wack no restraints :ddb:
Now to be honest first time I'd nobbled the feed rates and spindle speed to very low values and had my hand on the eStop button (as you do !), but then once proved I let it rip, and both the machine and I survived
Being 'constant surface speed' turning and a steep sided cone the chuck didn't half spin at a rate of knots at the smaller end of the cone.
The post processor code still needs breathing on and tidying up, but it's definitely on course.
I still need to master work offsets and tool offsets before I can actually make chips, but before I do that I need to invest in some 25 mm shank index-able tooling as most of my existing stuff is 20 mm.
Now having a 'rear' tool turret and some VDI40 holders that jack the shank to the top of the slot and others that press it down, I need to standardise and make a few decisions. It affects the handedness of the tools and the direction that you spin the chuck , CW or CCW. I need to find a quiet hour to get my head around the variables without the usual interruptions of life.
Post by: PK on August 04, 2018, 08:49:24 PM
AND have the courage to run it full wack no restraints :ddb:We have a saying at work; There's no avoiding the "Push the red button and trust in Jesus" moment.
Post by: Pete. on August 05, 2018, 10:49:22 AM
Well I'm CHUFFED - though I say it myself :clap:
This evening I've managed to draw a simple cone in FeatureCAM, post process it with my tweaked and adjusted post processor, upload it to the Sinumerik 820T controller using DNC4U, AND have the courage to run it full wack no restraints :ddb:
Now to be honest first time I'd nobbled the feed rates and spindle speed to very low values and had my hand on the eStop button (as you do !), but then once proved I let it rip, and both the machine and I survived
Being 'constant surface speed' turning and a steep sided cone the chuck didn't half spin at a rate of knots at the smaller end of the cone.
The post processor code still needs breathing on and tidying up, but it's definitely on course.
I still need to master work offsets and tool offsets before I can actually make chips, but before I do that I need to invest in some 25 mm shank index-able tooling as most of my existing stuff is 20 mm.
Now having a 'rear' tool turret and some VDI40 holders that jack the shank to the top of the slot and others that press it down, I need to standardise and make a few decisions. It affects the handedness of the tools and the direction that you spin the chuck , CW or CCW. I need to find a quiet hour to get my head around the variables without the usual interruptions of life.
Now that's taking the bull by the horns!
So, is the turret fully operational now then Andrew?
Post by: awemawson on August 05, 2018, 04:39:17 PM
I don't fully trust it due to previous problems but at the moment it's doing what it's supposed to.
Just by co-incidence (not really !) I have a former ex Beaver service engineer check into one of our holiday cottages this evening with his wife and dog. I really don't want to make this a bus mans holiday for him but no doubt I will be making a full down load of his brain over the next few days ! (any one got any truth drugs !)
This is a nice chap I met first when I bought my Beaver Partsmaster, and the carriers mangled the ball screw by not using the shipping clamps. I'd lost touch with him, but by co-incidence he needed accommodation for a job he was doing locally this week.
Post by: WeldingRod on August 05, 2018, 11:28:01 PM
I'm might be asking too ;-)
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Post by: Pete W. on August 06, 2018, 05:11:23 AM
I've been following this project and finding it interesting.
I hope that his dog and yours will get along OK. Shall you have to teach his dog how to behave in proximity to sheep?
I had a 'switch it on and it works' moment here yesterday. Very QRP by comparison with your project - a mere 350 milliamps at 12 Volts! I won't go into detail here but will try to recount some of my activity in a new thread. Still, there was that grateful and relieved release of breath that I'm sure you've experienced too!!!
Post by: awemawson on August 06, 2018, 05:52:27 AM
Ok, I've gotta ask... my sole reference for chuffed-ness come from the British Baking show. My kids are asking; what is chuffed, and why should someone else need to say.it about you?
I'm might be asking too ;-)
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"pleased, happy," c.1860, British dialect, from obsolete chuff "swollen with fat" (1520s). A second British dialectal chuff has an opposite meaning, "displeased, gruff" (1832), from chuff "rude fellow," or, as Johnson has it, "a coarse, fat-headed, blunt clown" (mid-15c.), of unknown origin.
Post by: awemawson on August 06, 2018, 06:06:03 AM
Yes switch on moments and trying new operations are definitely stomach clenching moments. Trouble is that this machine has so much power behind all it's movements that it won't take prisoners if you make an error, and metal will be bent!
This morning I've being getting my head round work offsets (G54 etc) as implemented on this machine, and trying to get things set up so things I create in FeatureCAM are all located within the 'safe zone' where spinning chucks and tool turrets DON'T get into intimate contact with each other!
Believe me a 10" chuck spinning at 3500 rpm with 26 kW behind it has an awful lot of stored energy just waiting to leap out and catch you unawares, it also kicks up quite a wind with the jaws acting as fan blades.
The hinge for the Tail Stock access door arrived this morning, but it is really too flimsy for this application. I've ordered a far heavier duty one (2 mm thick) from RS Components that should arrive tomorrow morning. This one has the advantage also that it is un-drilled, so I can pick up and reuse the existing tapped holes in the door frame.
Post by: DICKEYBIRD on August 06, 2018, 11:24:16 AM
This morning I've being getting my head round work offsets (G54 etc) as implemented on this machine...When you get work offsets working well, could you please take a few extra minutes to describe what you did & how you did it? I read every word in all your threads to trying to learn how to do things right but work offsets coincidentally are especially important to me right now. I've always muddled my way along in Mach3 Turn & never learned how to use work offsets. I just programmed everything in an (what I called) absolute manner. It worked & many parts were made successfully but tool changes were difficult. After finally getting a decent controller & software now, I'm starting over & trying to learn how to do things correctly.
Post by: awemawson on August 06, 2018, 12:15:29 PM
When my lathe seeks it's reference points, it finds them at X= 530, Z=660 (millimetres of course) so it then sets up it's co-ordinate system with those positions having those values.
Now on this lathe it uses it's zero reference as the face of the chuck - (the Traub used the chuck mounting face ie the back of the chuck). So if you use a CAD program to produce your G code, which will conventionally use the outermost end of the stock (away from the chuck) as it's Zero Point for Z, then you need some method of 'shifting the zero' . (For a lathe it is really only the Z axis you are worried about until you come to tool length compensation but let's ignore that at the moment)
So this is where G54 'work offset' comes in. There is a screen on the 820T controller under 'settings' that lets me pre-set an X and Z value for the G54 offset command (also for G55,G56 & G57) - I have loaded mine with a Z value of 300 at the moment to keep things well away from the chuck as I am testing.
OK back to the plot - when the controller gets a Z address to move to, it adds it to the Z value stored in the currently active work offset command (Also the tool length compensation value) so if I tell the machine to "G00 Z10.00" it actually moves to Z300 +10 = Z310
By issuing a G53 you can cancel any offsets that are in effect.
Now today I've been using both those commands to ensure that the FeatureCAM post processor that I am tweaking always moves the tool turret to a safe place before a tool change. It has a place that you can pre-set it before running the PP, but then the value it assigns will be massaged by the G54 that is in effect and move to the wrong place.
My solution is to have a little macro always available in the controller thus :
%SPF 54 (Sub Program L54)
G0 G53 G71 G90 G40 D0 X450 Z400 (full speed move to X450,Z400, cancel G54, Metric measurements, Absolute move,cancel cutter radius compensation, no tool offset)
G54 (Reactivate G54 work offset)
M17 (Sub-Program end
Which is called by the main program that the PP generates thus:
%MPF 8
( CUST PART# )
( 8-6-2018 )
N25 G71 G90
N30 L54 P1 (Call Sub Program L54)
N35 T3 D3 ( TOOL 3 EN_TURN_55 )
N40 @714
N45 G92 S3500
N50 G96 S170 M4
N55 M8 (MSG, ROUGH TURN TURN1 )
N60 L54 P1 (Go to safe place)
etc
etc
Post by: DICKEYBIRD on August 06, 2018, 02:22:31 PM
Post by: awemawson on August 08, 2018, 11:23:34 AM
I've managed to find the logical word in the controller that represents the Touch Probes making contact, and for the simpler HPA arm mounted one proved that it works.
For the more complex Optical Probe I have a feeling that it isn't working - the actual contact switch on the probe is working, the Infra Red wake up signal is being issued by the cabinet mounted transmitter / receiver, but the electronics on the probe head isn't waking up and replying. I made a simple IR receiver up using a QSE158/9 IR ic that contains the detector and an amplifier / driver that turns on a visible red LED when IR is found, and proved that the 'OMM' unit that is cabinet based is transmitting OK but being ignored. So far I've not managed to open the unit up for further investigation.
Then the Postman brought a mystery package - contents unknown :scratch: Turns out that a very kind MadModder is my benefactor, and sent me a compatible replacement catch for the one that was damaged. Same hole in the door but slightly more streamlined outer profile. Thank you very much Smiffy. However no further door progress as my 'next day delivery' from RS Components still hasn't arrived two days later.
I've been doing quite a bit of research how this machine is supposed to position it's main spindle rotation-ally for milling using the power tooling. There is an M code 'M19 S<angle>' that should stop the spindle at the specified degrees, but although it stops the spindle, the place is random :scratch: I've managed to find the bit of the controller that monitors the angular spindle position, and sure enough it displays correctly if you manually turn the chuck, or set it slowly turning - but the stopping when there bit doesn't seem to be functioning properly.
The another delivery of Tooling arrived from APT. I thought that I'd ordered a left and a right handed version of tooling for TNMG1604 (triangular) inserts, for SNMG1204 (square) inserts, and for DCMT11T3 (diamond) inserts, but it seems that I cocked the order up and the right handed TNMG one was infact for a 20 mm square shank :bang: Never mind it'll go on the Colchester Master and I've re-ordered the correct item
Oh and another positive - I've braved the 'Gear Change Mechanism' and despite previous reports that it might have a fault, it seems to work OK :thumbup:
Post by: awemawson on August 08, 2018, 01:55:14 PM
The actual tail stock barrel is advanced hydraulically by an M11 command, and retracted with an M12. Despite me issuing an M51 command, the controller got all upset reporting that the tail stock was unclamped, and faulted out if I issued an M11. Fairly obviously something to do with the pressure switch, and eventually traced to intermittent contacts. Almost certainly due to the machine sitting unused for many years
Now it's a sealed unit, so no physical cleaning or squirting contact cleaner was possible. Remembering back to my days with relay logic, most are arranged that the contacts rub a little as they open and close to remove any oxide that forms, and the 'wetting' voltage and current are important to keep the contacts low resistance.
OK maybe I can increase the wetting current - I daren't increase the voltage much as I don't know the contacts ratings. A quick test with the AVO showed me the controller input circuit was passing a mere 15 mA when the contacts decided to close.
Now I had already written a little diddy program that clamped and unclamped the tail stock every second in an attempt to clean the pressure switch contacts, things had improved but about one in 35 closures was unsuccessful.
Time to roll out the big guns - I wired the contacts to my trusty current limited lab power supply, set the volts to 30 and the current limiting to 250 mA and ran the program. Initially still problems but after about 20 seconds - hey we have reliable contacts - this rather off the wall method actually works :ddb:
Lab supply put to bed, contacts returned to the controller to play with, and let the little program run again, which it did faultlessly :clap:
Post by: Will_D on August 08, 2018, 04:22:40 PM
Guys: When Holywood casts the movie who should play Andrew.
PS: How are the pigs?
Watering and cutting Rugby pitchers is keeping me out of the workshop and is so boring
Joke:
Was talking to a native American friend yesterday.
What is your wifes name is asked.
4 Horses is her name.
What a lovely name for the wife, What does it mean?
Nag, Nag, Nag, Nag!!
Post by: awemawson on August 09, 2018, 11:50:56 AM
At last today the heavy duty piano hinge arrived for the Tail stock Door, so a suitable length was cut off, I picked up the four tapped M6 holes in he door frame and drilled matching 6 mm ones in one leaf of the hinge. When I'd checked that they aligned OK, I opened the hinge holes to 8.5 mm to get latitude for adjustment when the door is swung.
After a test fitting of hinge and door balanced together in the frame, I then spot welded the un-drilled leaf of the hinge to the door, gave it all a good clean up with IPA, and sprayed the inside RAL9001 to match the machine.
The weather is distinctly cooler and it's raining today, so although the paint was 'touch dry' after an hour I left it a couple of hours more before inverting it to spray the outside.
The Postman brought the replacement lathe tool that I had wrongly ordered as a 20 mm shank rather than the 25 mm that I'd intended - so when I'm brave I can start tooling up.
Today I've spent quite a bit of time investigating how to position the main spindle to a known angle. There seem to be two 'M' codes involved. 'M20' that enables the spindle drive, and 'M19 S<angle>' that orients the spindle to the required angle. I have example programs showing me how it works but it doesn't :bang:
I even called up the chap who used to use this lathe to confirm that the lathe has the capability, which he confirmed, there must be some parameter or setting needed to enable it I reckon :scratch:
Post by: modeng200023 on August 09, 2018, 03:04:05 PM
Post by: awemawson on August 13, 2018, 04:41:34 PM
Today I've identified EVERY connection to the KTK Mentor spindle drive, and proved to my satisfaction that it is working properly when commanded. I have also been through every input line and output line that has anything remotely to do with the spindle or it's positioning, and proved it works. At a logical level it's pretty simple. The Mentor drive takes in an analogue value that represents speed (-10,0,+10) and has an input from a tacho generator that represents actual speed. There are various enable and inhibit signals all of which work. If I drive the spindle at 1000 rpm clockwise I get an analogue input of +3 volts and a tacho gen output of -60 (rounded figures). If I drive the spindle anti-clockwise at 1000rpm I get an analogue value of -3 volts and a tacho gen output of + 60 volts. If I manually turn the spindle I can display the output of the shaft encoder in degrees and they are sensible.
Conclusion: the Mentor drive system is working, as is the encoder feedback of position to the controller. The problem MUST lie in the controller itself or it's parameters.
I've then been through every parameter that I can find that has anything remotely to do with M19 spindle positioning, and again everything looks sensible. I've re-loaded the controller three times from the back ups that I sourced - even set the baud rate for loading down a couple of notches in case something was being miss-read.
. . . argh !
So to restore my sanity I've swung the Tail stock Door now it's paint is a bit harder. Paint is a bit lighter than the original, but will have to do.
Earth shifting tomorrow if the weather is kind, so maybe my spinning head will clear !
Post by: russ57 on August 14, 2018, 12:40:21 AM
Sometimes the act of explaining it helps you to realise the issue.
Or, less likely, one of us may see the flaw.
Russ
Post by: awemawson on August 14, 2018, 02:05:30 AM
Post by: hermetic on August 14, 2018, 06:23:09 AM
Phil
Post by: cnc-it on August 14, 2018, 08:13:39 AM
Post by: cnc-it on August 14, 2018, 08:28:23 AM
Post by: awemawson on August 14, 2018, 12:09:51 PM
Post by: awemawson on August 14, 2018, 12:15:09 PM
On the spindle orientation..a very odd fault..as you would think the control would alarm if it wasn't in the correct position?
It just 'hangs' with the running light lit, so I expect that it's waiting for an input from some point on the ladder logic. I just wish I could source a copy of 'Step5' software that talks to the controller and lets you examine the PLC ladder in real time. All the hooky copies I've seen so far are missing the authorisation code :palm:
Post by: awemawson on August 14, 2018, 04:27:51 PM
240 volt 80 mm axial ball bearing fan ordered from RSComponents along with some M4 nylon stand off pillars arrived this morning while I was pushing earth about with the JCB803. This evening I drew up a simple mounting plate in AutoCAD which via SheetCAM was ported to the CNC Plasma table and cut out of 2 mm steel plate, edges bent up to form a flange for rigidity, and a test assembly performed.
All looks good, so it got a coat of Satin Black from a rattle can, and I'll probably fit it tomorrow if time permits.
I praise the day I rescued that CNC Plasma Table - oh boy does it make this sort of thing easy :clap:
Post by: cnc-it on August 14, 2018, 05:29:52 PM
On the spindle orientation..a very odd fault..as you would think the control would alarm if it wasn't in the correct position?
It just 'hangs' with the running light lit, so I expect that it's waiting for an input from some point on the ladder logic. I just wish I could source a copy of 'Step5' software that talks to the controller and lets you examine the PLC ladder in real time. All the hooky copies I've seen so far are missing the authorisation code :palm:
I have had this happen on a few different machines...it always turned out to be the post processor..either me using the wrong one for the machine or when I was testing a new modified post. If it's a PLC error or a mechanical error I always get alarms..but I have never used Siemens..only Hurco, Fanuc and Heidenhain.
John
Post by: awemawson on August 14, 2018, 05:45:08 PM
On the Generation 2 TC20 Lathes there is a 'Setting bit' that turns this feature on. I have the details for it. I can identify no such bit on this Generation 1 machine, but I'm sure that there must be some mechanism to enable or disable it, as the necessary spindle encoder was a optional extra.
I'm sure the key is going to be getting hold of a working copy of the Step5 software, though no doubt using and interpreting it will be a long and involved process !
Post by: cnc-it on August 14, 2018, 07:11:18 PM
Post by: awemawson on August 15, 2018, 08:07:00 AM
First I completed the assembly, incorporating a fused terminal block, then I re-set the field current back up to 3 amps. This involves intercepting the FXM-3's output and inserting an Avo. Pot duly tweaked. Then I replaced the original card mounting screws with the nylon pillars and wired it up.
All very straightforward. I can't now point my I/R thermometer at the Thyristor heat sink, but from the flow of air over it I'm sure that it's fine :scratch:
Last night in a flash of inspiration, I remembered that in the machine door pocket had been a floppy disk with three files on it - copies of the machine parameters and PLC program. Just suppose the PLC program was different . . . . could that have the key to the axial positioning issue? So I ploughed through page after page of data and sure enough I found a difference in one line . . . . . whoopee !
So having fitted the fan, once more I re-loaded the controller data just hoping . . . . no, no such luck . . .no difference . . .and no idea what the different data represents. Another oddity to tuck away and remember in the future.
Post by: cnc-it on August 15, 2018, 09:42:40 AM
Post by: awemawson on August 15, 2018, 11:05:43 AM
Yes I agree..with a name like Step 5 it sounds like only the tech who wrote the software knows how it works :smart: but well worth a try!
STEP5 is actually a PLC programming language developed by Siemens but has been superseded by STEP7. I did persuade Siemens to let me download a trial version of STEP7 (1.8 GigaBytes!) which took 7.5 hours to unpack then produced nothing useful :bang: Anyway apparently STEP7 won't talk to this generation of controller !
(STEP5 runs under DOS or the earlier versions of Windows before NT)
I do actually have STEP5 but no authorisation code for it, and Siemens can't supply as it's obsolete !
Post by: David Jupp on August 15, 2018, 12:05:59 PM
Post by: awemawson on August 15, 2018, 12:13:47 PM
I suppose I'm going to have to apply the 'infinite number of monkeys' approach, and just keep slogging on. Now I'm beginning to realise how they felt at Bletchley Park solving their enigma !
Post by: cnc-it on August 15, 2018, 12:28:47 PM
Post by: awemawson on August 15, 2018, 01:04:59 PM
The redesigned board is simplified, has only one transformer, and uses a relay to indicate 'OK' rather than semiconductors. I've had the comment from someone else who repaired Beavers that the new cards were more reliable than the original.
Post by: cnc-it on August 15, 2018, 01:42:40 PM
Post by: awemawson on August 15, 2018, 02:00:38 PM
Post by: cnc-it on August 15, 2018, 03:29:31 PM
Post by: awemawson on August 16, 2018, 01:14:14 PM
Imagine my surprise when one popped up for £12.95 'buy it now' (OK plus £16 postage) on German ebay carrying a 3 month warranty. It took microseconds for my finger to press the button. Now you tend to get what you pay for, but the seller has good feedback, has already given me feedback, and confirmed the order.
Now frankly it's very unlikely to be the fault, but well worth having 'on the shelf' :ddb:
(anyway it's not corroded like mine - see the pictures, first mine then the one I've bought)
Post by: awemawson on August 18, 2018, 05:53:08 AM
:mmr: :mmr:
Post by: Pete W. on August 20, 2018, 06:09:32 AM
I had a sudden qualm - are they the correct 'hand'? But I checked your photos on the previous page of this thread and I see that the new tools you bought are both RH and LH, phew!!
Post by: awemawson on August 20, 2018, 09:03:52 AM
Not a huge amount of progress recently as I've been tied up with a few other things - example just been making up the latest pork order of 116 kgs of freezer ready pork for customers this afternoon. (Sorry Will-D - that was those two Berkshires!) Also both my workshop PC and Printer decided to die one after the other. PC resurrected but much hassle getting it's Win7 re-authorised having replaced the motherboard, printer sadly terminal and replacement ordered!
However I HAVE actually cut metal with the lathe - not a lot, but just enough to 'set' a couple of tools the old fashioned 'cut and measure' way. The Renishaw HPA Tool Arm is fully working, but so far the only software I've located is a sub-routine that admittedly does most of the work, but the program that calls it is missing.
The Siemens controller is rather convoluted in the way it works. At the high level you have normal G code programs which can call subroutines and / or 'cycles'. Then the Subroutines (which are held in a different bit of memory) can use 'R Parameters' (again in a different bit of memory) as can the 'Cycles' - the cycles (identified with the '@' sign can be very simple functions such as 'jump to location' up to quite complex one such as 'move towards the probe, stop when you hit it, and transfer the X&Z co-ordinates to R parameters'
And just to complicate matters further there are three 'channels' that programs can run in simultaneously - not explored that feature yet :scratch:
In the case of the Tool Probe Tool Offset program, a set of R parameters hold the location of the probe, and it trots off and chooses the tools one by one, reads their roughly set (by ruler +/- 5 mm) position, finds which way the cutting edge faces from a manually set table, and advances the tool into the probe, hopefully then stopping and transferring the accurate co-ordinates into the Tool Table.
At the moment my puzzle is how to accurately measure the static position of the Renishaw HPA Tool Probe. The slightest contact and it's tip of course moves so darn difficult, especially as you are in free space with no reference planes to work from. I suspect that I'm going to have to make up a 'setting tool' with accurately measured offsets done on a surface plate, measure it with the HPA Tool Probe and make corrections to it's stored location until the setting tool measures correctly.
. . . but other things in life get in the way !
Post by: awemawson on August 20, 2018, 09:24:12 AM
A few clues to set you off - these are the meanings of some of the 'cycles' :
@100 = absolute jump
@122 = If / THEN / ELSE jump
@320 = Transfer Tool Offsets to R parameters
@720 = Flying Measurement
. . . simples really :ddb:
Post by: awemawson on August 22, 2018, 12:39:04 PM
A complete Input Output framework with four i/o cards for the princely sum of £13.43 plus £16.12 postage, and the awaited Measuring Circuit (Basically the card that handles the Encoders, and produces the analogue outputs to the DC servo drive) again for a bargain basement price of £12.98 plus £14.50 postage.
At those prices I really wasn't expecting much, but they came immaculately packed, wrapped in anti-static, AND THEY WORK :clap: No idea why they were so cheap - eBay is full of ones at more than ten times the price.
There are two versions of the Measuring card, a wider one like my original that will take a daughter board, and this version, which apart from the sockets for the extra card and the width of the frame are identical. (I knew that this was the narrow version.)
I plugged it in and tested it and all functions perform just like my original, so it's a good cheap shelf spare, as is the I/O rack. Needless to say the M19 axial positioning issue wasn't affected, but then I didn't expect it to be - I'm more and more certain it's a software 'setting bits' issue
Post by: awemawson on August 22, 2018, 12:47:25 PM
Ploughing through and translating that subroutine / sub-program that I attached above I found several errors where it could not possibly have been able to run - they looked like typos, with variable names being muddled up. Anyway I concentrated on 'Type 3' tools and got the section of code measuring them working. Gosh it must be about the most stressful bit of coding, launching a massive tool turret at a delicate probe and hoping it remembers that it's supposed to stop when it kisses.
I liken testing the program after you've written it to letting your child cross the road for the first time :bugeye:
Anyway Type 3 tools now can be measured, and I need to work on the other types when time permits. The Type 8 tool as per the illustration a/ isn't dealt with in the program, and b/ I haven't a clue how I'm going to do it - X measurement is no problem, but how the heck do you do Z :scratch:
There is a video of it measuring, uploading to Youtube as I type - I'll include it when its cooked!
Post by: awemawson on August 22, 2018, 01:14:36 PM
Post by: tom osselton on August 22, 2018, 02:15:01 PM
Post by: awemawson on August 23, 2018, 07:02:24 AM
To gain a bit more confidence with it I set up a parting tool, roughly measured the tool offsets with a ruler, then used the automatic system to measure accurately. Of course it is only as accurate as the accuracy of the tool probe location has been measured, and I've not grasped that particular nettle yet !
Interesting to see the correction that the program has made to the tool table - first picture is my initial manual measurement, and the second one the result of running the program.
The manual measuring step is necessary to get the the tool 'in the zone' before launching it at the probe.
Post by: awemawson on August 23, 2018, 11:25:03 AM
With this operation, the tool has to go past the Tool Probe, and come back away from the chuck to measure the correct side for Z
. . . anyway it worked with remarkably little tweaking :thumbup:
Post by: awemawson on August 26, 2018, 05:26:16 AM
By way of a test of this process I drew up a simple dome ended bar, ran it through the Post Processor, uploaded it to the 820T controller and made it. All went very well until the last 'finishing pass' when the index-able insert chipped. This is quite consistent - I know, I've chipped four tip edges so far :bang:
Assuming I was doing something wrong a lot of head scratching ensued :scratch: :scratch: But then the penny dropped - the program is driving the tool well past centre on the finish pass - in fact 6.6 mm past centre - then engaging with the work resulting in an upwards force on the tool until it is back the correct side of the centre line. It is probably made worse by the fact that the tool has only a very small clearance angle on the chuck facing side. However I tried it with the TNMG1604 illustrated below and also with a DCMT11T3 with identical results.
Still, I'm pleased that the lathe is at least now producing swarf for the first time in a decade :thumbup:
It was then I looked at the FeatureCAM simulation screen, and saw the finish pass going well beyond centre - not sure how I can tweak that - I need to do some digging in the bowels of FeatureCAM and see if there are limits or whatever that I can set.
Amazingly the finish was not at all bad on the dome end considering the wrecked tip, but of course it can't be to size with a bit of carbide missing !
Post by: Will_D on August 26, 2018, 05:59:17 AM
Post by: awemawson on August 26, 2018, 06:03:48 AM
Post by: cnc-it on August 26, 2018, 04:38:45 PM
Under the finish tab in Feature Cam it has finish point and start point..I presume you have tried that with no effect?
Post by: awemawson on August 26, 2018, 05:18:43 PM
I'm running FeatureCAM 2007 V 13.1.0.28
Post by: cnc-it on August 26, 2018, 05:42:12 PM
Post by: cnc-it on August 26, 2018, 05:48:52 PM
Post by: awemawson on August 26, 2018, 06:02:46 PM
Not sure those settings are still in 2007 version but hopefully they are . I'll experiment in the morn. Meanwhile I've been fighting power cuts. :bang:
Post by: cnc-it on August 26, 2018, 06:13:59 PM
Post by: awemawson on August 27, 2018, 03:14:46 AM
Specifying a start point on the Z axis slightly away from the Z=0 point with X=0, sure enough it moves there having done the rough pass, but then continues to the X=-6.6 point that it previously was doing and carries on.Only done it in simulation, as I'm running out of good edges on my inserts !
Post by: awemawson on August 27, 2018, 03:56:28 AM
Another setting in the MISC tab is approach angle, which was set to zero. Altering it to 30 degrees gives a much more healthy state as far as the insert is concerned - no more upwards pressure tending to chip it.
So I shifted the G54 offset to -1 mm from where it was (thus skimming a further 1 mm off the part) and ran the new version with the 30 degree approach - guess what - no insert chipping :ddb:
My thanks to John for starting me looking at this area of Featurecam :thumbup:
Post by: PekkaNF on August 27, 2018, 05:25:25 AM
I still don't quite grasp why does cutting edge starts wrong side of the spindle axis (rotating wrong direction in cutting direction, inserts don't stand that or rubbing). Is there a offset relative to spindle axis and why it is default? Or is the insert tip radius decade off? I don't get that.
Pekka
Post by: awemawson on August 27, 2018, 07:08:36 AM
I can see why the finishing cut approaches slightly beyond centre to eliminate any possibility of a pip, but not 6.6 mm ! The program is set up to move the tool tip allowing for tip radius, so I don't see ANY reason why there should be material other than the 'finish allowance' left to machine.
OK the 30 degrees approach has solved this particular issue, but I'd like to understand the generality
Post by: cnc-it on August 27, 2018, 09:39:03 AM
Post by: awemawson on August 27, 2018, 03:59:47 PM
Post by: awemawson on August 30, 2018, 02:59:59 PM
Today I was experimenting with threading programs - I've not actually got a threading tool mounted yet but wanted to prove that the inbuilt threading cycles work. (they do :thumbup:) They use the same position encoder that is involved with the axial spindle stop function (M19) that I still haven't got working (*) and to get a good finish whirl away at maximum spindle speeds using loads of power.
Well I managed to trip the 32 amp type C breaker that the 3 phase is sourced from, and the SY flexible cable to the machine was distinctly HOT ! - not unexpected, the 27 kW spindle motor is the main load and at full tilt accounts for 48 amps at 415 volts three phase. The SY cable being 2.5 mm csa is only rated at 24 amps !
So I'm going up to 6 mm csa SWA cable rated at 53 amps, and will upgrade to a 63 amp 5 pin interlocked socket and plug (Looking for one of each if you have them skulling about !)
(*) I've made contact with a company who have two of these lathes of a similar vintage, and although they don't actually use the axial positioning M19 facility know that it is embodied, and are happy for me to go and poke around and see if I can find out what enables it.
BTW these two lathes are used intermittently making parts for Merlin engine rebuilds so a visit should be extremely interesting anyway.
Post by: cnc-it on September 01, 2018, 07:58:59 AM
Post by: awemawson on September 01, 2018, 10:47:38 AM
The taper roller bearing was seized solid and the rollers rusted , so I assume the the seal at that end had failed. However the (rather expensive looking) slim taper roller bearings were in good order.
I'd had a bit of a mare getting the old taper roller bearing out - drifting from the outside was the only way but the angles were too steep. I thought about making a puller and slide hammer, but looking on eBay I could see that it just wasn't worth the effort. A nicely cased set of bearing inner extractors and slide hammer were mine for £18.90 including post. OK Chinese but probably no worse than I'd have made myself, and they will come in handy in the future. The extractor worked faultlessly, needle bearing outer removed so I could measure up, and an online order placed which is what arrived this morning.
1st September today so first I had to cut the field hedges with the Twose Fail (not allowed to do it before 1st Sept, and this time of year things very quickly get too wet to put the machine on the ground. A few hours later - (I hate driving the flail tractor, it bounces all over the place!) and I'm able to get back in the workshop and re-assemble the Powered tooling.
Simple enough - gently tap the well oiled seals and bearing back into place, lubricate it with high melting point lithium grease, pop the shaft and collet chuck back in and tighten a few screws -" job's a good 'un "
I've decided not to modify the drive dogs on the powered tooling to suit the lathe, but rather to modify the lathe to suit the powered tooling. My logic being, these Baruffaldi tools are quite rare but do surface at times, whereas the genuine Beaver ones I've never seen and probably never will. So when the time comes I will remove the lathe tool drive shaft and dog and make a replacement longer one to fit these tools.
Post by: awemawson on September 01, 2018, 10:49:31 AM
Post by: awemawson on September 02, 2018, 06:04:38 AM
Taking this one apart revealed that the needle roller bearing was actually in very good condition, but the pair of opposed taper roller bearings were locked up solidly. They slide onto the shaft and are retained and adjusted by the usual nut arrangement that would usually have a tab washer or some other device to stop it unscrewing.
This one looked to have been attacked with a cold chisel mangling the nut into the shaft thread. Problem was, the shaft has a 36 mm hex flat behind the collet nut thread, and the closer nut thread is greater than 36 mm, so any spanner would need to be thinner than 9.5 mm to fit. All my 36 mm spanners are big fat things, so the job took a slight detour into making a spanner.
I decided rather than make a conventional spanner shape, I'd make a plate that I could firmly grip in the vice, as it would also support the shaft as I worked on it.
Usual thing, draw it in Autocad, push it though SheetCAM, cut it on the plasma table using MACH3 - and again as usual the Plasma Table did an excellent job. A minimal bit of clean up with a file and we were good to go.
So, into the vice and now I can use the hook spanner to good effect unscrewing the nut - by this time the bearings had freed up and were turning smoothly. I'm running out of time (Need to be presentable for a BBQ with friends for lunch) so I will leave removing the YL-TIMKEN-X-32006X bearings for inspection later. But I did find that they are available on the web at £14 each)
. . .to be continued . .
Post by: seadog on September 02, 2018, 09:15:00 AM
Post by: awemawson on September 02, 2018, 11:54:02 AM
Post by: seadog on September 02, 2018, 12:04:00 PM
Post by: awemawson on September 02, 2018, 12:30:25 PM
Now back from the BBQ (where the host / hostess were embarrassingly serving my pork and sausages!) and have managed to knock the bearings off the shaft - they look at a first inspection to be fine but I can't get too involved as I'm still in my glad rags !
I'll give them a good wash out in the morning with spirit and see i they still seem OK, in which case it's just a 'put it back together' job :thumbup:
Post by: seadog on September 02, 2018, 12:34:13 PM
I'll give them a good wash out in the morning with spirit and see i they still seem OK."
You should have put your overalls on then... :)
Post by: awemawson on September 02, 2018, 04:54:10 PM
As expected the bearings on examination proved perfectly serviceable, so with a bit of lithium grease and application of the broaching press it was re-assembled. I used the existing M28x1 locking nut: examining the male thread on the shaft the 'damage' was actually an intentional scallop taken out to receive the deformed nut as a locking device. Adjusting for 'reasonable' drag and pre-load brought the nut up remarkably close to where it had been, and I secured it with three pops with my large centre punch (inherited from my Grandfather who was a mill wright)
Stealing an ER32 cap nut from some spare tooling for my Beaver Partsmaster made the job complete. Just the 90 degree one to tackle some time in the future.
Post by: awemawson on September 04, 2018, 10:03:03 AM
When I came to power the machine up 'just one more time' there was a big bang and a puff of smoke from the cable clamp on the 32 amp plug. Investigation showed that the insulation of the cores had softened, bringing the wires into intimate electron passing closeness :bang:
Now using this feed was always an interim solution, only intended for initial testing - I'd intended to upgrade. Obviously now was the time ! The 32 amp type B MCB was wired to the 32 amp Commando socket in 4 mm 'singles' cables in ducting, rated at 32 amps.
So I hatched a plan - running 6 mm Steel Wire Armoured (SWA) cable (rated 53 amps) round the workshop ending up on a 63 amp Commando Plug & Socket thence running in 6 mm SY flexible cable (rated 42 amps) to the machine. But also to upgrade the breaker to a 50 amp 'Type D' motor rated one.
I put out a plea for cable and plugs and sockets, but to my embarrassment found I already had cable rescued during the site clearance for the Tractor Shed, and a box of 63 amp commando plugs and socket that I've no idea where they came from :bang: (plonker as I'd already ordered some on ebay)
So getting it all together needed a few things. The big Commando Plugs use 'PG29' threads or Panzergewinde threads (*) and my SWA terminations are M20 x 1.5 mm standard conduit so an adaptor bush was needed. No local electrical factors carried them, so I made one on the manual lathe. The cable , socket and plug are beefy things needing a hefty mounting plate, so I cut one on the Plasma Table.
Then threading massively stiff SWA cable round the over crowded workshop and fixing it required much emptying of shelves etc and quite a bit of ingenuity - that stuff is alive and just waiting to pounce and knock expensive tooling over when you're at the other end of the coil up a ladder and unable to stop it :bang:
Anyway, cable up, entry made into the Distribution box, and made off across steelwork trusses to where a pair of empty holes were just asking for a mounting plate to be bolted on for the 63A socket.
Meanwhile I fixed a 'riser' from the machine up to socket level (made from pedestrian barrier bits - thanks Pete) and found a way through various internal ducts and cabinets to minimise the external cable run, fixing to the ceiling of the main electrical box using sticky Ty-Wrap pads reinforced with a nut and bolt to prevent pull-off. (again thanks Pete for the pads). I also fixed a short bit of Din rail to take terminations for the Earth and Neutral cables as this machine had none (I ALWAYS run a neutral when wiring, even to wall switches - you never know when you'll need it!)
(* https://en.wikipedia.org/wiki/Panzergewinde )
Post by: awemawson on September 04, 2018, 10:20:39 AM
So a plate got cut out from 9 mm steel, painted and bolted up with the 63A socket on it. The SY cable was pulled through the internal ducts and threaded up the 'riser' protected by an anti chaffing shield, then fixed to the main electrical box roof, made off to the Main Machine Isolator and plugged in.
. . . the moment of truth . . no putting it off . . . time to throw the switch Igor :bugeye:
Now I had been concerned if any damage had been done, as just after the initial tripping and my attempt at a re-start, the main transformer had been making alarming humming noises, presumably running on only two phases. Hence my concern :scratch:
So, switch on, power up the controller, home the axis's - all well so far - try and home the Tool Turret - cycle starts but never ends :bang: The dreaded Tool Turret :bang:
Actually it was simply an internal breaker that had tripped, presumably when 'two phasing' - reset it and all was well.
As a matter of interest I put my Fluke clamp ammeter on 'peak amps' - 90.5 for a very brief time, but usually about 20 per phase
Post by: awemawson on September 04, 2018, 04:57:54 PM
While I was in the measuring mood, I put the clamp meter on the DC armature drive cable from the KTK Mentor to the 27 kW Mawdsley spindle drive motor. 109 amps peak :bugeye: But well within spec
Then I measured the average on phase one of the 415 volt three phase input - only 18.8 amp - but peak 90 plus as above
Post by: awemawson on September 05, 2018, 02:23:59 PM
I'm getting tied in knots trying to set up tooling in Featurecam to match what I have and also to produce workable code, but there are just too many variable :bang:
Firstly, this is a single turret slant bed lathe, with the turret BEHIND the spindle - Featurecam details an Upper and a Lower turret, so I assume that the upper one is relevant.
Then (Obviously) the spindle can be programmed to turn Clockwise or Anticlockwise
Then tools can be Left Handed (LH) or Right Handed (RH).
Now the turret Tool Holders come in two flavours so that when using a LH or RH tool, the reference surface passes though the centreline of the turret to allow the correct tool height to be set, and for left handed tooling the spindle needs to rotate CLOCKWISE, and for (inverted)right handed tooling the spindle must rotate ANTICLOCKWISE.
Only the left hand version keeps the force downwards into the bed as in a manual lathe, but the turret and slide arrangement are so massive I don't think that this is an issue unless VERY heavy cuts are taken.
OK fairly simple so far, BUT, each tool in the Tool Crib is defined for CW or CCW rotation, and the M codes for these are embedded into the Post Processor, CW being M03 and CCW being M04
All well and good, but setting all these sensible values FeatureCAM has the spindle rotate in the wrong direction :bang: Easily changed in the Post Processor coding by swapping M03 & M04 but it's very odd to need to do it.
Having sorted all that, programming a normal right handed thread produces a left handed thread :bang:
Now I have a feeling all these oddities revolve around the choice of turret (Upper or Lower) - but as soon as I select the other turret the program refuses to allow me to pick the correct tool as it swears blind that the tool is intended for the opposite rotation - argh, my head hurts :scratch:
Have some tooling pictures
Post by: seadog on September 05, 2018, 02:35:07 PM
Post by: DICKEYBIRD on September 05, 2018, 03:12:55 PM
I know you British folks drive on the left side of the road but do your clocks run backwards :bugeye: as well?
Post by: awemawson on September 05, 2018, 03:54:00 PM
Seadog, the trick I was taught re handedness is imagine a pair of hands held in prayer. The tips of the fingers on the LEFT hand point right so that is a LEFT HANDED tool and vice versa - it works for me !
OK in Featurecam, using the UPPER turret, swapping the M03 and M04 around, and using inverted right handed tools for threading produces sensible code and right handed threads when asked for - but my head still hurts !
Post by: seadog on September 05, 2018, 04:00:22 PM
Post by: awemawson on September 05, 2018, 04:35:26 PM
. . . .more oddities . . :scratch:
I suppose it follows a mill spindle where the clockwise rotation being M03 is looking down the spindle.
Also if you think of a conventional manual lathe, top of the work comes towards you for 'forwards' and away for 'reverse'
. . . I'm more confused than when I started !
Post by: PK on September 05, 2018, 05:51:41 PM
Post by: DICKEYBIRD on September 05, 2018, 10:05:09 PM
Milton, maybe this IS a UK thing - googling does throw up several pictures of M03 being clockwise from behind the head stock as you say. But most certainly the Beaver is the other way round as is the Denford MiracSurely Beaver didn't convince Siemens to reverse the Beaver lathe control's spindle rotation away from the world standard M3/M4/M5 conventions just for their machine?
I work with British luxury vehicles every day and have run across some really strange things (to my American way of thinking) but in the end there's usually an ah-hah! moment where the engineers' logic soaks in & it all makes sense...sorta. :scratch:
What about you John/cnc-it...what say thee about this from your Beaver experience? Another British other-side-of- the road thing? :poke:
Post by: awemawson on September 06, 2018, 03:22:38 AM
I'm sure I'm telling you how to suck eggs, but I've re read your post and you didn't explicitly say that you would normally put tools in a rear turret 'facing down', ie the chip curls on the floor side of the insert, not the ceiling side. M3 is then clockwise from the rear of the chuck etc....
PK I chose to use mostly 'facing up' tools as a/ the lathe came with many of this style VDI 40 holder and only a few of the facing down type, and b/ the cutting forces are correctly down into the ways rather than tending to lift the turret.
From an operational point of view the only disadvantage is the way the chips fly, and it has the huge advantage of easy access to the tip for changing, and visibility whilst cutting is in progress.
But you might well be right that this is the root cause of my confusion !
The fact remains that M03 makes the chuck turn clockwise looking from the tailstock on this lathe
Post by: awemawson on September 06, 2018, 03:26:37 AM
Surely Beaver didn't convince Siemens to reverse the Beaver lathe control's spindle rotation away from the world standard M3/M4/M5 conventions just for their machine?
Milton, Siemens needn't have been involved - all it would take is to reverse the wires to the spindle motor armature, only two wires as it's DC. (The two from the tacho would also need reversing of course)
Post by: awemawson on September 06, 2018, 04:06:18 AM
Post by: russ57 on September 06, 2018, 05:52:12 AM
Russ
Post by: awemawson on September 06, 2018, 06:36:06 AM
Maybe it need time to cook :scratch:
I came across this paragraph in the Generation 2 commissioning notes - (NB mine is a Gen1) Of course they don't say the view point, but if the convention is to look from behind the chuck then it would confirm that as mine is set is intentional
later edit: I've just tried the YouTube video on the Wife's iPad (so that I'm not logged in) and it shows fine
Post by: seadog on September 06, 2018, 09:37:22 AM
Post by: awemawson on September 06, 2018, 09:51:32 AM
Post by: russ57 on September 06, 2018, 10:17:13 AM
Strange - it's marked as Public :palm:
Maybe it need time to cook :scratch:
later edit: I've just tried the YouTube video on the Wife's iPad (so that I'm not logged in) and it shows fine
I usually use tapatalk, no worries usually. But that video doesn't even appear as a link.
But it is there from the website...
Russ
Post by: awemawson on September 06, 2018, 02:36:34 PM
I'd not be a bit surprised to eventually find that this is tied to the M19 spindle orientation problem that I'm having. Diagnostically it might just be a blessing in disguise, but then it might just be a pain in the neck :lol:
This is supposed to be an M12 x 1.75 mm pitch thread !
Post by: charadam on September 06, 2018, 03:14:09 PM
Post by: awemawson on September 06, 2018, 03:51:05 PM
On the simulation it is distinctly Right Handed :scratch:
If you notice, the Z travel must be accelerating cutting from the chuck outwards as revealed by the increasing 'thread' spacing
Post by: charadam on September 06, 2018, 04:56:27 PM
I suspect that beetroot juice has got in the gigglilator sprocket and is confolunding the fundamole.
Post by: PK on September 06, 2018, 07:03:34 PM
Just to convince any doubters, myself included, here is a little video showing an M03 starting the spindle !:lol:
Maybe a previous owner bought a whole bunch of upside down tooling by mistake and then swapped the wires to the spindle motor to make their code work....
:poke:
Post by: awemawson on September 07, 2018, 07:10:30 AM
Someone please check my logic here:
A/ The program is cutting a normal right handed thread of 1.75 mm pitch, using an INVERTED tool located BEHIND the work and the spindle running
CLOCKWISE viewed from BEHIND the chuck
B/ This is exactly akin to a normal manual lathe configuration if you imagine the tool swinging round the work 180 degrees to be located in the normal
manual position in front of the work. Of course this movement has also cancelled the inversion of the tool.
C/ So as with a manual lathe, a right handed thread is cut TOWARDS the chuck, the tool withdrawing on the return cycle
So why, dear forum members, please tell me (to preserve my sanity!) is the tool engaged in the work on the travel AWAY from the chuck, and disengaged on the travel TOWARDS the chuck.
I closely monitored the threading progress, watching the controllers display of 'feed rate' - now when threading it is using 'G95 feed per rev' and the display shows 1.75R ie 1.75 mm per rev BUT it's showing this on the travel TOWARDS the chuck when the tool is DISENGAGED, and about 1000 mm per rev on the travel AWAY from the chuck when the tool is ENGAGED :bang:
So basically the tool X movement is reversed in this situation - but travelling to the beginning of the threading cycle it gets to the right place so is not reversed.
. . . argh . . .I need a coffee :coffee: :coffee: :coffee:
Post by: PK on September 07, 2018, 07:34:24 AM
If I'm right then it's a CAM thing....Is there an option in your CAM package for front or rear toolposts?
How does X work on your machine? not inverted?....
Maybe a different canned cycle or a parameter for rear posts in a machine controller able to cope with different machine configurations?
Post by: cnc-it on September 07, 2018, 07:40:06 AM
The Hitachi Seiki 4nE11 was this same configuration.
Post by: cnc-it on September 07, 2018, 07:42:08 AM
Post by: awemawson on September 07, 2018, 07:53:06 AM
The post processor is producing a positive depth of thread not a negative one. I have manually altered the produced program shoving a minus sign in and produced a decent thread.
I've not worked out yet why the PP is doing this - it might think it's doing an internal thread - I'll investigate after lunch
Post by: russ57 on September 07, 2018, 08:48:03 AM
Either that, or you have the southern hemisphere model...
Sent from my SM-G965F using Tapatalk
Post by: awemawson on September 07, 2018, 10:04:01 AM
I'm the furthest from an expert in cnc. But as someone suggested above, in absolute terms, the x direction would need to be reversed for a rear toolpost.
Either that, or you have the southern hemisphere model...
No Russ I don't think that is the case - remember that your frame of reference has rotated. Minus X travel is into the work piece in each case. In all cases the work piece diameter decreases as the tool approaches the axis of rotation.
So the test piece passes the 'will a nut fit' test with flying colours, and also the repeatability test.
As for altering the post processor, when the cycle for threading is generated, the PP doesn't know if it is threading internally (so positive thread depth) or externally (so negative thread depth) and I can't logically derive which case is in operation from the parameters passed from the program. You can't even enter a negative depth of thread where you define the feature, as it slaps your wrist!
One comfort from all this is I'm more than ever convinced that the M19 spindle Orientation issue has to be a software / enabling bit, as this threading is using spindle orientation at a great rate of knots quite satisfactorily.
All this testing is producing masses of swarf - I need to get the covers back asap not only to contain it, but also to allow me to use coolant.
Post by: mc on September 07, 2018, 11:03:45 AM
All this testing is producing masses of swarfSurely a smaller bit bar, or a bigger nut would reduce the masses... :)
Post by: awemawson on September 07, 2018, 11:18:59 AM
Post by: awemawson on September 08, 2018, 06:26:47 AM
After finding that, it was a simple matter of multiplying the thread depth <THRD-DEPTH> by -1 for external threads, and the problem was solved. Dead easy in retrospect, but it took a while !
Post by: cnc-it on September 08, 2018, 07:16:05 AM
Post by: awemawson on September 08, 2018, 07:30:18 AM
That's why i like Featurecam..editing posts is really easy..the whole cam package is built with machinists in mind :thumbup:
Yes but sometimes the syntax gets overly complicated !
Post by: cnc-it on September 08, 2018, 09:31:07 AM
Post by: awemawson on September 08, 2018, 09:58:47 AM
Post by: cnc-it on September 08, 2018, 12:24:36 PM
Post by: PekkaNF on September 09, 2018, 06:19:15 AM
Siemens Simatic S5 PG 675
(https://upload.wikimedia.org/wikipedia/commons/thumb/7/74/Siemens_Simatic_S5_PG_675.jpg/640px-Siemens_Simatic_S5_PG_675.jpg)
Pekka that's EXACTLY the device with Step5 software that I need to read my Symatic 820T PLC ladder
We had least 20 extra PG675/685 in the storage, probably few left after premises were downsized. Engineers still have access to S5 with modern laptops (serial to current-loop adapter + programming program). That program is proverbial to install and update.
Old PG.s were pretty much bulletproof. Only problem was that cooling fan was not good enenough on some models and if you were in hot environment, the filter had to be removed or PG would die. Removing the filter has it's own set of complications - you don't want the PG to sit on dirty floor.
There was a luggable PG, used it anly a little time, never needed to touch the OS or S5 programming program. When we swiched to laptops there were more to worry about, starting from the physical connection (RS-232 to curren-tloop converter) and Siemens changing "sopy protect bit" and such too often and needed a certified excorcist to banish gremlings out of systems I lost interest and stopped working on them. Although S5 did beat the contemporary A-B, Telemecanique, AEG and ABB systems if you had over 2000 discrete I/O:s and some high speed counter/analog controls. Even simple timer functions were pretty advanced compared to other system. FB:s were black magick even when you have source code if you had no idea what they were trying to accomplish.
System was that plentiful, that I would imagine they are available e-bay.
Pekka
Post by: awemawson on September 09, 2018, 08:42:13 AM
I reckon it's time that you came over for a Holiday in the UK, I'm sure we can find a slot in the calendar for our holiday cottages. Borrow a colleagues STEP5 laptop and come and have a play
Objective: get a hard copy of the PLC ladder
Bonus: a free holiday for you and yours
A true win win solution :clap:
https://www.cottages.com/cottages/lower-marley-farm-apple-cottage-27442
https://www.cottages.com/cottages/lower-marley-farm-quince-cottage-27443
Post by: PekkaNF on September 09, 2018, 08:52:42 AM
Pekka
Post by: awemawson on September 09, 2018, 09:02:17 AM
Looking on eBay you are right there are several on offer, but I'm not sure what I'm looking at as not a German speaker. The extra programmer unit is also available. I don't mind buying one so long as I don't choose the wrong thing in my ignorance. Any tips appreciated.
Were they all CP/M 86 based. I cut my teeth on CP/M with home brew Z80 / S100 systems and 8" floppy drives :lol:
An alternative is somehow to get STEP5 on a laptop. I revived a Toughbook running XP only yesterday to see if it's battery was any good, as it has a proper serial port.
But all my attempts so far to source a working and enabled STEP5 have come to nothing, all very frustrating.
Post by: PekkaNF on September 09, 2018, 10:32:01 AM
You are right, the old ones were CP/M, but OS was used mainly to copy discs, BU-files and very basic stuff. Everything to do with Siemes was on that all encopasing programing program. Maybe here is one obsolote, but operational unit floating somewhere. Have to ask, hopefully my mailbox is not litterd with URGENT-messages on Monday - I might even remember it until lunch:)
Pekka
Post by: awemawson on September 09, 2018, 11:11:29 AM
Presumably with the right software PG 675 / 685 / 720 or 740 would work ?
Post by: David Jupp on September 09, 2018, 01:57:15 PM
Our process control guy had a luggable Siemens PC (yes I mean an IBM PS2 compatible) to talk to the PLC- I don't remember clearly, but i suspect it was DOS based (1990s). 3.5" floppy drive.
Post by: PekkaNF on September 10, 2018, 05:53:22 AM
1: First problem is the physical: The current loop dongle works only with real RS-232 serial port, docking stations do not support it. There is a rumour that one USB-dongle worked with it, but newer models don't. Even when they state they do.
2: Windows version. S5 aplication programs are very old. Basically if you need to program EEproms (or even Eproms) for cumminacion cards etc. it's nearly no-go. They have one ancient PC from someone's home that runs with all those programs. There were some laptops that run the old programs and were used, but I.T. tries to hunt them down and confiscate (security risk, old operating system, danger of connecting them into internal network......). Situation has got worse from 2013 after big downsizing/move.
Do you have the cables and serial to current-loop converter + all the cables?
I'm going to ask someone I'll meet later this week what are they useing to connect obsolote S5, I know we have the projects and least some of them would benefit greatly if there were a way to connect to live PLC and see what is actually running and what I/O is being adressed (after 20 years of use and countless rebuilds mills tend to add some aux controlls to closest available PLC and much joy if the sump pump or extreaction fan is disconnected permanently).
I am sorry about the bad news. I wish I had stached some of the stuff they trashed 5 years ago.
Pekka
Post by: awemawson on September 10, 2018, 06:57:28 AM
What i don't have is the software, the dongle, or the cable. No doubt the RS232 to current loop can be sorted relatively easily.
As an alternative I am watching this on eBay :
https://www.ebay.co.uk/itm/Siemens-6ES5675-0UA11-Simatic-S5-PG675-Programmierger%C3%A4t/113100786538?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
But I'm not sure if those two floppies represent all the software that is needed.
Also I am following this programmer, which I think is the correct one:
https://www.ebay.co.uk/itm/Siemens-6ES5985-2AA11-MEP-Module-Eprom-Programmer-for-PG-675-E-Stand-2/391926287016?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
BTW thanks for remembering :thumbup:
Post by: PekkaNF on September 10, 2018, 08:05:46 AM
1: Cable from PC RR-232 to converter
2: Wall wart for converter and converter
3: Cable from converter to PLC, there were least two types one D15 and one D25
Something like these:
https://www.ibhsoftec.com/epages/63444704.sf/en_GB/?ObjectPath=/Shops/63444704/Products/2042
I remember working with U115, U135, and U155 CPUs. Sometimes we had to solder the cables, when they got lost, broken or worn. I think the currentloop converter was internaly fairly simple affair like two optocouplers, resistors to set the current and constant current source. Something like this:
(http://www.plctalk.net/qanda/uploads/TTY_S5.jpg)
*bit more google, I don't rememenber seeing these, but I could be the right thing*
https://www.ebay.co.uk/itm/New-6ES5-734-1BD20-Programming-Cable-For-PC-TTY-PCTTY-Siemens-S5-PLC-/141723080984
I am not sure if the floppies are reliable after all these years, least I can't open the files from the floppies I had from that time. Still more reliable than 3.5".
This is how the boot looks like:
PG 685 would have a HD and all programs on that one. Darn. Now when I think of it, I have forgot most of it. There some other like PG 740/750.
You really have a knack of finding a challenge.
Pekka
Post by: awemawson on September 10, 2018, 04:15:48 PM
It consists of four elements:
An MI12 'Machine Interface' - (A box that talks to the Siemens control and the OMM )
An OMM (Optical Module Machine - machine mounted infra red sender receiver )
An LT02 (Tool Turret mounted infra red sender receiver)
An LP2 that mounts on the LT02 (a sensitive switch operated by a probe touch)
What is supposed to happen, is that the MI12 tells the OMM to 'wake up' the LT02 as it has an internal battery that needs preserving. Once awake, if the ruby probe tip trips the LP2 switch element, the LT02 transmits a signal to the OMM, which passes it to the MI12, which gives a signal to the Siemens controller that we are in contact.
Post by: awemawson on September 10, 2018, 04:24:08 PM
Now there was no apparent response from an LT02 held in range and triggered. So maybe the LT02 is faulty, or maybe the OMM is not receiving ?
So today's task was to dismount the OMM and have a look at it's electronics and see if I could glean any further information. Not the easiest thing to get at, being behind the machine sliding door, but just possible.
The wires are pretty delicate and extremely short making the job an utter joy !
First the outside glass cover has to come off, and a shroud, giving access to the wiring terminals. To get a bit more space to move, I took the OMM off it's mounting bracket.
Post by: awemawson on September 10, 2018, 04:47:26 PM
Now what I wanted to do was prove that the IR receiver part of the OMM was (or was not) working. Using a remote control from an LED Floodlight, I clamped one button 'pressed' , arranged it to point at the OMM IR sensor, and poked about in the circuitry with my 'scope probe. Now much of the electronics near the IR sensor is covered by screening cans that are not easy to remove, and it's all a bit tiny being surface mount. However I did find responses to the IR signals that I was sending, so the IR diode must be working.
I then went to the other end of the electronics, where a DS8921M differential line driver talks to the MI12 - no output, and also no input. Now between where I found the response, and this chip, there is more hidden circuitry that I can't get at. But I don't think that there is anything sophisticated enough to be decoding signals, just buffering and level shifting. This is where the relevance of that wake up signal comes in. If the designer put the clever bit of the wake up signal back in the MI12 unit, he probably did the same for the touch received signal (maybe !!!!)
On the board are two miniature LM7805 5 volt regulators (that are working) and an ICL7660 switching voltage converter that is producing a -3.5 volt negative rail, but I have no idea if this the the 'right' voltage of course.
So in conclusion, it's inconclusive :bang: The IR diode is working but I still don't know if the OMM or the LT02 is the actual fault !
Really I need to find another machine equipped with this system and wave my LT02 at it's OMM!!
In the end I put it all back together and took the dogs for a walk !
Post by: PK on September 10, 2018, 05:37:21 PM
PK
Post by: awemawson on September 10, 2018, 05:56:43 PM
Your response has prompted me to look very closely at the photos I took at the time.
I've spotted what looks to me to be an exploded surface mount capacitor - if it's the same as others on the board it should be 33uF at 16 volts - certainly doesn't look healthy
Of course it's all back together now :bang:
Post by: PK on September 10, 2018, 10:08:28 PM
Anything more than a few hundred mV is bad.
Post by: cnc-it on September 11, 2018, 04:29:01 AM
Post by: PK on September 11, 2018, 09:34:51 AM
PK
Post by: awemawson on September 11, 2018, 10:09:31 AM
The cabling for this device is ridiculous. The MI12 sits in the hydraulic cupboard under the controller where there is a 24 volt supply, but the MI12 takes it's 24 volts from a cabinet at the diagonally opposite (rear) corner, with the cable draping all over the place and passing through ungrometed holes. The MI12 to OMM cable goes round three sides of the machine to join front right to front left, with the same draping cables. When it's working (if?) there will be a re-routing exercise.
It was obviously an 'upgrade on site' and of course although I have all the panels off at the moment, the chap who installed this didn't, so it's easy to be critical unjustly. :scratch:
Post by: awemawson on September 13, 2018, 05:53:33 AM
So rather than dis-mount the OMM and find that I'd cocked up the order I thought I'd try and scale the size from the photographs knowing the size of an 8 pin SOIC IC (which was in the same frame)
Turns out these 33 uF caps need to be between 6.7 and 8.5 mm long, whereas the ones I ordered are only 4 mm long :bang:
Never mind, better to find out now rather than when the thing is in bits on the desk stopping everything else while waiting for parts. So another order sent off, and this time (plonker before didn't!) I checked the physical size - 7.3 mm long in this case - should arrive tomorrow
. . . hey ho . . onwards and upwards
Post by: PK on September 13, 2018, 08:30:38 AM
Post by: awemawson on September 13, 2018, 08:58:51 AM
(Although I do have a hot blower as part of my de-soldering iron I suspect I'll just use a very fine tip for this capacitor)
Post by: awemawson on September 14, 2018, 07:57:27 AM
Capacitors arrived and sure enough they are the right size this time, so I removed the OMM from the machine, dismantled it and removed the circular PCB. Hey guess what that's NOT an exploded capacitor - it's a blob of paint :bang: :bang: :bang:
Never mind, couple it up to a 10 volt bench supply and do some more testing. PK's tip about the ICL 7660 chip is very interesting. It takes in +5 volts and apparently should 'mirror' this to provide a -5 volt rail, whereas it's producing -3.5 volts.
I identified the two capacitors that it uses to perform this magic (68 uF @ 6 volts), and following PK's tip that they might be low capacitance tried paralleling them one by one with a 22 uF capacitor - it made not a jot of difference. So probably PK's other suggestion of it being over loaded is the case :scratch:
Now much of the circuitry of this PCB is hidden under a screening can, and to progress it's going to have to come off. Only held down by seven through PCB tags neatly soldered on a very crowded small PCB :bugeye:
Digging out my 'electric pump' de-soldering sucker it looked ridiculously big compared to the PCB, but with a delicate touch, a bit of flux, and adding some low melting point solder to the last persistent lug eventually got it off with no apparent damage.
Now I was rather fearful that the cover might conceal some encoding / decoding logic but in fact it all seems to be analogue OP Amps comparators etc so the full chip count is as follows:
Reverse Side:
LM78L05 (2 off): +5 volt regulator
ICL 7660 : Negative rail generator (should be -5 is -3.5)
LM393M : Op Amp / Voltage comparator
DS8921M : Differential output driver (gives SIGNAL and
Plus 3 off SMD transistors
On the Front Side (under the screen):
OSD 15-3TRB : IR receiver
LM833 (2 off) : Audio Op Amp
LM311M : Voltage Comparator
AD848 : High Speed Op Amp
Plus 4 off SMD transistors
On the front side (not under the screen) ZTX 450 discrete transistor
To go much further I'm going to have to make a rig to mount the circuit so that I can safely probe it without doing damage, and also to make up an IR transmitter that sends a train of pulses so I can trace through the circuit.
If indeed one of the circuits is pulling down the -5 v it's going to be a pain to find as the LM833's, the LM311, The AD848 and the LM392 all take the negative rail voltage.
Won't be much more progress today as I have to play host to some guests arriving this afternoon.
Post by: awemawson on September 14, 2018, 09:01:53 AM
Post by: awemawson on September 15, 2018, 03:36:24 PM
&t=2184s
Post by: awemawson on September 16, 2018, 07:30:38 AM
I hit on the idea of looking at the board with my infra red thermometer - now it's by no means easy to be sure exactly where it is pointing, but looking at each integrated circuit the hottest was the ICL7660 - not surprising as we know it's probably over loaded. (I think that it can supply about 20 mA) - it was running at about 39 degrees whereas the other ICs are at about 26-28.
But scanning the board in general one of the capacitors was running at over 40 degrees - is this our trouble maker? It's the 68 uF / 6 volt one next to the famous one with the paint blob and is the one used by the ICL7600 to do the voltage inversion.
It's position on the PCB and (relatively) large size allowed me to remove it with a fine tipped soldering iron and substitute an axial one for testing.
. . .so what was the result, nothing, zilch, nowt - voltage remains at -3.5 :bang:
Never mind, it was a good idea. Carefully put the SMD capacitor back and scratch your head a bit more :scratch:
Now if this was a conventional sized board with DIL I/C's I'd carefully lift the -VE rail input legs on the I/C's one by one and monitor the voltage on the negative rail to see who's causing problems - not really possible at this scale.
Another technique is to construct a probe with two very sharp tips close together but insulated from each other, and with it connected to a sensitive millivolt meter, probe the PCB tracks leading to the supply pins in question. The tracks have a finite (but very low) resistance so a small voltage is developed across the probes that is proportional to current. Brilliant in theory but not too good at this scale as you can't really get at the PCB tracks.
. . . a bit stumped at this stage :scratch: :scratch:
Post by: russ57 on September 18, 2018, 08:07:27 PM
Russ
Post by: awemawson on September 19, 2018, 10:45:32 AM
Yes I had considered that but I'm scared to do more damage. I've dug out a x20 microscope and have been looking round the circuitry, but it is very confusing - the SMD markings are rather coy about what they really are - I have found a document that helps somewhat in the translation (attached) and I have found what appears to be a transistor type 5B (MMBT4123) that seems to be s/c base / collector. It appears to buffer the output of one of the LM833 op amps.
Now I'd like to just remove it and / or the LM833 but these things are sized like a grain of rice and I'm just not equipped for this size of component -
I did seriously consider getting myself a hot air re-work station, but even if I did, I don't have the skills working at that scale :bang:
. . . time for a re-think :scratch:
oops - the .pdf was too large have a link instead:
http://www.marsport.org.uk/smd/mainframe.htm
Post by: Pete. on September 19, 2018, 01:36:15 PM
Post by: awemawson on September 19, 2018, 01:40:41 PM
Post by: mc on September 19, 2018, 02:27:20 PM
Key thing is good fine tipped tweezers, as they make positioning components far easier.
Also suitable solder paste and dispenser make fitting bits far easier. I don't mind building SMD boards, but the fact good solder paste is so expensive compared with ye olde solder wire, and it goes off, means I try and avoid using SMD, but some times it's unavoidable.
Post by: awemawson on September 20, 2018, 06:15:26 AM
Very many thanks to PK who is definitely a 'good chap' as I was going cross eyed chasing this problem :thumbup:
Post by: DICKEYBIRD on September 20, 2018, 10:15:56 AM
Well PK has VERY kindly offered to take a look at this unit as I understand his company has the suitable facilities, so it's started on a long journey to the other side of the world this morning on a '5 day target' service from the Royal Mail.Another example of "It's not what 'ya know, it's who 'ya know!"
Very many thanks to PK who is definitely a 'good chap' as I was going cross eyed chasing this problem :thumbup:
Post by: awemawson on September 20, 2018, 11:33:32 AM
:mmr:
Post by: kayzed1 on September 24, 2018, 04:09:10 PM
Lyn.
Post by: awemawson on September 24, 2018, 04:21:22 PM
The OMM pcb has left these shores and hopefully will arrive in Oz any day soon :thumbup:
The M19 spindle orientation issue is still eluding me. Contacts on the Siemens support forum assure me that it's just a option that needs enabling by setting a 'bit' but which bit !
I have obtained a full back up from a Beaver TC10 lathe that DOES spindle orientate using M19, and I've been through the files byte by byte comparing them with mine trying to account for differences. However nothing yet shouts at me saying 'It's ME !'
. . . madness beckons :clap:
Post by: awemawson on September 27, 2018, 02:34:57 PM
M20 (which enables the servo / closes the loop for spindle positioning)
M19 S180 (which should do the actual motion.
Well, it turns out that the M20 is setting the correct bits in the PLC (Q100.6 & Q100.7) for loop enabling, but then putting the 820 Control into ' STOP:READ-IN ENABLE' . This prevents the control reading the next instruction (the M19) hence the control 'hanging'
Now poking around in the PLC documentation 'QB87 bit 5' is apparently the 'Read-In Enable' bit, and sure enough before the M20 is executed it is 'true', but once the M20 runs it goes low (false) preventing the next instruction being read.
As I understand it, for testing I should be able to force it back to true to see if the M19 works, but it resolutely stays as a '1'
Sorry if this all sounds somewhat arcane, but getting it down helps me sort it out in my head - well it should, I'm not there yet :bang:
I strongly suspect that the back up copy of the PLC program is corrupt.(*) I do have a copy from the other lathe that I got back ups from, but it is only 6K long whereas mine is 18K, probably as my lathe has gear changing built in with the PLC doing the clever bits to prevent gear crashing - I'm not at all sure it's safe to load the shorter version, even for testing :scratch:
(* an alternative theory is that perhaps a bit of memory that the PLC program sits in is faulty :scratch:)
. . . as before . . . madness beckons :med:
Post by: awemawson on September 28, 2018, 05:45:29 AM
Thanks PK :thumbup:
Post by: PK on September 28, 2018, 06:50:51 AM
Next we took a look at the negative voltage reg. It is used to generate -5V for the amplifiers and comparitors under that shield.
(http://www.soledigital.com.au/images/personal/andrew/7660.jpg)
It looks like the 6.8uF cap on the screen is the output capacitor for this reg. It isn't, it's a 68uF cap a bit further away. This was removed and replaced but the voltage was still low.
The reg chip was removed and replaced, and the voltage dropped a bit lower to 2.7V! I guess they don't make 'em like they used to.
I lifted the output pin and connected a small cap to ground and the voltage shot up to 4.9V So it's probably something overloading the reg.
Out came the thermal camera (and yes, I forgot to snap a pic) and one chip in particular was running quite a lot hotter than the others. An LM833 audio amp. Now this may still be a red herring, as audio amps sometimes run hot, and often drive low impedance loads... In any case, it was asked to leave the premises and we now have a -4.7V rail.
(http://www.soledigital.com.au/images/personal/andrew/833.jpg)
I think we'll just order every chip on the board. There's no unobtanium in this thing...
Oh, and if all this talk of ripping components off expensive PCB's generates anxiety. Don't worry, it's not my PCB.. :thumbup:
Post by: Pete. on September 28, 2018, 06:55:43 AM
Oh, and if all this talk of ripping components off expensive PCB's generates anxiety. Don't worry, it's not my PCB.. :thumbup:
I could really like this guy :) :) :)
Post by: mc on September 28, 2018, 06:57:42 AM
Oh, and if all this talk of ripping components off expensive PCB's generates anxiety. Don't worry, it's not my PCB.. :thumbup:
Now that's the kind of attitude I like! :D
Post by: awemawson on September 28, 2018, 07:23:54 AM
. . . but progress - good stuff. Look at the smd transistor that has an arrow scratched pointing at it on the semi-circular trace that the can sits on - that's the one that looked to be s/c collector base, but it could be the op amp it's connected to which is an LM833
That's an impressive magnifying set up that you have there :thumbup:
Post by: PK on September 28, 2018, 08:19:06 AM
I kinda suspect there are two faults. One with this negative voltage rail, and another with the probe. I'd expect to be able to see some activity from the IR LED on the probe when it see's the start signal, looking at it with a webcam or phone being just a repeat of your tests..... I'll have a sniff around the photodiode on the TX board tomorrow with a 'scope, just in case the response from the probe is on a wavelength that isn't detected by our cameras. All whilst pondering the best way to get into that probe without screwing up the waterproofing..
PK
Post by: awemawson on September 29, 2018, 05:03:40 AM
Post by: awemawson on October 02, 2018, 03:17:57 PM
I wanted to get the wiring in existing trunking while the lathe cabinet sides are off, and wire the MI-12 interface via plugs and sockets. It needs a 24 volt supply from the main I/O supply in the rear cabinet (2 wire plus screen), an output to the appropriate card in the Siemens 820T controller (again 2 wire plus screen) and a multi-core to the OMM that PK has on the other side of the world (5 wire plus screen)
I chose XLR style connectors as I already had two of the three, arranging that the 3 pole ones were opposite gender to prevent them being able to be confused.
Initially I'd intended to mount them on a bit of the trunking in the cabinet where the MI-12 sits, but then decided that it would actually be easier to mount them in a separate box which then could be fixed to the trunking as an independent item.
So, first let's see the problem
Post by: awemawson on October 02, 2018, 03:25:24 PM
I used 2 mm plate, in retrospect I think that this was a bit OTT, and 1.5 mm would have been a better choice as it would have bent more crisply in this small size, but it's come out OK
Having cleaned up the cut profile with a sanding disk, and made sure that the connectors fitted their odd shaped holes, I then bent it up, and soldered the corners. After a bit of a clean up it got a coat of zinc rich paint followed by a coat of satin black.
So it's now all ready to fit - I will probably run new cables rather than disturb the old at this point, as when the OMM returns I don't want the uncertainty of replacement wiring muddying the waters when it comes to testing - anyway the existing stuff is a bit mangled in places (although intact)
Post by: awemawson on October 04, 2018, 11:24:11 AM
Anyway this one was just about affordable, and it was from a dealer that I'd actually bought parts from before when I was breathing life back into the Traub lathe. Why do you need another CPU card? Well probably I don't and won't, but if I do you can guarantee the only ones will be priced in telephone numbers ! The real reason though was that there is just a faint possibility that the M19 / M20 spindle orientation issue could be CPU based, after all it not only is running the code and handling the interrupts, but also has some of the RAM on board. So as a diagnostic aid, and then ultimately as a shelf spare it was worth it.
So today (having paid the VAT etc on line yesterday) Parcelforce in the shape of Adrian our local man, delivered it. With no more ado I pulled out the original CPU card, put in the new and fired up the machine - ah well no - she's NOT firing up. Oh blast - dead on arrival - never mind - Paypals' 'pay after arrival' has it's uses I thought.
Original CPU card re-installed - oh HECK - shes's not firing up - it's blown something up. :bang:
No, calm down chum, there's RAM on the card, is that part of the battery backed parameter stuff? Sure enough pressing the magic 'Eye' key on the controller when powering up got me into the re-load 'Initial Clear' mode - perhaps it's NOT D.O.A. after all. So new CPU put back in, and again into the 'Initial Clear mode by pressing the Eye key, and I started the long winded rigmarole of reloading all the back up files.
I'd just got to a critical stage when the wife needed urgent help - sheep issues - (there are always sheep issues!) - one with 'fly strike' - one limping - loads of carrying hurdles about, penning up sheep and getting thoroughly filthy - actually it was a nasty fly strike occasioned by a partially torn off horn and consequent blood on a Jacobs lamb and did need urgent treatment.
OK - wash the maggots off my hands and get lunch :bugeye: (ham omelette) then back to the re-loading of the controller. All went OK, all functions work except of course the M19 /M20 spindle orientation. It was a pretty faint hope, but at least the CPU card has been eliminated and now I have a shelf spare.
Post by: awemawson on October 04, 2018, 12:28:52 PM
It looks as though I had miss-understood the instructions, which seem to be a translation of the original German, into Russian, then into English. Anyway cutting a very long story short, I have managed to get some form of STEP5 running on my Panasonic Toughbook CF-52 under Windows XP-Professional.
The CF-52 has a proper serial port, but there lies my next hurdle. I can't find any way of setting up the communications parameters in STEP5 let alone set up the 820T controller to know that it has a PLC monitoring program on the other end of it's RS232 cable !
I can see some considerable googling happening this evening and rather a lot of :coffee: and :scratch: and more :coffee:
Post by: Pete. on October 04, 2018, 03:17:45 PM
Post by: awemawson on October 04, 2018, 04:09:42 PM
The real issue at the moment is getting STEP5 to know about ANY interface, never mind the wrong one! I suspect that possibly there are some windows drivers needed. The port on the CF-52 exists, XP-Professional knows it's there, and I've used it to talk to the 820T controller for loading and downloading.
The STEP5 program is very 'DOS Looking' and I think thereby lies the issue !
Post by: awemawson on October 04, 2018, 04:21:08 PM
Post by: awemawson on October 05, 2018, 06:34:25 AM
At last I've found the bit in STEP5 that lets me select the correct COM port (COM2: on this laptop) - now the book of words for the 820T controller doesn't directly refer to STEP5 talking to it's interface, but it does refer to "PD/PG Programming Workstation" and gives me parameters for the interface (4800 baud, 8 data, 2 stop bits, no parity, flow control via XON/XOFF) and gives a 'device code 3' in the setting bits so the controller knows what it's talking to. What it doesn't say is what I need to do at the controller to start the two talking ! At the moment I've just experimented in the 'data-in start' mode.
Using XP's Device Manager to set the COM port to match and thrashing about again in STEP5 I find a bit where the PLC can be set ONLINE from it's current 'OFFLINE' state. If I do this it give me a message saying that it's checking the interface, but then comes up with a red error message "System Message no. :0334"
Is this progress - yes I think that it is of a sort - the STEP5 program is at least acknowledging that is has a port to talk to but presumably doesn't like what's being whispered in it's ear !
The major issue is that I have no documentation for STEP5 and haven't so far been able to find a source.
. . these things grind VERY slowly . . . .
Post by: AdeV on October 05, 2018, 06:45:01 AM
Top hit is probably useless: https://support.industry.siemens.com/cs/document/18548070/-system-message-no-0334-when-attempting-to-go-online-with-step-5-v7-2-in-windows-xp?dti=0&lc=en-WW
However... it's possible that XP isn't letting STEP5 have direct access to the COM ports, especially as it does (as you say) look a LOT like an old DOS program. How lucky do you feel? Maybe you could wind the clock waaay back & try a Windows 95/NT4, or even Win 3.1 setup? Possibly in a Virtual Machine, although that might muddy the waters even more...
Post by: awemawson on October 05, 2018, 06:52:46 AM
I've been searching for the manual for 'step5 V7.23' without any luck, but I HAVE just found (all 529 pages!) of the V7.0 manual. Now no doubt there will be many differences, but at least it is shedding a bit of light on things !
Post by: AdeV on October 05, 2018, 06:55:12 AM
Another possible issue to head off at the pass, are you running a multi-core CPU? If so, you may need to restrict it to a single core...: https://support.industry.siemens.com/cs/document/44044935/how-do-you-avoid-a-blue-screen-when-using-step-5-v7-23-for-an-online-connection-between-a-pc-with-multi-core-cpu-and-an-s5-?dti=0&lc=en-WW
Post by: DICKEYBIRD on October 05, 2018, 06:55:23 AM
Post by: PekkaNF on October 05, 2018, 10:15:36 AM
Pekka
Post by: awemawson on October 06, 2018, 05:22:17 AM
a/ Prove the COM2: port on my laptop is working
b/ Prove that STEP5 is talking to the correct COM port
c/ Make sure that the baud rate, word length, parity and flow control all match
So by connecting my trusty RS232 breakout box using the same cable that I've been using to try and talk to the PLC, going to the command prompt under WIN-XP-Professional and issuing the command:
COPY CON COM2 (copy blocks from the CONsole to COM2:)
Sure enough I get activity on the transmit line - good, the port is working OK
Now here comes the oddity. If I use the MODE command to show how the port is set up I get 1200 baud, no parity, 7 data bits, 1 stop bit Xon/Xoff disabled and DTR/RTS enabled. But I have set it in Device Manager to be 9600 baud, no parity, 8 bits, 2 stop bits, using Xon/Xoff - see the picture with both on the screen at the same time !
So what happens if I run STEP5 with the port connected still to the breakout box? There is transmit activity - STEP5 IS talking to the correct com port :thumbup:
But look what happens to the port settings - under MODE we now have the correct baud rate, but wrong parity and flow control but under Device Manager everything is correct :scratch:
And if I bring up Device Manager and the Command Prompt screens while STEP5 is running they still contradict each other :scratch:
Another oddity is that I cannot get the MODE command to accept a setting for Xon/Xoff - I must not be understanding the syntax despite having the crib sheet on screen by entering mode /?
So something odd going on here - until I can get consistent port settings the PLC ain't going to talk ! Who is controlling this port ????
Post by: AdeV on October 06, 2018, 06:43:01 AM
Code: [Select]
MODE COM3: xon=on worked for me...
Interestingly, I have mis-matched port settings in Windows 7 as well.... although this laptop doesn't have a real serial port, I wonder if Windows & "DOS" are somehow talking to different things?
Post by: AdeV on October 06, 2018, 06:56:20 AM
Post by: awemawson on October 06, 2018, 07:44:32 AM
Post by: awemawson on October 06, 2018, 08:47:05 AM
This mode thing is VERY odd. If I use your syntax as a single parameter sure enough I can enable XON but not as one of a line of parameters.
If I set baud rate, no of data bits and parity as a mode command then follow with mode com2: xon=on as a subsequent command it sets XON ok but resets the bits back to 7/1 leaving the baud rate at 9600 :bang:
Post by: seadog on October 06, 2018, 10:18:55 AM
MODE COM2: 9600,n,8,2 should do the trick.
Post by: awemawson on October 06, 2018, 10:47:09 AM
And with your command line it reverts to RTS & DTS with XON disabled but does set the baud rate etc OK as shown in picture 2 above where that is the mode command that I issued !
It wasn't until I looked at that picture I realised it actually told me what it was defaulting to !
Post by: seadog on October 06, 2018, 12:34:58 PM
Post by: russ57 on October 07, 2018, 04:48:32 AM
Serial port: MODE COMm[:] [BAUD=b] [PARITY=p] [DATA=d] [STOP=s] [to=on|off] [xon=on|off] [odsr=on|off] [octs=on|off] [dtr=on|off|hs] [rts=on|off|hs|tg] [idsr=on|off]
IE
Mode com2: BAUD=9600 PARITY =e DATA=8 STOP=1 xon=on
Russ
Post by: awemawson on October 07, 2018, 09:46:34 AM
Yes that works and not only can I set the correct bits, baud rate and parity using Xon, but it actually remains unchanged having been into STEP5 and then out. I can't use the MODE command when actually running STEP5 as MODE complains that that port isn't available of course.
Today's plan was to connect up my Tektronix 834 RS232 analyser and try and watch the traffic between STEP5 and the 820T controller, having firstly re-taught myself how to use it after many years gathering dust.
First - set up it's interface to match the laptop - COPY CON COM3: and sure enough 'THE QUICK BROWN FOX . . . .' ends up on the analyser screen.
Next - connect the 834 to snoop on the line - now this requires a three way D-Type cable IDC cable. Male at one end (for the 820T), Female at the other (For the STEP5) , with a Male in the middle (to connect to the 834 Analyser). I used to be awash with these, and also the IDC plugs and sockets to make them - always useful on site to make up odd connections to printers, modems etc. Could I find one - of course not :bang:
OK lets see what STEP5 is sending out on the interface even if we can't see what does or does not come back from the 820T controller as this just needs a simple male / female cable.
Answer: STX NULL BRK NULL BRK STX NULL BRK
So what did I learn from that? Not a lot except that presumably it's polling the control and waiting for a response, then not getting what it expects it times out.
I still don't know what mode or state the 820T controller needs putting in for all this exchange to work. I've been assuming it needs to be in the Input/Output mode waiting to receive, but that is just guessing. But at least thanks to Russ the mode issue seems sorted.
Order for D-25 IDC plugs and sockets placed with RS-Components - should be here Tuesday :ddb:
Post by: russ57 on October 07, 2018, 05:57:46 PM
Perhaps an ACK or CR
doesn't help with getting the controller to the right mode but perhaps at least confirmation that step5 is happy.
Russ
Post by: awemawson on October 08, 2018, 08:37:04 AM
(Distracted this morning trying to get a two tube U/V fly killer working for the meat preparation area. How simple can they be, two little 300 mm T5 fluorescent tubes, two 115 volt starters, one 240 volt choke, one 240 / 2200 volt EHT transformer, two interlock microswitches. At any one time I could get one tube working but not both, and every time I switched on it was random which one started. EVENTUALLY realised that someone has fitted two 15 watt tubes whereas they should be 8 watt ones according to the choke markings.Tubes in series hence the odd symptoms :bang:)
Later Edit:
Russ, it looks like it IS possible but rather complicated. I'll wait until I have the three way connection, hopefully tomorrow.
Post by: russ57 on October 08, 2018, 06:56:51 PM
Russ
Post by: awemawson on October 09, 2018, 04:30:15 AM
Patience always helps!
Russ
Patience isn't one of my virtues Russ :clap:
Still waiting for the IDC connectors, though tracking says 'out for delivery today' :thumbup:
Also still waiting for the correct fly killer tubes, but I left it on the workshop bench overnight running one tube (due to the wrong tubes) and it's amazing how many flies it's zapped - over a dozen :bugeye:
Post by: awemawson on October 09, 2018, 08:20:10 AM
So, cable made up, Tektronix 834 and Sinumerik 820T steamed up and interconnected to my Toughbook CF-52 running STEP5, and full of expectations I told STEP5 to go on line.
. . . result ? . . nowt, no response what so ever, the 820T sits there like a sulky child doing the dumb insolence thing :bang:
In desperation I set the interface to use RTS/ CTS and then DSR/DTR but no, still no response at all although the controller was happy to push out its same polling sequence
This is getting very frustrating, there are just too many variables.
. . . meanwhile the dead fly count is increasing at an alarming rate - I think that there must be a dead pigeon on the roof :scratch:
Post by: awemawson on October 09, 2018, 11:57:00 AM
Thanks to a user (Pea Ell Sea) on the Siemens support forum I've found that the value for parameter #5010 needs to be 00000100. This value of 4 brings up "PLC-Prog" on the Sinumerik 820T input screen and the STEP5 program goes 'online' and reports PLC Type as S5 135 PLC.
One hurdle surmounted after days of trying :ddb:
The next mountain to climb is to learn more about STEP5, so that I can have a look at the PLC program and hopefully see things in real time.
Decided not to plough on immediately in case I break something - take the dogs for a walk and have a good think then lots of :coffee:
Post by: PekkaNF on October 09, 2018, 12:46:57 PM
Very good. S5-135 CPU was breifly pretty familiar to me. We had to use because it had some math functions for I/O that cheper models were lacking. If I remember right, there were few versions of it. Ladder and all that is all standard, fun starts with time-base functions and math, it was very feasible to have some programs on short time base and then push some longer loop.
Pekka
Post by: awemawson on October 09, 2018, 12:55:50 PM
Post by: PekkaNF on October 09, 2018, 03:16:17 PM
Post by: awemawson on October 09, 2018, 03:31:23 PM
Post by: PekkaNF on October 09, 2018, 05:19:38 PM
Pekka
Post by: PK on October 10, 2018, 01:16:32 AM
Post by: tom osselton on October 10, 2018, 02:24:18 PM
I hope you're not using that Single Malt for weld preparation :lol:I just thought it was medicinal for the welders flash! :lol:
Post by: awemawson on October 11, 2018, 09:05:30 AM
So now back in and working I've been doing a bit more investigation of what I can see in the PLC via STEP5. The PLC program comprises 'blocks' of instructions, arranged as 'organisational blocks', 'program blocks', 'function blocks', 'sequence blocks', and 'data blocks'. One of the myriad of STEP5 facilities is to download these various block either by their reference numbers, or all together as one file. Trying the latter approach (as I don't yet know the reference numbers' seems to start off OK, loads of data being transferred, then everything locks up, STEP5 freezes, Program Manager shows it's using 100% of the CPU time, and the only way to stop it is to use Program Manager. When PM stops the program the entire operating system crashes - yes this is repeatable :bang:
So what blocks do I know should be there - apparently all the PLCs have OB 1, which is the interface between the operating system in the 820T controller and the user program. So I set it up to down load OP 1 - and it did it ! But I can't find how to read the file I've downloaded !
OK what else can I do - well there are various internal things in the PLC that can be brought up on the screen - not yet familliar enough to know what it all means but I suppose it's a bit more progress - have a few screen shots !
Post by: russ57 on October 11, 2018, 09:20:29 AM
Russ
Post by: awemawson on October 11, 2018, 11:01:40 AM
I have the .pdf version of a manual for STEP5 V7.0 but mine is V7.23 - probably much the same apart from details. I've given up scrolling up and down screens cross referencing stuff in the manual, and knuckled down and printed it out this afternoon. Only 513 pages or an entire ream of A4 paper !
I find it much easier with a paper manual that I can stick Post-It notes on to temporarily mark my passage through the jungle.
One issue is that all the documents I've found so far start off getting you to construct the logic of a program, program it and upload it, but include very little about the reverse process starting from an existing but undocumented program already in a PLC !
But applying PK's poster regarding persistence (which I've printed out!), we'll get there eventually or I'll !now the reason why not!
Post by: PekkaNF on October 11, 2018, 12:18:34 PM
.....
One issue is that all the documents I've found so far start off getting you to construct the logic of a program, program it and upload it, but include very little about the reverse process starting from an existing but undocumented program already in a PLC !
....
Because trying to make sense of BU is very hard.
99.99% professionals have source code and then try fiqure out what has been changed in the code on PLC and when circuit has been found zoom in to FB/PB "What it does and why"?
To get there you use compare -function and cross reference of I/O, but hard to do if you don't have commented source code.
If I had to do it I would find the outputs that drive the tool cahnger (if that had a problem). Cross reference the outputs one at the time, then find the blocks that drive those outputs and then check which inputs make up the logic.
Trying to understand the whole big tamale is a big project.
Pekka
Post by: awemawson on October 11, 2018, 03:29:51 PM
A bit more poking about confirms that I have managed to download three 'blocks' from the PLC and can examine them and potentially edit my local copy. I don't think I can modify the code in the 820T PLC yet as A/ some is in EPROM and B/ the rest (all 18K of it) is at this point sacrosanct until I undersatand it better.
OK what have I got? Well I have 'OB 2' - (organization block #2) which is quite short having only a few lines and is apparently the interrupt service routine for high priority interrupts, but VERY interestingly refers to the 'W-Axis' in plain text, conditionally calling up 'FB 99' to service this interrupt. And FB 99 also refers in plain text to the W-Axis.
Why all the excitement about the W-Axis when this lathe hasn't got that option? Well it's not the axis that gets me excited, but that fact that some of the code obviously includes plain text giving a clue as to its function, which will help enormously.
As an aside I'm sure that I've read in one of the commissioning guides for the 'GEN2' lathes (mine is 'GEN1') that the commissioning Engineer was instructed to run a program that examined the options required by the particular customer, and create the PLC program by assembling blocks, so I assume that blocks are enabled or disabled in fact from the W-Axis one I've found.
Having now printed the documentation I've decided to 'start over' with the set up of the file structure on STEP5 to isolate my 'project' from the various examples etc, and thus get a clearer idea of what is stored where.
Post by: PekkaNF on October 12, 2018, 04:18:24 AM
OB 1 "Cyclic" calls PB:s (ladder)
OB 2 is intterrupts, you don't want to saturate this file with may simultaneous calls
OB 10-18 calls programs on certain time base, we used them on FB:st that had exacting time requiremets like counters, positioners, servos etc.
OB31 "cyle time monitor" is a lot of fun if your CPU gets loaded! It is really easy to exceed cycle time if you have too much junk on too fast loop.
You know these OB calls? p. 97
https://cache.industry.siemens.com/dl/files/150/1086150/att_1992/v1/948then.pdf
And one thing to know that there are two flags set and used routinely trought the program to enable/disable piece of code "permanently":
"FALSE" in case of M0.0
"TRUE" in case of M0.1
Just in case you wonder what these are.
pekka
Post by: awemawson on October 12, 2018, 06:15:08 AM
I have a rather bad photocopy scan in pdf format of a Siemens guide to programming this particular PLC - I'm trying in vain to find a better copy that is in 'pdf searchable' format rather than just images. It's this document if you happen to have a source:
6Zb5-410-0BX02-0BA0 (or 0BA1)
Post by: awemawson on October 13, 2018, 05:36:32 AM
820T end no issues, parameters 5011 & 5013 set to 11000110 equating to 4800 baud, all else unchanged.
At the PC end however something very odd is happening. I set up the COM2: using MODE in a dos box, then hop into STEP5, which refuses to go 'on line'. Back to the DOS box only to find that COM2: has reverted to 9600 but at 7 data 1 stop. Device manager shows the correct setting. Now as I understand it there can really only be three things changing the port settings:
1/ Me using the MODE command
2/ Device Manager
3/ STEP5 perhaps using a configuration file that I've not yet discovered
But the really odd thing is, if I revert back to 9600, No Parity, 8 data 2 stop everything works, STEP5 goes on line to the 820T controller and when I come out of STEP5 the com port is still as I set it.
Not managed to resolve that conundrum yet :scratch:
So per force continuing at 9600 I discovered that I can display a directory of all the blocks in the PLC. If I try to download PB202, which is the first, and biggest block, (and the only program block in fact), the interface locks up as it did when I told it to download 'all blocks'. If I tell it to down load the next listed block FB11 I get I get an error 'last segment not completed', but every other block I have managed to download to the local file and can open them for display and editing. However there is not much meat in them, I think the action is mainly happening in the elusive PB202.
Now when the interface locks up, I can only stop STEP5 running by using Task Manager to terminate it, and doing so brings down the whole operating system requiring a re-boot of Windows XP-Professional. However looking at Task Manger I notice that there is a service "IASTORDATAMGRSVC.EXE" that seems to be using 100% of CPU time.
Googling about I find that this service is not part of Windows but is part of "Intel(R) Rapid Storage Technology" and apparently isn't needed, but if I try to uninstall it using 'Programs and Features' in Control Panel I get my hand slapped telling me that it's controlling my hard disk and if I do I'll loose data and won't be able to re-boot :bang:
. . . oh what fun . . . .
Post by: russ57 on October 13, 2018, 06:13:17 AM
Did you work out how to control the download location?
If so. Try either writing to a separate disk (usb?) or even, assuming it's still possible, a ram disk.
Is @@ valid? I think it wasn't in some file systems.
Russ
Post by: awemawson on October 13, 2018, 06:42:01 AM
The @ signs are inserted by STEP5 to pad out to the 8.3 dos name convention, and it's writing ok to the same file for the other blocks from the PLC. This leads me to think that either the PLC program in the PLC is corrupt in some way, or that the the RS232 data link is giving problems. The PB202 block is the longest one - maybe the software hand shaking isn't working properly. This doesn't explain the FB11 'last segment not completed' error, which is quite repeatable, as FB11 is shorter than most of the blocks that I have transferred successfully.
In an ideal world I'd like to slow the interface down such that handshaking is no longer needed (ie both ends can easily cope with the slow data rate without needing to pause for breath), then crank the rate up until failure, but something at the PC end is stopping me being in control of the Com2: settings
Post by: russ57 on October 13, 2018, 07:02:51 AM
It could be a corrupt block on the controller as you suggest.
That would mean step 5 hangs waiting for more data that never comes.
Re com settings, I agree with your analyis that step 5 is setting it. I'd search the entire installation for 9600 and see if it is a config somewhere.
Russ
Post by: awemawson on October 13, 2018, 07:52:43 AM
I'm planning another session this afternoon - obviously the last bit of the transfer will be the interesting bit when it has just locked up, but by heck things don't half get confusing :bugeye:
Post by: russ57 on October 13, 2018, 08:00:44 AM
Throw in Bluetooth, packet encryption, Android and 4g network none of which take kindly to a request to explain what is going on.
Russ
Post by: mc on October 13, 2018, 08:09:48 AM
The newer genuine Saleae analysers are analogue, and a lot more expensive, but these basic digital only ones are handy for this kind of thing, and work with the Saleae software (the original Saleae interfaces were identical electronics to these cheap ones, but in a fancy case). Only limitation to storing the captured data is disc space, and the software includes various analysers/decoders - https://www.saleae.com/
Post by: awemawson on October 13, 2018, 09:52:22 AM
Having just now hooked up the Tektronix 834 RS232 analyser I've realised that it is actually reporting 'Framing Errors' on quite a few (but not all) characters in both directions ie from both the STEP5 PC (DCE) and the 820T (DTE).
Now this may well be a red herring, as of course we have also got the set up on the 834 analyser as well as both ends of the link which have to match. Theoretically they all do match !
. . . but I've been driven out of the workshop again by a plague of flies :bugeye: - this time far fewer than before and hopefully just the 'tail end charlies' of the last batch but I can't concentrate when they literally drop down the back of my neck into my shirt !
Post by: mc on October 13, 2018, 10:48:57 AM
If you did rig up a basic level shifter, it would mean you could see exactly what's going on with the signal timing, which may reveal what's causing problems.
PS. A beekeeping suit would solve your immediate fly problem, and keep us entertained!
Post by: awemawson on October 13, 2018, 11:02:44 AM
I PS. A beekeeping suit would solve your immediate fly problem, and keep us entertained!
Bee .... off :clap:
Post by: PekkaNF on October 14, 2018, 03:20:29 AM
Another thing is that all the old Siemens programs configured the port in the S5 application program, if you didn't have the serial port on COM3 (from my memory) - tough luck and you have to do some fuckery in the BIOS. I did not touch that, I let others who thougt they knew.
Then again Sinumerik might be different on that one too.
Pekka
Post by: awemawson on October 14, 2018, 05:28:47 AM
The cable I've been using in the main is the one that I can happily load the 820T from and also dump back ups - usual screened RS232 stuff.
Guests for lunch today so not much will happen, but I've ordered one of those gizmo's that Moray linked to, along with a MAX3232 board to convert RS232 / TTL. It looks a generally useful bit of kit at a very low price. It hopefully will let me more easily see character length to find this framing error thingy. Trying on a conventional 'scope is a pain as the triggering is inconsistent (as is the data I'm looking at).
This version of STEP5 has a drop down box to select which COM port to use - lucky as I only have COM2: available, but the silly thing is that the bit where the com port is selected doesn't have anything to select the ports parameters.
One has to remember this program was written in an age when expectations were far less, and things have moved on considerably since then in terms of usability.
Post by: awemawson on October 17, 2018, 07:31:09 AM
OK Moray kindly pointed me at a cheap 'logic analyser' that would let me capture signals between the STEP5 program on the Toughbook, and the Siemens 820T controller. But these signals are at RS232 levels and the analyser is expecting TTL levels.
No big issue - either make or buy a converter based on the MAX3232 chip that does precisely this conversion. So, the USB analyser, a MAX3232 board, and some 9 pin IDC plugs and sockets ordered, all of which came to hand yesterday.
The MAX3232 board needs a 5 volt supply, so I modified a USB cable to give me this, and made up a short Male, Male, Female adaptor cable for the 9 pin Toughbook serial port to allow connection to the converter card as well as onwards to the 820T controller.
First I set it all up just transmitting from the PC using the "COPY CON COM2:" command in a DOS box, and sure enough up it came on the analyser.
Then I tried connecting the serial port onwards to the controller, but no way would it go 'on line' Much chasing about then it dawned on me, the little MAX3232 pcb has one "RS232 to TTL" and one "TTL to RS232" port connected (the MAX3232 has two of each) - what I wanted, as I was just monitoring the interface, was a pair of "RS232 to TTL" converters. What was happening was that the RS232 output of the PCB was in parallel with the RS232 output of the 820T controller and clobbering it :bang:
Oh well, best laid plans of men and mice . . . . etc !
Frustratingly the PCB was laid out such that there was no realistic way of using the other port on the MAX3232, but I have found another version, a "Sparkfun BOB-11189" that doesn't embody a 9 pin Sub D, but does bring out all the inputs and outputs to accessible places - one on order from Farnell.
But what I HAVE manged to confirm, is that the STEP5 PLC monitoring software is definitely altering the COM2: port settings to 'Even Parity' each time it is run, and thus generating the 'framing errors' as the controller expects 1 start bit, 8 bit data, no parity bit, 2 stop bits ie and 11 bit word, but it is getting a 12 bit word with even parity !!!! No idea how or where, and still seeking enlightenment :coffee:
. . .so that's the current 'state of play'
Post by: awemawson on October 17, 2018, 01:30:11 PM
Sure enough it had EVEN for the parity bit for COM2: that I am using. I edited it to 'NONE', ran the program, and it STILL sets it up as EVEN parity :bang:
. . . my head hurts !
Post by: russ57 on October 18, 2018, 04:00:13 AM
If only they would exit stage left and leave the main characters to read the script...
I would think, as a last resort, you could set an arduino or similar to act as a protocol converter.
Last thought
Can you reinstall using the new ini file? It may just use it to set some run config when it is first installed /configured
Russ
Post by: awemawson on October 18, 2018, 04:14:45 AM
I've set the COM2: to what I believe I need using MODE, run STEP5 then (exiting STEP5 first as otherwise it still has hold of the COM port) then typing just MODE COM2: to see what it's set to find that STEP5 has modified it yet again :bang:
Yesterday I thought, OK, that's what STEP5 seems to want, so (contrary to the instructions) set the Siemens 820T controller to those settings and see what happens. It will still go on line but locks up as before.
All very intriguing, rather headache provoking, but never the less interesting. I wish I could have a few hours solidly 'at it' but things keep getting in the way !
I just hope that PK is having more success and less headaches down under - not heard from him in a while. :scratch:
Post by: russ57 on October 18, 2018, 06:59:19 AM
Russ
Post by: awemawson on October 18, 2018, 07:23:24 AM
STEP5 was originally written I believe for CP/M where you had far better direct access to hardware than Windows lets you have.
This of course is a distraction from a detour from a diversion on the way to trying to solve the 'Spindle Orientation' issue, and although I'd love to be able to poke around in and maybe re-program the PLC it wasn't an objective that I chose!
I'm getting closer to being driven to load the PLC program from the other (smaller lathe) and see if the spindle orientation works with that. But it would have to be done with the greatest care in case the axis etc are over driven. :bugeye:
Post by: awemawson on October 18, 2018, 10:19:24 AM
No time at the moment to go into it much deeper, but here is my first screen shot showing the transmission from the STEP5 port and the response from the 820T controller - need a bit of quiet time to dig into it further.
Post by: awemawson on October 19, 2018, 05:49:40 AM
To my great surprise the block down loaded error free !
OK on a roll I decided to download the one other block (PB202) that previously had locked everything up and caused STEP5 to crash the operating system - sure enough it whistled through error free - very very odd. I've left the interface settings as STEP5 has modified them on the PC, but the 820T controller is still set up 'as was'
So PC set to 9600/Even Parity/8 data/2STOP/XON=off/CTS=off/DSR=off/DTR=on/RTS=on
820T set to 9600/No Parity/8 Data/2 Stop/XON=on/CTS=off/DSR=off/DTR=off/RTS=off
No idea why this is now working - but it is!
But the very odd thing is that when I look at the various 'Program Blocks' and 'Function Blocks' there is just not enough 'meat' in them to be the complete PLC program - the only block with any substance is the one that seems to control the 'W-Axis' which is not even used on this lathe.
So something is missing somewhere - there must be a back door into this PLC thingummybob that I've not found.
Post by: WeldingRod on October 19, 2018, 09:29:35 AM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on October 19, 2018, 09:44:06 AM
First the Directory - (it was one line longer than a screen so I cut and pasted it !)
Then OB 1 which is the entry point for the program
Then OB 2 which is called on interrupts (and only seems to call the FB 99 W Axis routine)
Then PB 202 which should be the main program block
Then a couple of function blocks (FB11 & FB 60 as examples of 'no meat'
Then FB 99 the W axis service function that isn't used but is meaty !!!
There just HAS to be more to the program than this trivial bit :scratch:
Post by: mc on October 19, 2018, 11:03:51 AM
The thing that stands out to me, is what's the significance of the Segment 1 on all the screens?
Is there some way to access more segments?
Post by: awemawson on October 19, 2018, 11:30:00 AM
Looking at the guide to programming the PLC most, but not all, of the FB function blocks listed in the PLC directory are standard ones that do things like transferring data to and from the PLC and NC parts of the controller.
It all looks pretty shell like and empty if I'm honest, and it's really odd that the one FB that looks OK to my untutored eye, is FB_99 for the non-existent W-Axis.
I'm trying to formulate a concise but meaningful question for the Siemens forum about this - they are an odd lot, and the moderators tend to kick things into touch if you are not careful how things are phrased and ramble too much! It's a question of getting all the graphical information into the single picture that they allow !
When the controller is loaded from an empty state you start loading NC Data and PLC Program and data, but then there is an 'ASM' file that no-one can explain what it is, but I strongly suspect that it is compiled assembler code - the only reference to it I've found calls it a 'dump of user memory'.
I'm tempted to do a reload without the ASM file, and try and go on line to the PLC and see what's in it. If the ASM file IS compiled assembler code for the PLC then surely the PLC program has to hook into it to use it at various points, and I see no sign in the 'Blocks' I've downloaded.
It's no tiddler at 207Kbyte and takes 30 mins to load !
Post by: russ57 on October 20, 2018, 02:18:14 AM
Russ
Post by: awemawson on October 20, 2018, 04:05:09 AM
The original file that it seems to be writing to was named "820T@@ST.S5D" - (I say seems to be writing to, my only real clue is the date and time stamps on the files).
I've downloaded it to my desktop PC (remember that STEP5 is running on a Toughbook CF-52 under Win XP) and had a look using 'Hex Editor Neo' which lets me display in plain ascii text, hexadecimal or binary. Sure there are areas where a bit of recognisable text appears but the overall structure is still not clear (to me at least)
I've renamed it as a 'TXT' file so that I can attach it to this post - maybe others will have more success than I :scratch:
Post by: awemawson on October 20, 2018, 04:46:05 PM
Sometimes things are far simpler than you think, I've just been given a tip by a chap on the Siemens Forum that to see the other segments PRESS THE PAGE DOWN BUTTON :clap: :clap: :clap:
. . . . :doh: :doh:
If I get time tomorrow I'll experiment and see what I can see and post progress, for now I've just popped out to the workshop to prove the theory and it works - lots of segments.
Post by: tom osselton on October 20, 2018, 07:16:42 PM
Post by: russ57 on October 20, 2018, 10:41:56 PM
Russ
Post by: russ57 on October 20, 2018, 10:42:28 PM
Russ
Post by: awemawson on October 21, 2018, 04:55:21 AM
Below is a random but not untypical segment, segment 92 displayed in 'Ladder Format'.
Todays job is to try and find how I can get the graphical representation of the whole 172 segments into a readable file or out to a printer. Taking screen shots, or as I've been doing this morning actually photographing screen images isn't really practical to get to grips with this beast.
STEP5, being from the era that it is is expecting a printer on a LPT port - well it's out of luck, because even if I had a suitable parallel connected printer the Toughbook hasn't got an LPT port.
It's running under XP professional, but won't use XP's default printer (an HP Laser on my network) although XP is happy with it.
More questions to the Siemens forum coming up I think!
Post by: awemawson on October 21, 2018, 10:50:51 AM
It's all very clunky, and all data for printing has to be put into an '.INI' file and an off line utility run - most peculiar !
But although I can cheerfully print directory listings of the program elements (Program Blocks, Organisation Blocks etc) at the moment I cannot find how to print the contents of the blocks themselves despite being able to see them on the screen. It surely MUST be possible, it's just I'm being dense I suspect :scratch:
I can even print out cross reference tables of all the inputs and outputs to the PLC program, but not the actual code or ladder logic - very odd, but this whole PLC escapade has been very odd so why should it change now :lol:
Post by: awemawson on October 21, 2018, 01:05:31 PM
Meanwhile, looking through the code for the W-Axis (which isn't fitted to my lathe) I can successfully map the output "Q bits" in the PLC code to the input bits on the circuit diagram that I have. This is encouraging - if eventually I can do the same for the M20 preparation code for Spindle Orientation that started this particular investigation what seems months ago, then I'll be a very happy bunny :ddb:
Post by: AdeV on October 21, 2018, 03:57:09 PM
Post by: awemawson on October 21, 2018, 04:25:08 PM
No, a long way from G code !
PLC's or Programmable Logic Controllers evolved to eliminate the masses of relays found in many automation systems as they were a constant source of failure, were expensive to build and fault find.
Consider the PLC like an electronic ULA or uncommitted Logic Array, that has loads of inputs, loads of outputs, and is programmed to define the logical connections between inputs and outputs.
The PLC goes one further step and can incorporate timers, latches, and interrupt service routines.
Now there are several ways this logic can be portrayed. In my view the simplest is the 'ladder logic' with decisions shown as open or closed switches. You have such a ladder of contacts in your Bridgeport Interact for the 'eStop Chain' where the ultimate end point is to open the eStop relay if things aren't safe.
'Ladder' because the original relay logic contacts were strings between the positive and negative rails of the supply each string making effectively one decision, and when drawn out looking like a ladder!
Below is a slightly more complex bit of my PLC ladder (Segment 92) where an RS Flip flop is involved :
Flag bit 47.2 sets the RS flip flop if Flag bit 142.2 is True
Flag bit 47.1 clears the RS flip flop if Flag bit 142.2 is True
And the resulting output of the flip flop is presented to the interface as output bit Q0.2 which on my lathe is an actual hardware output 'Chuck Low Pressure Select'
(it equally could have been another flag bit to be used as input on another rung of the ladder)
I've no doubt that ultimately Flag Bits 47.2 and 47.1 will be derived from decoding M codes (or machine control codes) in the running program but I've not got there yet !
. . . niffty eh :ddb:
Post by: Pete. on October 21, 2018, 05:38:06 PM
That wouldn't be giving me any more trouble by now if I was working on it :hammer: :hammer: :hammer: :hammer:
Post by: AdeV on October 22, 2018, 02:29:57 AM
Although one immediately wonders what would happen if bits 47.1 and 47.2 were both set to true! (a real RS flipflop would output 0...)
I can see why you want a printout of the whole thing, it must be a bear trying to trace it all one logic unit at a time... It will be interesting to see if the Mazak has something similar (I guess it will).
Post by: David Jupp on October 22, 2018, 03:38:22 AM
Post by: awemawson on October 22, 2018, 03:49:11 AM
Chap hasn't got back to me yet BUT I'VE DONE IT MYSELF :ddb: :ddb:
Simple when you know how and ignore the distractions in the manual that refer to printing and seem to have no relevance what so ever !
.PDF attached of the whole of PB202
Post by: AdeV on October 22, 2018, 04:16:41 AM
What are the segments that look a little like machine code? And what do they do? :scratch:
I reckon, if you gave me a week & a text version of that file, and a few hints from the manual, I could come up with a nice lathe simulator for you :lol:
Post by: awemawson on October 22, 2018, 04:23:44 AM
Next step is to cross reference the ladder programs inputs and outputs to the corresponding entries on the various other documents such as the circuit diagram and wiring lists. That should hopefully start to reveal where the M codes are handled. I think that there is a documentation feature in STEP5 that will allow me to put 'labels' on the local copy of the PLC program which will make things far easier to understand.
. . . but I must confess to a warm glow this morning having got this far :palm:
Post by: awemawson on October 22, 2018, 04:27:27 AM
Crumbs - I'd not like to try to work that lot out without a manual and a stiff cup of coffee!
What are the segments that look a little like machine code? And what do they do? :scratch:
I reckon, if you gave me a week & a text version of that file, and a few hints from the manual, I could come up with a nice lathe simulator for you :lol:
I believe those sections are STEP5 commands that must be doing clever things yet to be revealed - I do have the list of commands if you fancy a bit of homework :lol:
Something must also hook into the vast ASM file that gets loaded but all this excitement is still over the horizon :clap:
Post by: mc on October 22, 2018, 05:45:48 AM
It's only 33 pages, and the first doesn't even contain any segments... :D
Post by: awemawson on October 22, 2018, 06:58:17 AM
I have, though, started the cross referencing - just a few labels at first to see how and where they appear. When inserted they are displayed on the screen in a tasteful yellow when you click on an input or output, but not in printed versions. I'm sure that it must be possible to get them on the print out, but I've yet to find how other than editing the .PDF (which I don't want to do as within STEP5 the label pop up in all sorts of different screens).
. . . so much to learn . . .so much fun . . .so many Aspirins :lol:
Post by: PekkaNF on October 22, 2018, 09:02:51 AM
If I remember right in S5 lingo S-R has reser overriding and R-S has set overriding. Modicon and Telemeganique had it it opposite - or A-B! Anyway, I had to check every time I changed my "language".
S5 has interesting timers, to convert S5 to Modicon had to make some extra logic to accommondate some of the timers used in S5, but not suported in Modicon.
First you need to check the offending outputs on harware, crossreference where outputs are set (only once in the program or someone has ****** up) and there you find the segmet it is set. Backtrack from there.
Commenting few segments and most inputs/outputs is a half a battle, figuring out the flags (typically exceptions like E-stop, Low hydraulic pressure, alarms, permits or states like "run" or "pause" or "jog" takes a little more tennacity.
But you are the man!
Post by: awemawson on October 22, 2018, 09:24:55 AM
I can display the PLC program as CSF, LAD or STL
CSF - Control System Flowchart
LAD - Ladder
STL - Statement List
But I suppose not all constructions are possible to display in some formats hence interspersed statement lists. Here is an example of SEG-2 in all three formats
Incidentally that I4.4 is eSTOP, I7.7 is 24 volts OK, Q 7.0 is a spare output, but I have as yet no idea what F 24.3 is except that it's an internal flag bit, or what Q78.1 is, again it's an internally used output from the range it sits in.
Perhaps I should explain I's are inputs F's are flags (temporary one bit memory) and Q's are outputs. So Q 1.2 is output word 1 bit 2 for instance which would be 'select low gear on this lathe.
( all this is me trying to familiarise myself with what I'm working with - sorry if I'm boring you all :scratch: )
Post by: awemawson on October 22, 2018, 09:54:13 AM
Segment 1
:STL
:L KH 0202 Load Hexadecimal 0202 into Accumulator 1-L
:T FW 121 Transfer contents of Accumulator 1-L into Flag Word 121 bits 8-15 to byte n, bits 0-7 to byte n+1
:L KH 0020 Load Hexadecimal 0020 into Accumulator 1-L
:T FW 119 Transfer contents of Accumulator 1-L into Flag Word 119 bits 8-15 to byte n, bits 0-7 to byte n+1
:***
Which can only be represented as a statement list, as flowchart or ladder are not appropriate
Post by: tom osselton on October 22, 2018, 04:22:11 PM
I’m waiting for the lightbulbs to turn on!
Post by: awemawson on October 22, 2018, 04:40:01 PM
I've just spent the evening gleaning all the 'I bits' (ie inputs) from the circuit diagrams that I have and typing them into a cross reference file that STEP5 uses to translate absolute labels (such as I 8.1) into symbols.
Next task is to do the same for all the outputs (Q bits) from the circuit diagrams, then try and pick up the internal 'standard' flag words from the 'Guide to writing PLC programs from Siemens.
Hopefully when those tasks are completed the 33 pages of program will be more user friendly bed time reading :lol:
. . . of course all this effort is no guarantee that the 'M20' issue that I'm seeking will be revealed, or indeed that the issue is even IN the PLC :bugeye:
Post by: AdeV on October 22, 2018, 05:55:07 PM
bits 8-15 to byte n, bits 0-7 to byte n+1
Ugh, I hate little-endian systems with a passion, they just don't feel right.
BTW, you might already have this manual, I can't remember off-hand, but in case it's useful, it appears to contain a Step5 programming manual: https://cache.industry.siemens.com/dl/files/940/1085940/att_1156/v1/pa928ben.pdf
Post by: awemawson on October 22, 2018, 06:10:07 PM
Assuming here, but I suppose that Siemens decided rather than have a physically separate PLC they could time slice the CPU in the controller to do the same job logically. The PLC even reports itself as a 135 when I connect to it.
I've yet to get fully to grips with it, but as I understand it the PLC copies it's field of input and output data to the CNC controller and vice versa once every pass of the program and that is how they communicate, setting the flag bits.
. . . It's a whole new world in there ! Bring back COBOL or ALGOL I say or even FORTRAN but I was happy with Z80 assembler :clap:
Post by: PK on October 24, 2018, 04:21:17 AM
And we're in!..
We can now trace signal from the transmitter through to the receiver and make sure it's waking up...
We've flashed some IR at the transmitter and seen signal come out of it's photodiode, so it looks like that bits OK now....
Post by: RotarySMP on October 24, 2018, 07:22:18 AM
Thanks for posting in this manor, as your documentation of your systematic approach to trouble shooting is a good lesson in how to solve this kind of problem.
Is there a point where you cut your losses, dump the original controller/PLC and retrofit to LinuxCNC? I'd appreciate hearing your thoughts on that.
On my MAHO 400E I didn't go very far down the path of fixing the existing Phillip's 432 installation, as the functionality of a 2.5D controller with 16kb ram didn't seem worth it, when compared to the significant improvement in capablity with LinuxCNC (full 3D, unlimited program length and look ahead). On a lathe I guess that equation balances out differently.
Mark
Post by: awemawson on October 24, 2018, 07:28:44 AM
But I'm a little confused - are you saying that the OMM is now responding both ways, or the probe module ?
Post by: awemawson on October 24, 2018, 07:32:41 AM
99.9% of the PLC is working fine and is rather good, so absolutely no way it'll be changed.
I've spent a couple of days pouring over all the documentation that I have, and suitably cross referencing the innards of the PLC program - I'm up to just short of 300 references in the list so far :bugeye:
However I am closing in on the M20 issue, having identified the bits of the program that are activated by M20 - it's an uphill struggle but progress IS being made.
Post by: RotarySMP on October 24, 2018, 08:07:00 AM
Mark
Post by: awemawson on October 24, 2018, 08:44:02 AM
Prior to that I had semi-done a Bridgeport / Moog (*) Hydropoint-1000 NC machine - it had hydraulic servo positioning, and pneumatic instruction reading by blowing air though punched paper tape 24 bytes at a time. I made a 'behind the tape reader' interface for it reading and writing driven serially off a PC parallel port using compressed air and tiny valves !! (and it worked!)
(* The MOOG in question was the brother of the Moog Synthesiser one which is where he got his pneumatic read concept. He went on to make hydraulic control valves for NASA for the 'man on the moon' program. In fact there is one of his hydraulic proportional control valves in the control loop of my Eurospark H425 die sinker EDM machine)
Post by: awemawson on October 24, 2018, 11:45:05 AM
Sadly the way the STEP5 'Documentation' function works, it lists the named items under the particular segment, rather than substituting the names in the actual segment of the ladder, but hey-ho it's better than nothing.
I think I've identified everything that is in the bits of documentation that I have, so from now on it's going to be a case of trying to work out the function of items then naming them myself.
An example is in Segment 61 where there is an S / R latch that is SET by the dynamic M code M20 (that is giving me the issues) Now I KNOW that Flag bit 31.4 is set for an M20 from documentation that I have, so it's been given an appropriate name. But the actual R/S latch, being implemented by Beaver when they built the machine, is NOT in any of the Siemens documents, but it still needs naming to understand the rest of the ladders, so I've christened it M20ACTV (or M20 active the label is limited to 8 characters) - so references to F 149.4 (bit 4 in flag byte 149) will later in the ladder have a name that MIGHT prompt more understanding !!
. . . lots more to do though
Post by: awemawson on October 26, 2018, 05:35:41 AM
However four hours of thinking time on the journey got me to a diagnostic method that I applied this morning. Now that I have the entire PLC program on paper, and can inspect inputs, outputs and flags using the inbuilt facility in real time I can trace what is happening.
So the problem is, that issuing an M20 ('Enable Spindle Drive') command that is the preparation for M19 'Spindle Orientation' the M20 is entered but then locks the control by not asserting the 'Read In Enable' line, so the control is freezing and not reading the next command. However the bits are set in the flag words that the spindle is indeed enabled by the M20.
Now having the PLC ladder in front of me like a circuit diagram, I can go through the logic that asserts 'Read In Enable', which is segment 77 that is a simple dependency on both F 136.6 and F 138.5 being False (or 0). This showed me that F 138.5 was the problem being at a '1'
The previous 'Segment 76' produces the flag bit F 138.5 from a twelve input structure requiring all it's inputs to be '0' (apart from one where the logic is inverted for 'Turret Card Fault') and the failing input was traced to the third input element being F 149.4 (M20 Active) in series with I 5.1 (Spindle Clamp Pressure Switch)
Well guess what - although the spindle clamps OK with an M31 and unclamps OK with an M32 the input on I 5.1 is the inverse of what I would have expected, with a '1' for unclamped and a '0' for clamped.
How could this possibly happen :scratch: Well think back to the end of July, when I got all enthusiastic replacing the solenoid and pressure switch sockets as the old ones had perished - I couldn't possibly have wired it wrongly could I - oh yes I could :palm:
So a quick wire move from the NC to the NO terminal, and guess what - the M20 command now completes as it should and the following M19 command is read in :ddb:
However I'm not out of the woods yet, as the M19 keeps the 'Run' light on and doesn't orientate the spindle but just sits there glowing :bang:
OK never mind, this IS actually major progress as now I can hopefully trace out what is happening just as you might with the equivalent physical relay circuit and a multi-meter.
Not every item in the PLC ladder is yet named, and probably never will be, but this method will let me concentrate on the area with the issue rather than having a scatter gun approach
Post by: russ57 on October 26, 2018, 06:25:43 AM
I reckon that is indeed significant progress.
-beating step 5 into grudging cooperation if not actual submission
- a window into the logic, if not a door.
-substantial progress in your spindle issue
-fixed one of hopefully only two defects (even if it was one you introduced
) Russ
Post by: awemawson on October 28, 2018, 03:04:28 PM
Today I found out that one of the pressure switches that monitors chuck clamping was permanently 'made' - entirely by following the ladder logic, but the frustrating thing is that either they have been wired wrongly, or the circuit diagram is wrong. They are pretty well impossible to get at and determine which is which - certainly can't at the moment as still in Sunday Best :palm: - a job for tomorrow slackening a hydraulic fitting and see if clamp or unclamp covers me in oil !
Hopefully I can pull it out and re-work it as I very much doubt that they are a shelf item any more - have a picture.
I'm also attaching the latest .pdf version of the annotated PLC program for those of you that can't get to sleep at night :lol:
Post by: WeldingRod on October 28, 2018, 05:05:06 PM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on October 31, 2018, 08:21:31 AM
https://madmodder.net/index.php/topic,8741.msg152687.html#msg152687
Post by: awemawson on November 01, 2018, 08:09:31 AM
In desperation I have typed into the 'Machine Data' for the controller the values of parameters for Spindle Data from the TC-10 back up that I obtained, where they differ from mine. And guess what, the servo loop IS closed, and the spindle rotates to approximately the programmed position but then oscillates around that position never completing the command. Parameters changed are:
#4010 Drift Compensation (Spindle) was 2 now 6
#4270 Cut Off Speed M19 Gear 1 was 5 now 10
#4350 Gain for M19 Gear 1 was 2000 now 7000
#4430 Positional Limit for M19 was 2 now 1
#4500 Set Reciprocation Speed was 100 now 0
So I conclude that the spindle positioning servo loop parameters need tuning. I have tweaked all these values up and down a bit but not yet found any one that stops the hunting.
Bear in mind that the other lathe is different. It only has one gear whereas mine has two, so parameter #4350 for instance where the servo gain is very different (7000 as opposed to 2000), in fact mine was originally 7000 for Gear 2. Also my main spindle motor is significantly bigger than the TC-10 one.
Need to research servo tuning, but what amazes me is that with my original values there was no apparent servo action on the spindle at all - very odd.
But this IS another major step forwards :clap:
Post by: seadog on November 01, 2018, 11:28:08 AM
Perhaps the drift compensation is damping. (Then again, perhaps it isn't)
Well done!
Post by: WeldingRod on November 01, 2018, 03:54:22 PM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: cnc-it on November 02, 2018, 12:16:33 AM
Post by: PekkaNF on November 02, 2018, 03:26:54 AM
Also on the Mentor drive there are pots for tuning..I used them for setting the rpm after I had my motor re built..worth a try?
So does that drive has cascade contoller:
1) Inner loop for curren or torque i.e. motor "native" possibly analog control loop
2) Outer loop in PLC for position control
Cascade controller are pretty sensitive that way. When I had to tune somewhat similar system, we did it shis way:
1) Make sure that inner loop HW stop works with limitswitces or such (would be drag to crash it)
2) Remove PLC control loop totally from inner loop, we used programmed step respose generator for inner loop SP.
3) Use step response to tune inner loop as tight as possile, but make sure that it has enough stability to live with wear, changing load etc.
4) After inner loop step response is good , connect inner loop to outer loop and adjust outer loop.
Gain ratio is critical, inner loop should be least 10x faster or controllers start fighting. If cascaded controller outer loop is too tight to inner controller it will cause bad behavour.
Now, if the outer loop gain has to be too high for confort (it will try to ocilate in certain ocasions) there are few paramaters to play with like dead band (When position is "good enough" and correction would send the controller to hunt near SP) and derivate type parameter (how small error you want the controller to react).
We also used "Forward" controller type: Depending the difference on measured value and setpoint, the controller would lock the outer loop AND shoot the inner loop with precalculated (massive) step to jerk the system "close" and when "nearly there" would release the outer loop controller that would do it's job gently to control exact position. This needes the system to be modelled or tables of mass and transfer distance - like you change the moving mass and then your step response to moving distace had to be different.
Hope I did not confuse anything further. We did not made machine tools, but machines that sometimes had a lot in common with machine tools. I.E. linear rails, torque/speed/position control loops with electro hydraulics or electrical servos.
Pekka
Post by: awemawson on November 02, 2018, 04:02:37 AM
The control loop seems to be pretty well confined to the inner workings of the Siemens 6FX1121-4BA01 'measuring card', which takes in the spindle encoder and produces the -10-0-+10 for the Mentor drive. and parameter settings don't exactly conform to what I would expect for a 'three term control' . If I set the gain such that it gets close to set point but then stops not at set point, and manually turn the chuck from side to side, there is a wide 'dead band' either side of set point with no significant servo action, and I have to go through the set point very slowly for the measuring card to notice the set point position and confirm 'in position' to the 820T controller.
I've set myself two tasks today. Firstly to order up some 15 pin SUB-D plugs and sockets to make an interceptor cable for the encoder to check all it's bits are toggling (task complete !). Secondly to remove the analogue input to the Mentor spindle drive, and run it from a battery box to check it doesn't have any offset or deadband of it's own - (I have a little drive box somewhere made up when I built the 4th axis for the Partsmaster)
Meanwhile I've made up an Excel spreadsheet of the 17 parameters that I 'think' are involved so that I can keep track of what I've changed - I've been printing out a copy after each 'session' and time and data stamping it !
Post by: awemawson on November 02, 2018, 07:59:42 AM
Before 'the phone call' I did however have another play adjusting the M19 parameters and have found a setting that achieves 'lock' in that it arrives at set point. By adjusting the gain and seeing if the spindle under shoots or over shoots I was able to arrive at a compromise setting, but it is rather 'soft' and I think it is drifting as things warm up (not surprising). The gain setting is dramatically lower than my original parameters (170 as opposed to 2000) so I'm sure something is adrift elsewhere.
One handy feature is that I can send it to a particular angle, then using the PLC inbuilt monitoring facility find what angle it has actually achieved to let me know if undershoot or over shoot.
Complications this week end due to friends staying so little will probably be done, but it does provide another set of muscles to turn those cupboard over even if he is a septuagenarian like me :lol:
Post by: PekkaNF on November 02, 2018, 09:45:11 AM
The reason I though it has cascade controller is that in that era they often did and this comment
Also on the Mentor drive there are pots for tuning..I used them for setting the rpm after I had my motor re built..worth a try?
Other reason for pots are discrete error signals from analog system. Is there a feedback loop from the motor (position or current) in the Mentor drive?
Pekka
Post by: awemawson on November 02, 2018, 11:55:18 AM
It is, you are quite correct, a 'loop within a loop' as the Mentor is handling current through the armature to achieve a set speed looking at the tacho, and the 'Measuring Card' is controlling the analogue signal to the Mentor to achieve in this case a set position, but normally a set speed.
Hot off the press when the system has failed to achieve position and is in it's 'deadband' I can measure a signal in terms of a few tens of millivolts supplied to the Mentor to turn, and if I rotate the chuck by hand to the other side of the set point, the polarity of the signal reverses. So I conclude that the measuring cards KNOWS it's not where it should be, but the Mentor doesn't respond to such small signals. Now I assume (dangerous) that were the gain set higher, the 'error voltage' would also be higher, so the next job is to wire a DVM back from the Mentor to the console so I can see the effect of changing parameters in real time.
. . oh what fun :ddb:
Post by: cnc-it on November 02, 2018, 12:24:02 PM
Post by: awemawson on November 02, 2018, 12:57:22 PM
Yes the possibilities are endless once this facility is functioning faultlessly. I still need to modify the drive arrangement for the power tooling to actually be able to use it, but things are getting closer :ddb:
Post by: cnc-it on November 02, 2018, 02:38:50 PM
Post by: awemawson on November 04, 2018, 05:06:01 AM
Doing a bit more investigation, and armed with the recently obtained PLC program I can see a bit more of what is happening. A signal (I 114 bit 4) from the NC control, presumably derived from the 'measuring card' is provided to the PLC, where it triggers a 300 Milli-Second timer (T1) . If the 'in position' signal is still asserted when T1 expires the PLC acknowledges the end of the M19 cycle and applies the spindle brake.
As the servo system is in fact oscillating wildly either side of set point, and never 'on set point' for 300 mSec it carries on ad infinitum. Juggling all the various parameters previously detailed has failed to find a compromise setting. For all the world it is as though there is no damping on the system. I have also examined the acceleration parameters in the Mentor drive, and more than doubled the accelerate and decelerate ramp times with no effect on the symptoms.
I've shot a video to illustrate the point - note that as the updating of the PLC is 'sampled' the camera misses many of the brief bit changes for I 114.4
Also attached are screen shots of the relevant bits of the PLC program
Post by: awemawson on November 04, 2018, 05:17:38 AM
Assuming this machine was working when the back ups I'm using were taken then it's very odd that a parameter would need to be changed as they should be as they were previously, and one parameter (4270 Cut Off Speed for Gear 1) is set to it's original value of 5 the M19 system won't move at all ! Logically I would assume that some hardware has failed / drifted what ever but the bits involved as far as I can tell have been exchanged and then returned to no alteration in symptoms.
Post by: mc on November 04, 2018, 06:37:15 AM
If the PLC settings seem plausible and you're sure they're valid, what about the settings in the Mentor drive?
Post by: cnc-it on November 04, 2018, 06:55:19 AM
Post by: awemawson on November 04, 2018, 07:03:20 AM
I can't be absolutely sure that the gen that I have on the mentor is correct for this model (although I think it is) but it shows a 'bit read/write' parameter #167 'Ramp Enable' - but so far I've not found the way to change 'bits' !
On the positive side, the issue I was having with the pressure switch for clutch open / closed a few days ago seems to be solved by tweaking the pre-set for PS/5 on the closed side. Previously it wasn't changing state so would say both 'open' and 'closed' at the same time when actually open but now it does :thumbup:
Post by: awemawson on November 04, 2018, 07:06:01 AM
I had this problem on a Fanuc DC servo which was oscillating at stand still..it turned out to be a faulty servo drive top board (control card).. Encoder faults usually cause alarms and the motor to run away so can't see it being that.
No I don't think it's the encoder either, now that the PLC is actually getting the 'on set point' signal and I can monitor spindle rotatio in 0.1 degree graduations via the PLC 'Diagnose' function
Post by: mc on November 04, 2018, 07:38:25 AM
It could be it's running in a torque mode, in which case ramp settings are not likely to have much effect, as torque mode should bypass most of the speed control settings.
I'm guessing you've not got the proper manual for the drive?
Post by: awemawson on November 04, 2018, 09:42:39 AM
https://www.kollmorgen.com/sites/default/files/public_downloads/Mentor%20M3000%20manual.pdf
(Mine is the 6M4Q30MTD at 26.5 kW)
Although I've been adjusting the ramp times, it seems that ramps are not enabled on my drive, and the enable bit is protected by security codes though the ramp values are not
The bad news is that there seems to be a two level security code set to protect certain settings. Level 2 code is 149 - got that one, but the level 1 code is user settable and I have absolutely no idea what it is - only a 3 digit number :bang:
Post by: Pete. on November 04, 2018, 09:56:45 AM
Post by: russ57 on November 05, 2018, 05:30:47 AM
Then 123, 234, etc.
That's 20
Only 980 to go after that!
(a recent presentation I was at plotted bank card pins to a heat map. The 'hot' lines were centred around repeated digits and then 1-12 against 1-30, ie birthdays.)
Russ
Post by: awemawson on November 05, 2018, 05:59:59 AM
There is a parameter (#170) which is a one bit flag to say if the level one security code has been set. '1' = set but mine is '0' which means that only one code has been set.
However although putting the code '149' in parameter #97 for level 2 security enables the mode button that theoretically lets me change 'bit' parameters, and lights it's active light up, in practise I can't change the state of parameter #167 'ramp enable' from it's present '0' to the required '1' :bang:
Presumably it's hard wired or linked somewhere to prevent it. . . . oh joy the complications of life :scratch:
Post by: awemawson on November 05, 2018, 02:40:42 PM
Having done this it became obvious parameter #4010 wasn't really concerned - it is an offset to make sure forward and reverse speeds are the same, and a bit of experimental tweaking showed that actually it needed to be set to '0' - had been '2' and almost certainly has no influence on the oscillating issue.
Then I concentrated on parameter #4270 'Cut off speed for M19' - apparently the spindle is slowed down to this speed, and travels towards the set point until 'captured' by the servo action. Well it had been '5' in the parameters that I had been given, but the spindle never starts to move at all if set so low - 9 or 10 was the lowest at which I could set it and get the spindle to rotate towards the set point, so a bit of experimentation was needed.
Forgetting all about the M19 and simply issuing an M03 S10 command (M03 = rotate clockwise, S10 is the speed in RPM) gets the spindle slowly turning at 10 rpm and the input to the mentor is about 90 milli-volts. Issuing an M03 S5 the spindle won't turn, but the Mentor has an input of 41 milli-volts.
So I still think that the issue here is that for some reason the Mentor isn't responding to small inputs. Now the Mentor has an input range of -9.9 to +9.9 volts and it's internal A to D converter has a maximum count of 1023, making it's least increment 9.7 x2 / 1023 or 19.1 mV if I understand their description so would expect movement at 41 mV
Conclusion - well I don't have one, but I have learnt a bit more, but equally obviously there is more to learn :coffee:
Post by: mc on November 05, 2018, 06:21:34 PM
I'm assuming you can view the AD value on the Mentor some how going by that bit text?
Post by: awemawson on November 06, 2018, 11:28:58 AM
So first job, swap the cards again. At first I though that it was much improved, but measurements showed that the card had slightly different characteristics but the fault (oscillation when set to the correct gain) was still present.
I then set up the 'battery box' to drive the Mentor having added a passive 10:1 voltage divider to it to get low enough values with enough sweep on the pot. Essentially all it did was reproduce my findings driving it from the Measuring Card, although it did show a small offset with speed differing by a bit between forwards and reverse.
Then I decided to increase the field current in the Mawdsley DC spindle drive motor. I had set the field coil driver to 3 amps using my Fluke clamp meter - (this won't necessarily give an accurate reading due to the waveform of the current but relative readings should be OK). The motor isn't marked up with Field Current on the plate, just a voltage rating of 170. I'd chosen 3 amps to be conservative as the field coil driver was running very hot, but I've put a fan on it since then.
Again there seemed to be a marginal improvement, nothing stunning. Eventually I tweaked the gain and the 'target window' setting to give a working state just so I could seeing it positioning, and wrote a little diddy program stepping round in 45 degree increments. As the target window is now quite wide the positioning won't be particularly accurate, but it is 'sort of' working, but needs a lot of refining.
Have a video:
Post by: russ57 on November 06, 2018, 11:44:33 PM
Russ
Post by: awemawson on November 07, 2018, 02:37:06 AM
Post by: RussellT on November 07, 2018, 07:20:34 AM
I was catching up with all of this thread yesterday and at the end I was wondering how accurate this positioning could be. The inertia of the chuck/spindle workpiece must make it very difficult to stop it in an exact position by controlling the drive. Is it meant to be accurate enough to use the rotating tooling? Does the drive have a braking effect like a stepper motor? Surely it should apply the brake as it gets to the right position rather than wait for it to overshoot?
Russell
Post by: awemawson on November 07, 2018, 10:36:48 AM
If you look at post #541 on the previous page there is a diagram showing it's 'homing in' method - I'm not overly convinced that it's doing it though. Ideally the servo system should be tuned to just stop at set point. Once it has arrived in 'the zone' set by the positioning tolerance it applies the spindle brake and then will be fine for using the rotary tooling. Problem that I have at the moment is that I've had to set this tolerance to 20 1/11ths of a degree so nearly 2 degrees for it to work. The parameters that I got and were theoretically the original ones set it at 2/11ths of a degree so more tolerable.
My oscilloscope is playing up at the moment in the triggering department, but I have a replacement arriving hopefully Monday, and hope to be able to see the set point output of the measuring card as a dying or damped oscillation going forwards and reverse onto the spot. If you look at the video it does look as though this may be happening, certainly on some of the iterations.
For the record, yesterday I re-installed the original Measuring Card. Yes they have slightly different offsets which are levelled out with parameter #4010, but other than that I don't think that the card is the fault hence returning the original.
Post by: awemawson on November 07, 2018, 11:34:55 AM
A/ I know that the PLC needs the spindle 'on target' for 300 milliseconds to accept it's in position.
B/ The slowest I can reliably drive the spindle is 10 RPM or 10/60 revs per second
C/ At 1/6 RPS 300 milliseconds represents 1/6 x 0.3 = 1/20 of a rev for the 'target window' or 360/20 = 18 degrees
D/ My window is set to 20/11 = 1.8 degrees in the original parameters or a factor of 10 greater than the above
So the control embedded into the measuring card MUST anticipate the target point and leave the spindle to coast into the 'zone' possibly with minor corrections if it is going to over or undershoot, but it CANNOT simply steam into the zone and be there long enough for the 300 mSec that the PLC demands
. . . or maybe I'm missing something :scratch:
Post by: PekkaNF on November 07, 2018, 01:35:48 PM
Post by: RussellT on November 07, 2018, 01:54:24 PM
Thanks for the explanation.
That bit of maths is more or less what I was wondering about. I've also been back and looked at the diagram on post 541.
The diagram makes it clear it's supposed to overshoot - that makes sense as the inertia will change with the size of the workpiece.
The diagram only shows two iterations but presumably it will do as many as it takes or hunt if it can't stop in the zone - depending on the variable tv which is probably explained on one of the other images I skipped when reading the whole thread at one go.
I'm confident you'll work it out
Russell
Post by: awemawson on November 07, 2018, 06:06:09 PM
Post by: awemawson on November 07, 2018, 06:10:10 PM
From which OB that control loop is called? Normally only HMI and secondary functions are on the normal loop and tight controllers are put to 20 ms or such loop.
Pekka,
The actual control loop seems to be implemented in hard ware on the Measuring Card as far as I can tell but the boundaries between hardware and software are a bit fuzzy to me at the moment. I have no technical information on the Measuring card other than what I can infer by looking at it :scratch:
Post by: RussellT on November 08, 2018, 05:01:34 PM
On reflection I think that the angle measuring is working fine but it needs to go slower, or accelerate more slowly from the overshoot, it seems to me that it's the momentum of the system that's the problem.
Russell
Post by: awemawson on November 08, 2018, 05:08:43 PM
When I can 'scope the Mentor analog drive voltage triggered from the Drive Enable signal it should let me see if any actual control is being exercised at the few milliseconds of arriving at set point - I'm not convinced that it is!
Post by: RussellT on November 09, 2018, 05:58:54 AM
Interesting. I would expect doubling the approach speed to reduce the accuracy by a factor of 4 rather than the 10 I think you found in practice.
I am still wondering why it won't run as slowly and I am curious about the field coil current/voltage. I'm not clear why you can't measure the voltage - if a maximum voltage is specified then surely a method of setting up should be specified too.
Russell
Post by: awemawson on November 09, 2018, 07:34:50 AM
On the positive side my Tektronix 2465A arrived this morning to replace my ancient Tektronix 453 that I have been using for decades - it's a very good 'scope but the triggering isn't stable. Probably only a capacitor needs changing, but I wanted a faster one anyway.
Hope to get time over the week end to chase the servo problem, but people keep wanting me to mend things. Ironically I got a desperate email from the bloke I originally got the Traub CNC Lathe from. His Colchester Tornado 300 with Fanuc OT controller has developed a spindle drive fault and can I have a look please !!!! Poor chap has a production back log developing so I'll probably spend some time with him in the next couple of days.
Post by: awemawson on November 09, 2018, 12:28:47 PM
Then I tried the M19 issue and slow running etc. Characteristics WERE slightly different, but the minimum speed for instance was still 9-10 RPM.
Then I issued an M03 S1000 (spindle clockwise 1000 rpm - it started accelerating, the lights dimmed, and gave me a KTK Mentor Spindle Drive fault :bang:
So I wound the pot back to approximately where it had been, crossed my fingers and tried again - phew - back as before.
I do wonder if possibly there is something wrong with the motor field coils, as people in the know commented that they thought that the 23 ohms I'm measuring is rather low.
It is an enormous lump of iron to remove so I hope I don't have to go there ! It looks like this one on eBay but although the power rating is the same, the excitation and running voltages are different
Post by: RussellT on November 09, 2018, 05:57:03 PM
I'll be interested to see what you discover with the scope although I'm still thinking that getting the minimum speed down is going to be crucial.
Russell
Post by: cnc-it on November 10, 2018, 04:39:05 AM
Post by: awemawson on November 10, 2018, 06:23:43 AM
Got the 'scope on the analogue speed signal to the Mentor, triggered from the Servo Enable signal, and was horrified how much noise is superimposed on the base DC voltage. Not sure at this point if it is being picked up on the leads I'm using or if it is genuinely on the signal but I need to bottom it out. A 1uF capacitor across the scope terminals got it down to a level where I could see the signal but I'm still interpreting what I'm seeing.
Certainly it's looking vaguely like the diagram that I posted from the manual, but I still have work to do to see it properly.
Meanwhile if anyone wants my old Tektronix 453 I'm putting it up for grabs on the cork board, basically free, but make a donation to Eric to help with forum running costs:
https://madmodder.net/index.php/topic,12761.new.html#new
Post by: awemawson on November 13, 2018, 05:20:18 AM
Firstly I wired up a break out box to allow me safely to connect to the Servo Enable and Analogue signals for the DC Spindle servo system. As the X & Z axis signals and also those I wanted to hook into were all on the same 25 pin 'sub D type' the break out board was necessary to stop the X & Z servos slamming all over the place as I probed.
This allowed me to 'scope the signals and observe that servo action ceases at close to but not at set point - why ? Also the signal to noise ratio was pretty dire - for the small error signals down at the small increments involved ( about 45 mV) the noise was of the same magnitude. Some but not all this noise was being picked up on the twisted pair wires I was using and had a 165 uSec periodicy.
Then I turned my attention to the issue of the drive to the field coils. Plate on the motor says it wants 170 volts but I've never managed to achieve that without other problems ensuing. One big issue was not being able to measure current and voltage simultaneously and also have the fan mounted on the FXM-3 supply.
So I've added a DIN rail and brought the field coil connection out and via it, it such a way that they are both accessible and also there is a loop that I can get my clamp ammeter round. As an aside it has been suggested that the clamp ammeter, although being a true RMS one, won't show a correct current due to the chopped thyristor nature of the current wave form. Well I've disproved this, as it EXACTLY corresponds to my AVO 8 Mk 6 when both are measuring at the same time.
This also allowed me to see the 'field weakening' characteristics of the FXM-3 - to achieve high speeds the field current is drastically reduced over about 1500 rpm
So with the field set to 5.8 amps and resulting in 160.5 volts the motor characteristics were definitely different, but still it would not turn at the desired 5 RPM. Incidentally, this is 5 RPM at the spindle, the motor at this spindle speed in low gear needs to turn at about 22.5 rpm due to the 3.2:1 gear box, and belt ratios.
. . .why, oh why oh why ? A question that has had me racking my brain for months.
Post by: awemawson on November 13, 2018, 05:34:29 AM
. . . and guess what - I found that there was a parameter (#161) to 'Enable Standstill Logic' which if the speed is very low, backs off the thyristor firing angle all the way to prevent creep. BUT there was also a parameter (#162) that if #161 was set allowed creep speeds for shaft orientation well I never.
So quickly setting this parameter to '1' guess what - M19 works :ddb: :ddb: :ddb: :ddb:
Now it's not all plain sailing, as, although there is a method of saving the new parameter values to EEPROM, try as I may it isn't working, and the parameter reverts to it's old value on a power down / up cycle.
...BUT M19 IS WORKING :clap: :clap:
In the video the program is stepping round in 20 degree segments and I've set the positional accuracy to 2/11 ths of a degree as per the original parameters that I obtained
Post by: RussellT on November 13, 2018, 05:42:14 AM
Post by: awemawson on November 13, 2018, 07:58:38 AM
Turns out BOTH security codes need entering despite the flag saying one of them hasn't been set :scratch: Anyway, they are saved, AND I narrowed the location down to its finest setting of 1/11 th degree and sure enough it servo / homes in on it with the accuracy asked for.
Just need to find out how PK is doing 'down under' with that probe - he's gone ominously quiet for a few weeks, I hope he's OK.
Post by: seadog on November 13, 2018, 09:59:32 AM
Post by: Pete. on November 13, 2018, 11:40:08 AM
Well done Andrew!
Post by: PekkaNF on November 13, 2018, 01:35:45 PM
Interestin questions is why the servo amlifier had wrong parameter to start with?
Another interesting thing is what happens when you add inertia (large piece on the chuck). Will it overshoot more? In theorio it should not, because of the closed loop, but this "creep mode" sounds a little sensitive.
Pekka
Post by: awemawson on November 13, 2018, 02:38:26 PM
Yes very odd that just that one parameter on the Mentor was changed, and to do so you have to go through a procedure of setting other parameters to special codes. I very much doubt that the EEPROM had a one bit hissy fit so VERY puzzling.
Servo action seems pretty powerful now that the gain is back up to reasonable figures - I've tried stopping it by hand as it's on it's way to set point, and it isn't possible (and I have big hands!!!)
But . . . life is full of mysteries . . . such as what's happened to poor old PK, who seems to have vanished :bugeye:
Post by: cnc-it on November 14, 2018, 05:40:18 AM
Post by: awemawson on November 14, 2018, 08:50:31 AM
I KNOW that it worked when at Portsmouth University as the technician who swiped the probe and (bless him) had a copy of the parameters, sent me a dump of his back up including his programs. Some of these were for Lambretta crank flywheel balancing arbors that he was flogging on the side, and used the M19 spindle positioning to mill certain features :clap:
Sadly it's not a true 'C' axis in that it can just go to a position and lock on and brace itself for machining at that angular position, where as the Traub had a 'proper' C axis that could interpolate so you could machine as it moved, co-ordinating C, X, and Z.
I've been in touch with Mawdsley BER today, (the firm that grew from the ashes of Mawdsley Dursley that made the 27 kW spindle motor) as I would like to finally resolve what the field excitation SHOULD be. Apparently they do still have some records from that time and may be able to pull up a specification of it's parameters. They are searching their archive.
Post by: awemawson on November 15, 2018, 07:30:20 AM
Mawdsley-BER have dug through the archives of the original Mawdsley Dursley company that folded in the mid 1990's and found the original test documentation FOR THIS VERY MOTOR. Not one like it, or a generic specification, but the actual motor. Now I'm amazed that it's survived, and also very pleased as I now can definitely resolve the field coil current conundrum based on facts rather than guesses.
Copy attached
Post by: nrml on November 15, 2018, 08:16:10 AM
Post by: cnc-it on November 16, 2018, 05:57:02 AM
Post by: awemawson on November 16, 2018, 07:02:24 AM
Reading the Siemens manual for the 820T there seems no reason it couldn't have been a full on 'C' axis but that's not the way Beaver implemented it.
Post by: cnc-it on November 16, 2018, 08:41:17 AM
Post by: awemawson on November 17, 2018, 06:48:43 AM
But first I wanted to investigate a minor irritation in tool changing, where having issued a tool change command the tool disk would come forward unlocking it from its Curvic Coupling, and then pause for what seemed ages before rotating to the next tool position and re-clamping back on the curvic. now the PLC program, the code running in the SMCC turret control card, and of course the mechanics of the turret could all be possible culprits. I feared that the code in the SMCC card had possibly been corrupted. Having 'unclamped', the 'clamped' feedback switch opens and the 'unclamped' switch should close when the tool disk is far enough forwards for the Curvic to have disengaged, which triggers the SMCC card to using it's servo logic to rotate the turret to the next tool. Putting two channels of my 'scope on the 'Clamped' and the 'Unclamped' switches showed that despite the tool disk having travelled forwards it took a few seconds before the 'Unclamped' switch closed where upon the tool disk rotated as it should. This has eliminated the SMCC or PLC code as being an issue and either the switch needs adjustment, or maybe it's sticky.
I wrote a simple diddy to continuously change tools, and as it ran the delay reduced until it vanished, so either a sticky switch has now freed, or maybe warmed up. I'll have to let everything cool over night to see if it is still an issue. I had assumed that the two switches in question were proximity switches, but I don't now think that they are. The Patent Application refers to them as 'precision mechanical switches' - they are two wire, cylindrical and threaded like a proximity switch, but measure zero and infinity when closed and open under no applied power. In the circuit they are just in series with an opto coupler and current limiting resistor across 24 volts.
So on to the powered tooling. There are two issues:
A/ The Baruffaldi Powered tools have a different dog clutch shape than the machine drive spindle
B/ When a Powered tool is mounted, the faces of the two dog clutches are separated by 15 mm so wont drive anyway.
I had expected to have to dismantle the bearing housing for the drive spindle to remove the dog clutch and spindle, and make a complete new assembly, but it turns out that the machine dog clutch is just keyed to it's shaft and retained by a countersunk hex bolt, and I was able to withdraw it though an empty tool position.
Now the new dog clutch needs obviously to engage with the Baruffaldi ones, and be 15 mm longer (plus engagement depth). It would be a nice exercise to make on this lathe if the powered tooling was working, but that's a rather circular argument :lol:
Have some pictures
Post by: awemawson on November 17, 2018, 11:59:01 AM
Post by: awemawson on November 17, 2018, 03:05:03 PM
At the moment the drive dog is installed with it's shaft key but no retaining screw as I need to find a longer one. Amazingly it works. I suspect I could even do a bit of light milling with it, but probably won't.
Next task is to work out how to make a metal one. The teeth have a 12.5 degree taper when in lies the machining problem.
Post by: AdeV on November 17, 2018, 03:17:50 PM
Next task is to work out how to make a metal one. The teeth have a 12.5 degree taper when in lies the machining problem.
Two options spring to mind:
1) Tapered end-mills.... if you can get one with the right taper.
2) Do it on a manual machine with a rotary table, and have the head tipped over by the correct angle.
3) Mill the bulk of it with straight sides, then use a die eroder to make the tapers (if they can do that sort of thing?)
I'll stop there before someone does a Spanish Inquisition joke...
Post by: awemawson on November 17, 2018, 04:18:00 PM
The alternative but slightly more complicated way is to make a tapered slitting saw which would be more robust.
As a compromise I could make the protrusions slightly shorter radially thus increasing the gash root width.
. . . all suggestions welcome :clap:
. . . of course a 3D printer that prints in Bronze would work nicely :ddb:
Post by: nrml on November 17, 2018, 05:33:24 PM
Post by: WeldingRod on November 17, 2018, 06:55:58 PM
You could clearly 3d metal print them, probably under $100 each. Ideally key them to a stub shaft to save print volume and $$
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: AdeV on November 17, 2018, 07:11:04 PM
I really wonder how it was made!
I'd bet they're die cast. Not sure if they're machined afterwards, it would seem unnecessary, as the actual part-to-part wear would be minimal, since the parts aren't moving against each other once engaged; and having a super-precision fit isn't necessary.
Post by: chipenter on November 18, 2018, 01:42:36 AM
Post by: Pete. on November 18, 2018, 01:58:22 AM
Post by: cnc-it on November 18, 2018, 05:30:59 AM
Post by: awemawson on November 18, 2018, 06:00:10 AM
I've simplified and re-drawn the model this morning - hopefully this view will give a better idea of the tooth shape. I rather like the idea of lost wax casting it in bronze.
However it does occur to me that a plastic 3D printed one actually forms a useful safety 'mechanical fuse' in the case of jam ups, and it's dead easy to make another and re-fit it.
. . . I'm off now researching wax 3D printer filaments . . . . :coffee: :coffee:
Post by: mattinker on November 18, 2018, 06:07:22 AM
how about a three D printed core and cast in bronze using a fine petrobond sand mold?
Regards, Matthew
Post by: mattinker on November 18, 2018, 08:34:17 AM
A passing thought, cheers, Matthew
Post by: cnc-it on November 18, 2018, 09:21:55 AM
Post by: Pete. on November 18, 2018, 09:30:51 AM
Post by: DICKEYBIRD on November 18, 2018, 11:54:11 AM
Post by: awemawson on November 18, 2018, 12:02:17 PM
https://homeworkshop.org.uk/
Post by: nrml on November 18, 2018, 02:09:15 PM
Your idea of using a plastic printed part as a fuse is quite interesting. You could do a hollow print and fill it with an epoxy and metal mix for greater strength and use it as a semi disposable part.
Post by: philf on November 18, 2018, 02:18:58 PM
Post by: nrml on November 18, 2018, 02:22:20 PM
Post by: tom osselton on November 18, 2018, 02:41:45 PM
Post by: mattinker on November 18, 2018, 03:10:00 PM
I printed the second (Mk2) version earlier but not had time to try it yet, but also I've put an advert on the Home Workshop site asking for contacts who can cast bronze from an STL model - you never know! OK it's a bit of a cop out, but having lost wax cast myself years back I know the myriad of special bits and pieces you need to scrape together to do it. Also the special plasster has a short shelf life and only comes in big bags !
https://homeworkshop.org.uk/
It's not a cop out! To make a sand casting, it will need to be divided in two and given draft. This should be easy to do ! I attached a drwing in .png format, I can't see it in the preview.
Regards, Matthew
Post by: awemawson on November 18, 2018, 03:16:28 PM
As an aside I was amused to find when fiddling with the PLA print and the original Beaver drive dog that they tessellate. All Beaver have done is to put a drive dog on the drive shaft that is identical to the Baruffaldi one on the powered tools and presumably make powered tools with fittings like the one I've made. i.e. they swapped which shape was on which !
I've just printed an ABS one that seems quite strong
Post by: awemawson on November 19, 2018, 10:20:51 AM
It is a Euchner EGT1/4A5000 'precision mechanical switch' rather than a micro switch or proximity switch as one might have expected. It's end is a ball that bears on the turret shaft that has a suitable ramp shape so the the switch is made in the unclamped forwards position, and open in the clamped reverse position. I had already removed it, lightly lubricated it's shaft and replaced it, but the symptoms persisted. Putting my meter across it and hand operating to be frank there wasn't any stickiness apparent, so maybe it was just mal-adjusted.
The construction is awkward in that the adjustment collar and locking nut are not 'get at able' when the flange mounting is installed, so any adjustment has to be a long drawn out iterative affair, making a little tweak, re-installing, trying and then removing again for another tweak. The movement from open to closed is microscopic, so that the adjustment took many iterations :bang:
I have tracked down a very expensive replacement but hopefully today's tweaking session will have resolved the issue. Interestingly it's locking ring was by no means tight when I first removed it.
Post by: awemawson on November 20, 2018, 06:12:17 AM
First set back was no spanner to lock the ER32 spindle for tightening - well I had one but too thick to fit, so the usual 'go plasma cut one' - it may look spindly but that 6 mm steel is not mild steel, something much stronger .
Then I'd just got the 10 mm end mill snugged up when visitors descended, and absolutely no chance of tool setting with questions being fired over my shoulder - you need to concentrate to avoid breaking the Renishaw Tool Arm - I gave up on that !
So I just did a bit of manual milling putting notches at 45 degree intervals round the periphery of a 1" bar - majorly unimpressive but proves the ABS drive dog will transmit a bit of torque and that the M19 spindle positioning locks on adequately.
.. so proof of concept rather than a major step, and when the dust settles, probably in the dead of night, I'll get back to what I started out to do :med:
Post by: awemawson on November 21, 2018, 07:15:27 AM
Firstly the Ebay seller having failed to sell the Euchner EGT 1/4A5000 precision switch has accepted a more reasonable offer, so that is on the way from the states to hopefully just be a shelf spare and ward off any more 'turret unclamped undetected' issues.
Secondly I've had a very reasonable quote for casting a couple of drive dogs in bronze, so a pair of PLA models went in last night's post to Sheffield.
Thirdly, having a bit of piece and quiet this morning I've completed my cycle of tool setting without breaking the HPA probe - phew.
So on a roll, I decided to see why the remaining powered tool doesn't locate properly in the turret - I knew that something interfered, but couldn't remember what ! It turns out the the Beaver turret has a face mounted swarf guard in the middle that occupies part of the seating plane that the 90 degree tool wants to sit on - as it has an internal gear box it's more bulky than the others.
So there are three possibilities that I can see:
A/ Cut a bit out of the swarf guard - don't like this as it means when the tool isn't mounted swarf can get in
B/ Cut a bit off the 90 degree tool - a possibility as the interfering bit houses a micro positioning feature not used on the Bever turret.
C/ Sit the 90 degree tool on a 3 mm spacer - probably the easiest solution but I'll have to extend it's drive dog to suit.
Post by: awemawson on November 22, 2018, 08:23:41 AM
This needs doing as the existing cables (as previously mentioned) are just draped roughly in place and not in trunking despite there being a suitable run. Another motivator is that I need to re-fit more of the cabinet metalwork that guides swarf and coolant back to where it belongs, and when fitted, the trunking is no longer accessible.
First job - test fit the socket box that I made weeks ago - a bit of adjustment and it's fine :thumbup:
Then start exposing the trunking and removing as little as possible just to allow me to get a 'pull through' in place to draw in the new cables. I wanted to draw from the rear chuck end cabinet, through the cabinet behind the tailstock, and thence into the duct emerging below the Siemens controller. This allowed me to leave the reel of signal cable uncut and in the rear chuck end cabinet, to await a new piece of flexible conduit that I will install taking it to the place the OMM receiver lives on the left face of the enclosure above and behind the chuck. Currently this cable just hangs in the air unprotected :bugeye:
Now I have two types of pull through. Very flexible nylon cord intended for pulling 'singles' through round conduit, and pretty rigid fibreglass rods that screw end to end in the fashion of drain rods (but much thinner) - intended for poking wires across ceiling voids. I had to use both, using the rigid ones to get the flexible one into place, which then could draw in the cables. Didn't go too badly considering, but cable drawing is always easier if there are two of you (which there weren't !)
Post by: awemawson on November 22, 2018, 08:26:47 AM
Now I just need to remember how all this tin work goes together :scratch:
Post by: awemawson on November 22, 2018, 03:46:36 PM
But after a bit of cogitating a vague memory of a bit of 16 mm plastic coated steel Adaptaflex tucked away somewhere rose to the surface, so after supper I went hunting. A bit of rooting about in my 'may come in useful' store produced just over 4 meters and it was complete with the terminations - I guessed that I needed about 3 metres so luck was on my side :thumbup:
One end had a 15 mm bush termination and the other was 20 mm. As I intend to mount a 2" square galvanised 'adaptable box' on the existing 20 mm fitting on the chuck bulkhead and these boxes come pre-stamped for 20 mm holes, the 15 mm bush went in the cabinet base. I then pulled the conduit through the bowels of the machine and was able to follow the existing conduit that takes the Tool Setter arm cable and cut it off to length with the battery powered angle grinder. I then swapped the 20 mm fitting from the off cut to the bit being used.
Now as the signal cable is still on the reel, it's important before cutting to reel off enough for the job, but not too much to waste it. So firstly I pushed my flexible 'pullthrough' though the conduit - marked the nylon and then pulled it out as a measure leaving a conservative bit extra.
Then it was a case of re-threading the pull through from the far end, taping the signal cable to it, and pulling it through. VERY easy to pull the taped joint apart, especially as this conduit follows quite a contorted route, so it was a relief to see the taped joint emerge unscathed.
There was one bit of the plastic sheath of the conduit that had been scraped in a previous life, so I made that good with 'self amalgamating tape' (brilliant stuff that when stretched and wrapped bonds with itself into a solid rubber sheath)
So now I'm waiting for the 'adaptable box' to arrive. It will have a 20 mm hole bored in it's rear face which will be used to mount it when eventually the old cable is removed and the new made live.
But that won't happen until the OMM receiver and probe return from their antipodean holiday when PK has waived his magic wand over them.
Post by: awemawson on November 23, 2018, 10:09:11 AM
I still need to work out how to fix the lower 'L' shaped panel - the only access to screw positions is from underneath. Perhaps they were assembled on a plinth of some sort in the factory :scratch:
Then I made off the 24 volt supply to the 2 core cable laid yesterday, and tested it to the socket under the 820T controller
About this time the Adaptable Box arrived, so I drilled a 20 mm hole in it's rear, knocked out one of the 20 mm knockout locations and mounted it on the OMM signal cable conduit awaiting the return of the OMM
Post by: awemawson on November 24, 2018, 07:16:46 AM
Initially I reckoned that the two screws on the rear edge of the panel could just about be got at by offering the panel up at an angle, and using the flexibility of it's length to get my hands onto the allen key.
Then it struck me that if strong spring washers were fitted the panels would be clamped but the flexibility remain. In practice I used a compression spring for the joint as per the pictures and it worked very well.
Boring a 20 mm hole in the face of the panel at the front edge gave access to the one screw and threaded insert at that end of the panel, and having made an extended key I was able to do it up nice and tight.
The two vertical screws are inaccessible unless I once more remove the internal swarf / coolant guards, but as it is the panel seems firmly held. If in the future it vibrates too much then I can probably get at them that way to resolve the issue.
So as it is the only visible evidence is a 20 mm blanking grommet showing on the recently fitted panel.
Post by: awemawson on November 25, 2018, 09:28:05 AM
So in fact both cabinets were forklifted in (they are impressively heavy) lashed together on a pallet, and the slightly more presentable one moved into place at the tailstock end of the lathe.
Then it was a case of moving shelves vertically to give clearance as they swing, working out a suitable layout and drilling some holes to accept the VDI40 spigots and at least the tool holders are now stored safely :thumbup:
Much more to go in, but now time is on my side.
I'm working on dismantling the ER32 right angle powered tooling holder which is seized solid and needs a rebuild as did the two straight ones (they were bought described as such). So far I've got all the screws out bar two, which will be left soaking for a few more days in PlusGas. When I'm inside I'll put up a few pictures.
The right angled ER32 holder is probably the most useful of the three, allowing flats and grooving in the Z axis direction.
Post by: awemawson on November 27, 2018, 05:33:42 AM
I've been topping up the meniscus of 'Plus-Gas' on them whenever I walked by, and this morning I was down to the last two reluctant ones. Both 4 mm hex sockets in the head, so M6 CSK socket screws. One was so tight this morning that I got a full turn on a good quality 100 mm long allen key and still it wouldn't budge. The other one started rounding off the hex socket. Often reluctant screws can be freed by a few smart taps on the head, but these were in a slightly recessed situation, and my 1/4" hex drive bits were too short to avoid whacking other precision bits with the hammer. So I turned up a short bar end on the lathe, with a 7.1 mm hole in the end for the hex bit to sit in, and gave the screws a few smart raps with a hammer. They both then meekly unscrewed with no drama :ddb:
So the good news is that it's now ready to dismantle without as I had feared, resorting to either drilling them out or burning them out on the EDM machine - the bad news is that I am out for lunch shortly so cannot do it now (I'm told!) :bang:
Post by: awemawson on November 28, 2018, 06:52:20 AM
The main issue is the needle roller bearing that supports the input shaft - coolant has obviously entered and it has rusted up.There is an outward facing seal that presumably is the original problem having failed, but at the moment the seal and needle roller bearing are resisting extraction using my slide hammer bearing extractor, so it looks like a few more days soaking in Plus-Gas is called for.
Sadly this means I cannot yet order up the needed bearing and seal until I can make proper measurements
Post by: awemawson on November 28, 2018, 08:25:19 AM
Although from the rear the bearing doesn't expose anything to press against, the slide hammer bearing gripper when engaged presents the end of it's three fingers, against which a bar could be pressed.
After that it was no contest and out came the needle roller bearing and seal without even a squeak and the press didn't raise a sweat :clap:
. . .so clean up, measure and order hopefully this afternoon :thumbup:
Post by: awemawson on November 28, 2018, 12:31:19 PM
You may recall that the options were to modify the swarf guard, to modify the tool mounting face, or to mount the tool on a stand off washer and extend it's drive. As the carcass of the tool is now completely dismantled I could check what would be affected were I to slice a bit of it's base off to accommodate the swarf guard, and the answer is NOTHING that I care about :thumbup: Someone in the future putting it on a genuine Baruffaldi Turret might be a bit hacked off but the cut off bit has no function on the Beaver turret.
A tentative touch with a file showed me that it was mighty tough stuff, but machinable. I had feared that I might have to grind it, but M42 HSS coped OK at low feeds and speeds.
The swarf guard is a nominal 3 mm thick so I needed to remove 3.5 mm of thickness from a 2.5 mm x 5.0 mm area. But first I needed to sink the counter bores for the mounting cap screws by the same 3.5 mm. All went reasonably well, and after a bit of de-burring it's now ready for the bearings and seals and re-assembly.
So far it looks like the risk of buying a seized one might pay off - £24 for bearings and seals - with shipping the three tools (all seized!) were $272 so about £70 each. So about £100 all in for this one. A new 90 degree VDI40 ER32 power tool is pushing £2000 and working ones go for the wrong side of £1000 :bugeye:
OK mucho time spent, but that's the fun part :clap:
Post by: mc on November 28, 2018, 02:34:44 PM
having failed to find an 'O' ring 42 mm i/d x 46 mm o/d so 2 mm cord (if anyone knows a source please tell me)
Simply bearings have nitrile - https://simplybearings.co.uk/shop/p80828/2mm-Section-42mm-Bore-NITRILE-70-Rubber-O-Rings/product_info.html Viton - https://simplybearings.co.uk/shop/p513418/2mm-Section-42mm-Bore-VITON-Rubber-O-Rings/product_info.html and EPDM - https://simplybearings.co.uk/shop/p84828/2mm-Section-42mm-Bore-EPDM-Rubber-O-Rings/product_info.html
Certainly not the cheapest option, but when you only need one or two, it's cheaper than buying a big bag.
Post by: awemawson on November 28, 2018, 03:02:39 PM
... correction - no it was Bearing Boys I went first :bang:
Post by: awemawson on November 28, 2018, 05:10:57 PM
I made up a dinky little M4 slide hammer to try and get those two threaded dowels out. Only partially successful so far.
The first one shattered so must be very hard, but there was enough internal thread left to get the butt out. The second one is resisting removal so will have to wait until the morning.
(They are 6 mm x 30 mm tapped M4)
Post by: Pete. on November 28, 2018, 05:41:07 PM
Post by: awemawson on November 29, 2018, 03:59:12 AM
Usually you can heat things up to get a bit of differential expansion, but I didn't want to heat the casing up or it might distort, but then I remembered my Freezer Spray - used to identify intermittent heat problems with electronic components it allows me to dibble just a bit of the liquid onto specific places. Well the dowel has an M4 female thread, ideal for the straw :thumbup:
It took a couple of freezing sessions, but then very slight movement (Sharpie mark on dowel as indicator) and I knew it was mine.
(The frozen photo is posed - obviously by the time it came out it was nearly the same temperature as the casing block)
So now the next decision - oil or grease lubrication? Suggestions please.
Post by: awemawson on November 29, 2018, 05:41:28 AM
I decided to make them shorter at 20 mm (originally 30 mm). With the section that I milled off to accommodate the Turret swarf guard one had to be shorter anyway, and frankly the length doesn't add to their ability to locate the two half of the gear box as they are in shear in use.
The shafting must have been surface hardened, as although it's core is still pretty tough, starting the parting off, even with an inserted indexable parting tool was 'interesting'.
They are a nice pneumatic 'pop' fit :thumbup:
Post by: awemawson on November 30, 2018, 06:24:45 AM
Just reversing the sequence of pulling apart so not frightfully interesting. I packed the bearings with high temperature lithium grease in the end as that's what I used on the straight ones.
Still missing the large O ring that seals the cover for the taper roller bearing end float adjustment, but I mounted it up anyway and ran it a bit to 'run in' the bearings before final adjustment.
Post by: awemawson on December 01, 2018, 08:28:50 AM
After an initial oddity in Autocad where an unwanted circle wasn't displayed, yet was in SheetCAM, solved by "Eagle Eyes" David Judd who spotted a minute dot in the drawing that for some reason, like a collapsing black hole, the circle was compressed into - the spanner is made.
Actually it took more fettling than it should have - my drawing obviously wasn't spot on
Post by: awemawson on December 03, 2018, 03:02:51 PM
So, swiftly the capping was re-assembled and the unit re-installed. It's running a 'soak test' as I type.
As far as the turret goes all that remains now is to be brave enough to replace all the tin work - superstitious I know but I reckon that the chance of the turret giving me more problems will probably increase tenfold when the covers are back on !
Post by: awemawson on December 04, 2018, 07:22:08 AM
So all back together and I did a trial test of the powered tooling, which revealed a nasty rubbing noise that hadn't been there before the panels went back :bang:
Rubbing noise associated with the rotation of the powered tooling - drive shaft or drive belt fouling :scratch:
So the smallest of the covers that covers the powered tooling shaft and drive, which fortunately can come off without disturbing the other ones, had to be removed. This revealed that the end of the hub of the toothed belt pulley on the shaft was rubbing on the vertical face of the cover. I'm not really surprised at this, as this panel had obviously suffered badly in a crash under the previous owner, and I'd had to rather guess what shape it needed to be !
Need to decide on a work-around, but not now, it's time for lunch :ddb:
Post by: awemawson on December 04, 2018, 08:48:54 AM
If my sheet metal work skills were better I'd be tempted to make a completely new cover about 10 mm longer to give adequate clearance, as this one is pretty bashed about and wouldn't win any beauty contests ! But it is a very awkward shape to fabricate with lots of odd angles.
I've heard from the lost wax caster - apparently both drive dogs have come out OK, so that's good news but I've yet to see them.
Post by: vintageandclassicrepairs on December 04, 2018, 06:58:07 PM
What about cutting out the damaged section and welding in a new piece?
John
Post by: awemawson on December 05, 2018, 02:28:49 AM
I'm going to try and make a drawing of it and see if I can work out a bending plan. I suspect it'll be easier to make several sub assemblies and braze / spot weld them together. Looking at it, the original is made from two bits fixed together but increasing to four or five will help.
Post by: awemawson on December 05, 2018, 07:13:46 AM
Hang it I thought, plot it on the CNC Plasma Table tying a pen on it - then, no hang it just cut it :lol:
So I measured up the first part of the cover - the rectangular part that actually covers the belt - zapped it into Sheetcam and cut some steel, bent it up, then realised I'd marked and bent on the wrong side - it's inside out :bang:
Never mind, it'll be a practice piece for when I MIG weld it up .
Second cut on the CNC plasma table, then bent it the right way this time :thumbup: I see I've got the angle of one lug slightly wrong, so I've corrected the drawing but I don't actually think it matters much - anyway I could patch a bit in when welding up if it proves fatal.
Trying it out on the machine it fits at least as well as the original - no fixing holes yet so just wedged in with a screwdriver ! NB This one is 10 mm longer than the original to give extra clearance for the pulley hub.
So I think it probably is feasible for me to make another cover, it just might take a few iterations :lol:
Post by: awemawson on December 05, 2018, 10:09:59 AM
Fit up is not fantastic, but it should be OK for MIG welding if I can remember how :scratch:
Just the last little triangular bit to do now which probably is best done when the rest has at least been tack welded.
Post by: awemawson on December 06, 2018, 11:10:52 AM
So a few practices on offcuts and also the prototype cover that I bent up inside out, showed that with care it was possible, but mighty easy to blow a hole - this welder cheerfully blows hole in 6 mm plate !
Quite a bit of tacking a bit, bending to shape, tacking a bit more until there was enough done to try a test fit. Not too bad at all, just a trim off one edge. Then I had to create the triangular feature. The original cover was rather distorted, and a packing piece had been fitted to jump a gap, so by a little bit of re-design I was able to get a reasonable fit without the packer.
Then it was a case of grinding back the welds - not all the internal bits are accessible to the grinding disk but I don't suppose it matters much.
Then numerous fitting and removing and marking and drilling and fitting and marking . . .well you get my drift . . it was great fun transferring the holes from the turret onto the cover. I couldn't just copy the original as not only was it distorted, but the new cover leave 10 mm more clearance for the powered tooling pulley (which was where all this began !)
Eventually all screws were able to be fitted, and now it needs a good final clean up and a few coats of paint.
Post by: tom osselton on December 06, 2018, 02:22:05 PM
Post by: awemawson on December 07, 2018, 08:18:01 AM
Once Hugo was Zonked he was taken to the vets, given another jab that totally knocked him out, and left for examination while I had my hair cut. Nothing showing on x-ray or probing so stronger antibiotics for three weeks and rather a lot of spoiling.
This left me free to spray the first 'top coat' of RAL9001 on the cover which is now drying. Went superbly until a fly decided to fall on it, upside down with wings spread ! Carefully removed with pointed nose pliers, I hope the paint self smooths as it dries, otherwise there will be an impression of a spread eagled fly for posterity!
Post by: awemawson on December 08, 2018, 03:28:54 AM
I got a very slight bleed from the metal loaded filler I'd used to fair the cover in places, so having sprayed the top coat while it was slightly warm, I left it over night to dry. Thankfully the dead fly damage barely shows.
This morning I put it back in the kiln at the slightly reduced set point of 70 deg C and will leave it for several hours. Hopefully this will get the enamel as hard as the rest of the turret cover that I left for two months before re-fitting.
Post by: hermetic on December 08, 2018, 06:19:04 AM
Phil
Post by: awemawson on December 08, 2018, 09:34:57 AM
So after a few hours cooking I let the new cover cool to handleable temperature and re-fitted it, so that's a rattle can of zinc rich and two sprayed coats of coach enamel in 24 hours and as I baked it it was easily hard enough not to mark as re-fitted.
Glad to be able to report that the drive shaft no longer rubs on the cover - but then it shouldn't as the new one has an extra 10 mm clearance :thumbup:
Certainly a technique to consider in the future as usually it takes weeks for coach enamel to fully harden.
Post by: tom osselton on December 08, 2018, 06:28:11 PM
I was watching Forged in fire last night and one guy had hammer marks that were too deep on his blade and used powdered metal mixed with epoxy that worked good even in the bone chopping test!
Post by: awemawson on December 10, 2018, 05:19:07 AM
Today the postman brought me :ddb: THE BRONZE DRIVE DOGS :ddb:
They look splendid as cast - obviously they will require a little machining, at least on the bore, but the actual teeth mesh beautifully with their opposite number on the machine.
I was surprised to be able to see the actual build lines from the 3D printer, as crisp as the original though more visible due to the colour.
So I'll probably bore you to death with the fettling and machining over the next day or two
Post by: PekkaNF on December 10, 2018, 05:38:08 AM
.....
So I'll probably bore you to death with the fettling and machining over the next day or two
PLEASE!
There are way more nasty ways to go.... :lol:
Post by: b4dyc on December 10, 2018, 07:45:52 AM
So I'll probably bore you to death with the fettling and machining over the next day or two
You can keep trying but we are made of tougher stuff here :dremel:
Post by: tom osselton on December 10, 2018, 01:30:51 PM
Post by: hermetic on December 10, 2018, 01:39:19 PM
Phil.
Post by: awemawson on December 10, 2018, 02:11:13 PM
Well there's not a lot to come off - measuring the bore it's undersized by 0.25 mm so what happened to the expected 3% contraction? Obviously the bore has to be correct as it fits onto a shaft, but frankly little else is critical.
I decided first to fettle the outside of the 'barrel' so that I could chuck it up and clean up the drive dog end. This way I could (very carefully) chuck up on the dog clutch end to tidy up the bore. Now this set up is far from ideal, with too much overhang, so very light cuts !
So, dog clutch end is cleaned up, casting gripped by the newly machined bit, and the barrel 'trued up' using my roller nudge tool.
Post by: awemawson on December 10, 2018, 02:23:45 PM
Then the remaining artifacts of the pouring sprues where the PLA model was fixed to a wax 'tree' had to be turned off the end. These had protruded slightly down the bore.
Again a delicate operation, very easy to rip the casting out of the chuck :bugeye: Eventually I got down to the bare casting and could consider truing up the bore. Before that the shank needed cleaning up, then on to boring! First thing, set the boring bar accurately on centre using the "6 inch ruler" method. Then it was a case of tickling the bore down to a nominal 14 mm plus a tad of clearance - I bored to 14.05 - the shaft is 14.000 - so hopefully a nice push fit.
Post by: awemawson on December 10, 2018, 02:27:56 PM
Post by: awemawson on December 10, 2018, 02:35:39 PM
The keyway as cast was a tad over 3 mm so not much to remove - two passes did it, second with a packing shim.
Post by: awemawson on December 10, 2018, 02:38:01 PM
Post by: nrml on December 10, 2018, 03:21:33 PM
Post by: awemawson on December 10, 2018, 03:44:04 PM
http://www.geallencastings.co.uk/
Post by: awemawson on December 11, 2018, 04:58:02 AM
Again the bore only just cleaned up.
Post by: PekkaNF on December 12, 2018, 07:58:47 AM
Awfully little material over the key way. Is that fusible or just no more space?
Post by: awemawson on December 12, 2018, 10:41:05 AM
Between a visit to the dentist and a friends birthday lunch I managed to fit one of the bronze drive dogs - went in as a nice snug fit :thumbup:
Post by: PekkaNF on December 12, 2018, 04:40:42 PM
I thought the same Pekka, but we are not talking huge torque, just light milling.
Between a visit to the dentist and a friends birthday lunch I managed to fit one of the bronze drive dogs - went in as a nice snug fit :thumbup:
Sweet!
Post by: awemawson on December 12, 2018, 04:50:08 PM
. . . but I do have not only a bronze second one as a spare, but several ABS and PLA ones that actually seem to work OK !
Post by: nrml on December 12, 2018, 05:08:54 PM
Post by: awemawson on December 12, 2018, 05:22:42 PM
Post by: awemawson on December 14, 2018, 05:48:09 AM
Hopefully I'll never need it, it can stay as a 'shelf spare', but being rare as hens teeth it had to be had :ddb:
Post by: awemawson on December 14, 2018, 10:31:23 AM
I could just use a 'jump up' sleeve to fit one of my centres from my 3MT manual lathe but it adds length and a bit of flex, so I rejected that in favour of a dedicated one. The Beaver tail stock is equipped with a screwed ring arrangement to eject the centre, so the one I chose didn't need to have one fitted.
Recently a VERY nice Rohm 504 AC Mk4 Indicating Centre popped up on eBay in the UK as 'spares or repairs'. 4 MT, rated at 3500 RPM, and 900 kg end thrust, it has a pressure gauge indicating the end thrust while in use. Slight snag - the tip didn't look too good, and the gauge assembly was in bits with the glass and possibly other bits missing. This is a VERY pricey rotating centre, cheapest I've found new is 800 Euro's plus VAT and carriage. :bugeye:
Having successfully negotiated away from the sellers optimistic asking price this let it fall into my clutches arriving this morning by DHL.
A quick appraisal showed it was far better than I had expected. The tip was just discoloured and not worn, the reportedly 'stiff to rotate' feature was the front oil seal, and the gauge looked OK although there was no seal for it's input, nor as mentioned any glass.
I assume that there is a piston / cylinder arrangement acting on a very strong spring within so as the load increases oil is forced out to deflect the gauge.
Peering into the hole in the body of the beast where the gauge spigot engages, it looked obvious to me that an O ring should be in it to be squashed by the spigot to form a seal. About 6 mm x 3 mm at a guess.
It just so happened that years ago I made a mistaken purchase of 1/4" x 1/8" bore O rings from RS Components, not realising that they came in bags of 100, so I got 100 times as many as I'd expected, and they've been falling out of my 'O Ring Tote' ever since :ddb:
Popped one into the hole, offered up the gauge, screwed on the bezel, and it seated nicely. The bezel bears on two flats on the gauge on a step in it's internal bore, so that were the glass in place it would take no load - handy for replacement, but also means that I can test it without the glass.
Post by: awemawson on December 14, 2018, 10:39:09 AM
I could just put it in the lathe and crank the tail stock forwards by hand, but I had no idea if anything would fly off or break. I decided to make up a simple adaptor to pop over the 'point' to allow me to load it up in my hydraulic press under controlled conditions and me a fair way away holding the umbilical controls !
Amazingly it works - spot on, I took it to half and then full load, no leakage, no nasty noises, all fairly undramatic I'm glad to say.
So now I just need to source a glass. I've decided to use actual glass rather than acrylic, as it will otherwise easily be scratched. So where do you buy a 1.5 mm thick by 32.3 mm diameter tough watch glass - well eBay of course and should arrive before Christmas :ddb:
Post by: seadog on December 14, 2018, 11:04:42 AM
Post by: awemawson on December 14, 2018, 11:53:16 AM
I need to make a pin spanner to dismantle it from the front. There is a cross section of a non indicating Rohm centre on their web site but I've not found one yet of this specific indicating one.
Post by: awemawson on December 15, 2018, 07:09:22 AM
Works very well, but I must remember that it only needs 1 ton on the hydraulic press to get a nice deep impression of my date stamp - that was 2 tons and it's too deep and has spread the centre bit of the spanner so it looks swollen !
Post by: WeldingRod on December 16, 2018, 11:09:14 AM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on December 16, 2018, 11:58:28 AM
Post by: awemawson on December 17, 2018, 09:38:44 AM
Reconciling myself to making a wooden box that stopped when I realised that my bottle of 'Resin-W' PVA glue was congealed beyond rescue- so what to do :scratch:
Then I remembered an Acramill collet chuck box - no idea what happened to the chuck, I think this came as part of a job lot with no chuck, just the collets. So the remaining collets were ejected into my box of Acramill bits and the box 're-purposed'
A simple wooden divider with a hole in it to take the business end, an other with a slot (so it would go in) for the 4 MT shank, and a third loose bit to stop the centre sliding up and down. Then the two shaped dividers had a recess cut in them to hold the nose spanner.
I'd intended to screw through the box into the wood, but realised that it would very likely split. So rightly or wrongly I chose to use 'structural adhesive' Horrid messy stuff and I totally failed to tidy it up neatly. Not really happy with the result but at least the centre won't now roll off the bench!
Long term I will probably re-make the dividers in an engineering plastic that will take a thread, so can be safely screwed from the outside of the box.
Post by: seadog on December 17, 2018, 09:53:08 AM
Post by: awemawson on December 17, 2018, 02:08:10 PM
Time to sort out the coolant: There is an external motor / pump unit rated at 20 litres / minute that sits on the coolant tank, draws up through a mesh filter, then passes coolant to the machine though a 125 micron hydraulic filter.
I started by undoing the filter housing - it was well choked with plastic swarf. It will clean up reasonably but I'd like to put a new one in. The actual element is a UC.R.76115 and googling so far has found that for what they are, they are a silly price (£30 plus the VAT). Hopefully I'll turn up a cheaper alternative. The only 'special thing about it is that the inner mesh
perforated tube is stainless to avoid rusting.
I intend to prove the pump and filter 'off line' using a bucket rather than fill the tank with it's 95 litres and then find the pump doesn't work!
All the nylon re-inforced hoses will be replaced as they've gone rather sticky with age.
Post by: seadog on December 17, 2018, 02:56:32 PM
Post by: awemawson on December 17, 2018, 03:23:08 PM
https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/1757CA3C753793E880257796002FC871/$File/HYSOL%20EXCEL.pdf
But Castrol have now 'renamed' this product 'Castrol Alusol A' which reading it's spec is aimed at aircraft aluminium alloys and doesn't include grinding in it repertoire. So are they the same or not :med:
https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/6C1589B46849053B80257796002F5B93/$File/453700_XI_en.pdf
I think some searching questions aimed at Castrol are called for :hammer:
It's rather important to me that any new stuff is mixable with what I have as machine sumps get topped up rather than wholesale replacement - this stuff is expensive. At well over £100 per 20 litre drum (of which I need two :bugeye:) I need to get it right!
(Later edit)
(Oddly those links require you to log in, but a google search for them doesn't so I'm attaching them as pdf files )
Post by: seadog on December 17, 2018, 03:38:36 PM
A good job it wasn't renamed Anusol A :D
Post by: awemawson on December 17, 2018, 03:45:36 PM
Post by: awemawson on December 18, 2018, 07:36:35 AM
First I explored, and then removed the remnants of the input filter that sits in the tank - most of it was missing! It looks from the remaining stub, that it was a standard 3/4" BSP screw on hydraulic tank filter, reduced to 3/8" BSP - presumably to benefit from the larger area of exposed gauze :med:
Post by: awemawson on December 18, 2018, 07:56:17 AM
Lots of bubbly noises as the pump pumped air into the bucket. Gingerly lowering the new input hose into the bucket an impressive flow of coolant started circulating at a great rate of knots!
OK how do I stop this without getting soaked? - Pull the input hose out of the bucket making sure that the output stays submerged, hold it vertically until all has flowed that will, then high tail it to the front of the machine and hit the stop switch !
In celebration I've ordered the 'in tank' filter that I illustrated above, and also the 125 micron inline filter element. Still no definite answer on the Castrol coolant. Speaking to their local rep it turns out the the Hysol Alusol A has itself been replaced with something with loads of letters details of which he is emailing me (as at the time he was driving and I was cooking bacon and eggs :clap:)
Hoping this afternoon to replace the remaining hoses as I think I have the correct stuff in stock, then I need to pay attention to where the coolant is injected into the turret. There seems to be a plain ended threaded tube projecting towards the rear face of the tool disk. When a tool change is commanded, the whole tool disk moves forwards to disengage its curvic coupling, then rotates and clamps back to it's previous axial position. Now on the Traub lathe the equivalent bit was made from PTFE which presumably had a bit of 'give' in it for a good seal. This one looks to be just steel on steel. I will try and remove the nozzle and see if I can perhaps let an 'O' ring into it's end, or even make a PTFE cap to go on it's end.
Post by: awemawson on December 18, 2018, 10:13:07 AM
Anyway I took out the old and very sticky hoses replacing them with identical length new ones. I suspect that that long curly one is intended to be tethered to the rear cover when it is re-installed leaving sufficient for the carriage to trundle up and down the ways without tearing it off. At first glance it seems too long, but it can always be trimmed.
Post by: awemawson on December 18, 2018, 11:26:03 AM
A bit of fiddling about with grips and a bit of Plus-Gas and we have a moving spring loaded nozzle again :thumbup:
Look carefully and you can just about see it move on this short video
Post by: awemawson on December 19, 2018, 10:39:25 AM
I'm blessed with three different methods for mounting the tubes across my range of VDI40 tool holders.
1/ The genuine Beaver ones have a sphere, through bored 6 mm, locked in place by a countersunk hex cap screw allowing the ball and tube to be swivled to point where you want it.
2/ The non beaver holders have a similar ball, located by friction, and tapped in the bore M6 x 1
3/ The Baruffaldi Powered tools have a 1/4 BSP port intended for 'Loc-Line' fittings. Now this always raises an issue because 1/4 BSP loc-line connectors are rare beasts, they are usually 1/4 NPT 18 TPI as opposed to 19 TPI for BSP
The four genuine Beaver tool holders I have equipped with bits of copper pipe to direct the flow.
The four threaded sockets raise a problem. Threading M6 x 1 on the end of soft copper pipe is a no-no as it buckles. I had this issue with the Traub and bought some 6 mm heavy walled steel tube but can't for the life of me find the remnant :bang: I may silver solder a thread on the end
For the three powered tools I have ordered up some Loc-Line and the 1/4 NPT connectors are going to be warmed and gently eased into the 1/4" BSP hole - dead easy to sheer off the fitting doing this, but it does work 'sort of'. I'm actually tempted to make up some 1/4" BSP compression fittings and do it in copper as a better engineering solution. we'll see . . . :med:
Post by: awemawson on December 20, 2018, 06:09:00 AM
So last night I fired off an order the RS for some 1/4" x 6 mm compression fittings which duly arrived today in the same Parcelforce van as the Loc-Line :clap: Never mind, it will undoubtedly be used in a future project!
Fitted them this morning and it makes a nice neat job of aiming the coolant at the cutter.
Now I need to devise a way of making the M6 threaded nozzles for the other tooling. I notice that there are firms selling a 'lollypop' of a ball on the end of a tube, but I'm not sure how my friction mounted ones will stand up to removal and re-fitting. Also were I to go this way I might just as well drill the spheres that I have out to 6 mm !
Post by: awemawson on December 20, 2018, 07:19:38 AM
Setting a scrap of 1.6 mm welding rod upright in the vice I threaded the components on ready for silver soldering and had at them with my propane torch.
Hasn't come out too badly considering the crudity and will probably work, I just need to produce an other five or six of them.
Meanwhile I placed an order for the coolant which should arrive shortly after Christmas
Post by: awemawson on December 20, 2018, 09:45:44 AM
(Looking at the picture I must remember to put the missing VDI40 blanking plug in!)
Post by: awemawson on December 20, 2018, 11:58:55 AM
By program :
M08 turns coolant on
M09 turns coolant off
. . .or at least they should :scratch:
There is also a pair of push buttons on the front panel for 'coolant on' and 'coolant off' . Now these buttons work just fine. Ploughing through the PLC logic I can see the bit where it handles the coolant contactor, and there is a mystery latch that has to be set to enable the M08 /M09 commands to operate the relay. But for the life of me I can't see what is supposed to set this latch
There is a bi-stable that represents COOLANT within the PLC logic, and writing a loop to turn coolant on, pause 5 seconds then turn it off, then pause 5 seconds and go back and start over I can see the bi-stable changing state but it's output doesn't get to the output for the relay due to the mystery latch - all very odd :scratch:
Post by: awemawson on December 20, 2018, 02:03:09 PM
The Siemens 820T control console has masses of push buttons, the vast majority of which are not used. However it turns out that next to the two button that turn coolant 'ON' and 'OFF' which are clearly labelled, is a third, that with the aid of a torch and magnifying glass, you can just make out 'COOLANT AUTO' :lol:
. . . . obvious in'it :clap:
Post by: tom osselton on December 20, 2018, 02:17:37 PM
Post by: awemawson on December 21, 2018, 04:37:04 AM
Of that row of 23 buttons only 7 are used. (as far as I know !!!)
Post by: awemawson on December 21, 2018, 05:09:54 AM
Might as well screw it in. I wanted to set it's depth so that the tank didn't have to be absolutely topped up and yet it could draw coolant, but I hadn't realised that the vertical threaded 3/8" BSP pipe that sets it's depth actually locks with the hose fitting outside the tank pre-determining it's depth.
Sorry about the second blurry photograph, I ran out of hands !
So now I'm just waiting for the 125 micron in line filter element and the coolant itself to start splashing white milky coolant everywhere :clap:
I must investigate the door interlock. Things aren't supposed to happen with the door open but they do at the moment. I did a minor investigation when I got the machine delivered, as the door contact was one thing that I could operate and measure, so I know the switch itself is OK but someone has nobbled it 'down the line' !
Post by: awemawson on December 21, 2018, 08:30:29 AM
It turns out that the key-switch on the front panel inhibits certain setting changes when LOCKED and enables operation with the door open when UNLOCKED. So I suppose it's a sort of maintenance facility built into the machine.
In a fit of enthusiasm I've started to try and get the black overspray off one of the Versatool cabinets. In the picture of 'as it was' it's sitting on a pallet by the way.
When it's all off I'll 'compound' it with Tee-Cut but at the moment I can't find my compounding pad !
Carrying on with the enthusiasm theme I've ordered 10 metres of 25 mm x 6 mm sticky backed neoprene firm foam tape to go on the rear surfaces prior to the cabinet covers going back. There are vestiges of some previous seal but completely crumbled away.
Gosh if the covers are nearly ready to go back I must be getting to the top of this particular mountain!
Post by: awemawson on December 24, 2018, 03:48:50 PM
I have a PlusTek flat bed 'book scanner' that allows scanning close to the fold between two pages, which helps enormously, but it still take an age. I've now finished the Operations bit, and have the Programming part to do. It scans in then OCR's the images producing searchable .PDF's which is a very useful format - much quicker to find a reference than in the hard copy (although I much prefer reading hard copy)
Now I need to remember how I managed to stitch several .PDF's together before (I did the same exercise for my Wire EDM machine manuals a few years back - indeed it's why I got the scanner in the first place)
Post by: Pete. on December 24, 2018, 04:13:56 PM
Post by: awemawson on December 24, 2018, 04:20:22 PM
Later edit:
Yes, still have the code AND it still works - thanks for reminding me :thumbup:
Post by: awemawson on December 28, 2018, 10:01:57 AM
I gave up searching for my 'compounding pad' to finish off the paint on the Versatool cabinet, and ordered another one which came today - so the cabinet got cleaned up and the black over spray is a thing of the past. :thumbup:
Also in today's post was the replacement glass for the Rohm tail stock pressure gauge so that got fitted.
And in a fit of 'tidying up' I replaced the covers on the Hydraulic pump / tank assembly and the main spindle motor and it's cooling motor.
(apart from one M6 x 65 mm socket cap screw which was missing when the machine was delivered and is now on order !)
. . .still waiting for the coolant . . .
Post by: russ57 on December 29, 2018, 03:54:21 PM
I hope you are scouring the 'good home wanted' ads for the next exciting saga.
Russ
Post by: awemawson on December 29, 2018, 04:31:02 PM
Fear not, there are things on the 'back burner' that may well come to the fore:
a/ I have a vacuum former - quite a nice one and fully working before putting in storage, but has suffered over the last decade - I'll have to pull it out and give it a bit of titivation and then probably sell it as I've not used it recently
b/ Then there is the 100 kW Induction Furnace just waiting to be brought back to life. It's in the 'welding shop annex' which is actually a fireproof building that I built specifically to house such hot things, but the space is currently bally cold being winter, so it may have to wait until the spring
c/ Then I have a humongous TIG welding machine that needs an extremely large electric feed that I've never powered up in the five years I've had it - apparently it has an intermittent fault, and I have a feeling I know what's causing it, but I need to extract my digit and get on with it !
So sorry you will continue to be harangued by my goings on 'down on the farm' , and actually I will now have a bit more time for the workshop, as I've sold all my sheep and now just have the pigs (the wife has retained her Jacob's sheep)
Post by: Muzzerboy on December 29, 2018, 05:08:44 PM
Post by: russ57 on December 29, 2018, 11:05:12 PM
Since it is a combo machine I also have no mma or plasma cutter...
A Rossi super p200iS, probably sold under many labels. Just a baby compared to the ones just mentioned.
If anyone has a circuit or service manual....
Russ
Post by: awemawson on December 30, 2018, 05:09:14 AM
Interesting stuff in the pipeline! What make is the TIG welder? My Miller / Interlas 320ABP weighs about 400kg and you could almost climb inside - sounds similarly unwieldy. Takes something like 70A from 240V single phase on full chat.
It seems that it is a "BOC TransTig 350" but is not in the best place for photographs, as it is facing the wall !
Post by: AdeV on December 30, 2018, 07:29:57 AM
In fairness, this is a brilliant restoration, it makes me want to get on with the Mazak but I've just got too much other (non workshop) stuff going on, and I'm not entirely sure I've got the patience or methodological mindset to get mine working properly.... although I'd really like to try.
Post by: awemawson on December 30, 2018, 07:53:10 AM
No plans to dispose of it, and loads still to learn using it. But then I had no plans to dispose of the Traub
But I must dig out the Denford Mirac and sell it as I don’t need two CNC lathes I think
Post by: awemawson on January 02, 2019, 07:22:15 AM
Why is it a problem? Well when it covers the full surface of the coolant it prevents oxygen entering, and this promotes the growth of anaerobic bacteria which is a 'bad thing' generating bad smells and potentially bad corrosion products.
You can reduce the problem by adding tablets that chemically kill the bacteria, or a 'fish tank bubbler' that oxygenates the coolant, but far the best thing to do is remove the oil before it becomes a problem.
So how does the skimmer work: Dead simple really. A belt, driven by a slowly rotating motor, dips into the tank, with a heavy roller on it's lower end to keep the belt reasonably taut. As the belt rotates, the surface oil tends to stick to the belt, and towards the top of the belt is a scraper that removes it into a duct leading to a 1 gallon can.
Well get on and fit it then! - I can't - it WASN'T delivered today as promised :bang:
But RS did at least deliver the Harting heavy duty 'HAN' plug and socket that I decided to use for it, as this style was already in use on the machine, so I did get that fitted in readyness.
I'll have to trepan a large hole in the top of the coolant tank, but that had better wait until the skimmer arrives so that I can check sizes, as I'll have to fabricate a bracket for it anyway.
(Picture here is of a similar belt skimmer that I fitted to the Beaver Partsmaster CNC Milling Machine)
Post by: AdeV on January 02, 2019, 01:00:35 PM
Last time I put any in the Bridgeport CNC sump was, um, 3 years ago? Maybe 4 years now. No bad smells yet! (and it still looks like it should do, hasn't gone lumpy, etc.). I've not got a skimmer either, so there's definitely a layer of tramp oil on it...
Post by: awemawson on January 02, 2019, 02:30:38 PM
At least the Castrol products abound with specifications and data. My local oil supplier (Rye Oils) will sell me extremely cheap 205 litre drums of 'General Use' soluble oil, but I avoid it for the same reason.
My advice is to somehow get rid of your tramp oil, you may not yet have suffered any ill effects, but they are very well documented.
What Brix do you dilute it to ?
Post by: AdeV on January 02, 2019, 03:48:23 PM
I'm sure it's fine Ade, but a brief bit of Googling doesn't reveal any actual product data re sulphur, chloride or silicone content etc nor does anything make reference to grinding operations :scratch:
The same place sells another soluble oil suitable for grinding - it's a bit over £100 for 25l, but I've no experience of that one.
I'm sure if you e-mailed the shop they'd send you technical data, MSDS, etc. Personally, I've never bothered, and it seem to work fine.
What Brix do you dilute it to ?
Brix?
I put about 20l of water on 5l of oil, so around 10% or so.
Post by: awemawson on January 02, 2019, 04:01:00 PM
Brix is the concentration scale for things dissolved in water - commonly sugars but in our line also soluble oils. You measure it with a refractometer by placing a drop of the mixture on a glass window, trapping it with a cover and measuring the refraction by looking through the calibrated eye piece.
(Very handy for checking the concentration as time goes by and evaporated water has to be replaced - I had to add 6 gallons of water the the Partsmaster yesterday :bugeye:)
Post by: awemawson on January 04, 2019, 08:14:27 AM
(Incidentally having replaced the wire rollers on the Migatronic welder has made a world of a difference to it's performance)
The base, which I cut on the CNC plasma table so I could radius the corners and cut a slot for the vertical, is held down on rare earth magnets on Delrin stand offs that allow me to adjust the depth of immersion.
Today I assembled it, put the correct plug on the cable, trepanned the hole in the tank, and installed it with a 5 litre catch can.
The belt is rather creased from being crammed into it's box, and the drive is a bit hesitant at times, but when it gets soaked in coolant I'm sure it will be fine.
. . . .coolant . . .that reminds me . . .it hasn't been delivered yet :scratch:
Post by: tom osselton on January 04, 2019, 04:26:21 PM
Post by: awemawson on January 04, 2019, 05:23:33 PM
By the way, the barrels of coolant arrived gone 5 pm this evening so guess what I'm doing tomorrow :lol:
Post by: Johnny Bravo on January 05, 2019, 03:29:59 AM
Post by: PekkaNF on January 05, 2019, 04:45:13 AM
Pekka
Post by: awemawson on January 05, 2019, 06:24:29 AM
Pekka, the belt material looks like the backing used for rolls of silicon carbide abrasive, but without the abrasive of course. Reading the instructions, the green side should be inside touching the roller surface, so I turned it round, but the one on my milling machine has been the other way round for the last five years and is working fine !
So I set off today to dilute the coolant and pour it in. Bucket chemistry (literally) - I was aiming for Castrol's recommended 9% concentration. Easy really with a 10 litre bucket with a calibration line, and a lab pyrex 1 litre calibrated flask.
Initially I just put 10 litres in, and left it for a while, as I needed to build confidence in the tank base. When I grit blasted it and re-painted it all those months ago, there were a few corrosion pits that might have had pin holes. I'd rather have 10 litres on the floor to mop up than the 95 of a full tank !
All seemed well so I went ahead aiming to put 70 litres in, then stop and check the dilution with my Refractometer. However my 10 litre bucket sprang a leak at 30 litres and I had to revert to a 9 litre one that I had, just making the maths fractionally harder !
Getting to the 70 litre target, I then set the machine pumping coolant around to make sure it was reasonably mixed, as of course each 10 (9) litre batch will be slightly different.
Amazingly the refractometer showed bang on 9% Brix - sorry about the photo, but you try holding the refractometer against the iPhone and pressing a button - I ended up using my tongue to press the button :ddb:
So then I took the tank up to 'almost full' and left it pumping. The Tranp Oil Skimmer is working overtime, as of course over the months that I've been working on the machine, the automatic slide lubricators have been faithfully pumping slide way oil to the needed place every few minutes. I've seen (so far) moths, flies and small spiders dragged out by it so they've obviously been having a party in the tank !
Post by: awemawson on January 09, 2019, 10:32:25 AM
Wanting to add a 'Wash Down' facility - ie a simple hose gun off the coolant pump to manually wash chips away and clean up a work piece, I decided that I needed a pair of valves acting in anti-phase. One in line from the coolant pump to the Tool Turret, and a second one from the coolant pump to the gun of the wash down facility.
Dead easy with relays and buttons, but I thought, why the heck should I be adding MORE buttons when the 820T is crawling with ones that have never been implemented, and there's a perfectly good PLC program running that I aught to be able to modify.
Having identified the input addresses of the front panel buttons that I wanted to use (I96.3 and I96.4) and found two spare 24 volt digital outputs (Q2.6 and Q2.7), with a bit of trepidation I started poking about in the PLC program live on the machine.
Now despite months of work learning about the PLC, it's 'STEP5' programming language, managing to down load and produce a paper copy of the PLC 'ladder logic', I have only before passively read what is in it and never attempted to edit, alter or add it it. So this is a first.
STEP5 is a very frustrating program to use to program, however today I've managed to add another 'Rung' to the ladder (Segment 173 to be pedantic!) and amazingly it works :ddb: :ddb:
Trivial in the extreme as far as the logic is concerned. One button sets an S/R flip flop, the other button resets it, and it's output controls one of the valves. Now I need to add subtleties to it, interlocking so it will only work when the door is open, will not work when the chuck is spinning or a program is running, and ensuring that when one valve opens the other closes, but that's finessing that can be done at my leisure, the point is I've proved that it's possible and I've managed to do it - hence the warm glow.
. . . back to reality - I need to go muck out and feed the pigs !
Post by: PekkaNF on January 09, 2019, 01:16:58 PM
You can go down to nearest town with zipper open carrying a poster: I KNOW HOW TO PROGRAM S5 AND MAKE CHILDREN! :D
Pekka
Post by: tom osselton on January 09, 2019, 02:33:18 PM
I haven’t had a swollen head since that frying pan incident! :wack:
Post by: awemawson on January 12, 2019, 05:38:07 AM
I've been looking for suitable 17.5 mm pipe clamps to hold the extra pipes when the 'wash down' goes in. Couldn't find any so I printed some on the Cetus 3D printer in ABS at 99% fill
Post by: awemawson on January 13, 2019, 09:53:44 AM
Again absolutely trivial code, but I discovered an interesting and useful STEP5 quirk while doing it. You can display the ladder diagram rung by rung, and set it to display the status of each node in real time. So in the following picture of segment 173, the door interlock node is displayed in GREEN as the door is shut and it's contact active - quite handy for fault finding I think.
So two rungs added:
Segment 173 is an R/S flip flop set and reset by the appropriate panel buttons, but inhibited by a closed door or a running spindle, and is reset by the general 'Reset' button on the machine. If the flip flop (= Flag 140.2) is set, Q 2.6 drives the 'wash down' solenoid.
Segment 174 merely takes the flag 140.2 and if it is NOT set activates Q 2.7 which drives the solenoid valve directing coolant to the turret and it's mounted tooling.
. . .seems to work so far . . . :scratch:
Post by: awemawson on January 23, 2019, 05:43:00 AM
Dry assembling them and hanging them roughly in the place where I want them is the easy bit. The conundrum is to work out how to actually secure them such that not only are they firm enough to resist the inevitable vibration, but also such that they can be easily removed for maintenance.
All the joints will be sealed with Loctite 542 'pipe seal', which means that their rotational orientation can be set without making them actually tight until the 542 sets.
However there is nothing at all on the valves to fix them with. I've considered various methods - 3D printing a 'cradle' - bending up brackets for the top and bottom 'nozzles' to go through - a bracket with hole that gets interposed between the nozzle thread and the valve - all have their pros and cons.
My current proposal is to braze a lump of brass to the central 'Tee' piece with ears to fix to the machine chassis, and hang everything off that.
Post by: seadog on January 23, 2019, 06:20:32 AM
Post by: awemawson on January 23, 2019, 07:35:17 AM
I found a suitable bit of 4 mm brass plate, marked it out, drilled it, cut it to size (always cut last - more to hold when drilling!) and then brazed it to the Tee piece.
I decided to use Cu-Phos brazing rods for two reasons - a/ I have a bag of it, and b/ it doesn't need any flux when brazing copper or brass - handy stuff but DON'T use it for boiler making. My supply is left over from years back when I was making up custom fittings for the 100 kW induction furnace.
So, wire them together, and have at it with my propane torch. I use MIG welding wire - should be soft iron wire but I don't have any. If you, like me, use MIG wire, anneal it first by flashing the torch over it getting it red hot. In the as supplied state it's too springy and is difficult to handle. Also getting it red hot forms a nice oxide layer which prevents the brazing sticking to it.
Not the neatest item but certainly functional :thumbup:
. . .just need now to mark out the machine frame, drill and tap it, and fit the hoses and wire it up
Post by: awemawson on January 23, 2019, 11:28:19 AM
While the Loctite was setting to the 'handling' state, I drilled a pair of 20 mm holes in a suitable place for cable glands to bring the digital output wiring to the solenoids.
Once the plumbing assembly had been screwed onto the machine I was able to pull cables through the existing ducting and wire up the coils of the solenoids. Slight delay while I fed the pigs, then a grand tidy up and test. I'm pleased to be able to report that the front panel buttons, via the new PLC rungs, and out via the digital outputs, do precisely what I wanted. At power on, the upper solenoid is driven porting coolant to the turret. When the 'Wash On' button is pressed the upper solenoid is released, and the lower one is driven porting the coolant to the wash down hose. If the 'Wash Off' button is pressed, or the lathe sliding door is closed, the solenoids revert to putting coolant to the turret.
. . . sorted :ddb:
. . . except . . . I've not yet put the hoses on, I'll leave it until tomorrow for the Loctite 542 to fully harden before putting fluid though the assembly to give it it's best chance of not leaking !
Post by: awemawson on January 24, 2019, 05:51:18 AM
As the carriage moves both in Z and X it's important that there is enough slack in the hose to the turret for it not to pull itself off, so careful checks and a bit of trundling up and down got me to what seems the optimum length.
So time to test: firstly proving that the feed to the turret still works was successful, with only a minor leak requiring a Jubilee clip to be moved up the barb connector a bit and re-tightened.
Then time to prove the wash down gun. With the gun locked open I pressed the 'Wash On' which gave me a very impressive coolant jet well up to the task :thumbup:
This is when the problem occurred :bugeye:
Releasing the lock on the wash down gun, thus turning off the flow, produced a VERY impressive fountain of coolant from the back of the machine. Rapidly turning off the pump and going round the back it was obvious what the cause was. The high pressure from the pump was easily overcoming the Jubilee clip on the wash down gun hose at the valve end.
Now in hindsight this was predictable. The coolant pump isn't a normal vane pump that can run happily into a shut valve, it's a gear pump, and develops HUGE pressure when blocked - my fault entirely, I should have realised :bang:
I think the solution is either a pressure release valve on the pump output direct to the tank, or possible just a simple mechanical valve allowing some flow even when the gun is closed.
However, having mopped up the flood, now I need to pack up the Racal RA17 communications receiver, as my roll of bubble wrap has been delivered. At least it will give me some thinking time.
Post by: awemawson on January 24, 2019, 10:44:08 AM
Firstly, I seems that the hose that blew on it's barb fitting is 5/8" bore Not 1/2" as marked :bang: but was on a 1/2" barb, so not really surprising that that is the one that went first. I replaced the barb.
Secondly, as I was working out where to put a Pressure Relief Valve and what thread sizes I needed, I looked closely at the pump and guess what I found - a Pressure Relief Valve. It was screwed all the way in so at it's highest setting, but I don't know what pressure that corresponds to as it is un-calibrated.
I unscrewed the PRV as far as I dared so it is at a much lower setting and sure enough all works, and when the Washdown Gun is closed off you can hear the PRV working - so a result :thumbup:
Sometime I'll put a pressure gauge on it and see what pressure it opens at. The wash is noticeably less vigorous.
Post by: Pete. on January 24, 2019, 05:02:06 PM
Ever since then I have always favoured using those o-clips instead of jubilees wherever I can.
Post by: Pete W. on January 25, 2019, 05:43:13 AM
Many years ago, when I lived in Romford, I organised a guided tour of the Dartford Tunnel. (It was before the bridge was built - the Dartford & Purfleet Joint Tunnel Undertaking was the power in charge then.)
As part of the tour, we were taken beneath the road deck in one of the bores. The whole tour was very interesting and the staff spared no effort to make the tour a success.
It's many years since I crossed the Thames there so I'm well out of date with developments. Pete, why were you removing the road deck? Temporary or permanent?
Post by: awemawson on January 28, 2019, 06:58:23 AM
Knowing that the turret had been driven into the tail stock at some time in its history, making that big dent in the cover that I had to re-fabricate, it was unlikely to be 'spot on' .
Two things are necessary:
Firstly that the tool disk front face is at right angles to the spindle axis, and parallel to the X axis movement.
Secondly that the bore that accepts the VDI tool spigots is accurately in line with the spindle centre line when X = 0 . This measurement can be 'out' either as X=0 has been incorrectly set for movement up and down of the X axis slide, or more likely that the turret rotational alignment has shifted in a crash.
Today's job was to check and correct the tool disk parallelism. I decided to use my Tesa electronic DTI, as it has the advantage of being able to be set to increasing sensitivity as the process proceeds, and also to have a long enough cable to be positioned at the operators console from where I'm moving the X slide.
The turret is held on by three massive cap head screws at the top and also the bottom, the bottom ones requiring that I remove the power tooling drive cover to gain access.
Loosening the screws then setting them to 'just nipping' I then installed the Tesa DTI head on a magnetic clamp on the face of the spindle (having locked the spindle to prevent rotation). Sure enough there was quite a large discrepancy as the tip of the DTI moved across the face of the tool disk - I didn't take accurate measurements but it was of the order of 5 thou in 2 inches! Then much like you would align a vice on the table of a milling machine, it was a case of judicious tapping with a soft dead blow hammer aiming to rotate the turret on it's mounting face with the X axis slide. After several iterations I got the error down to about 1/10 thou in 2 inches. Tightening the clamp bolts increased this to 2/10 but that's where I left it.
To check the rotational location of the tool disk I need to rig a ground pin in one tool position and swing the DTI round it. The Tool Disk is bolted to the Hurth Coupling that actually fixes it, and it will be a case of slackening the bolts and a bit more iterative tapping !
If I can find a suitable pin, then that's possibly a job for this afternoon.
Post by: awemawson on January 29, 2019, 07:30:41 AM
The turret on indexing brings the tool disk forwards, thus disengaging the front Hirth coupling and engaging the rear one that then allows the servo motor to rotate the turret to it's new position. Once there the system drives the tool disk back onto the front Hirth coupling locking it in place. BUT, it is not reliably getting to the right place, so when the Hirth moves to engage, it's two parts don't mesh correctly leaving the tool disk forwards and the system locks up awaiting the 'turret locked' signal, which it never gets.
Now it's a complicated control system. The PLC requests a tool change from the Baldor SMCC servo card, which controls the turret motor and takes in inputs from the Optical Incremental Encoder that is mounted on the servo motor shaft. Within the turret there is an Index proximity switch telling the SMCC card where zero is. As far as I can tell the program in the SMCC card knows how many encoder counts it needs to move to the requested tool position and homes in on that.
Now previously I had thought that the four way proximity switch block (that also monitors tool position) was what was being read by the servo, but now I realise that it cannot be, as when the tool disk is moved forwards for rotation, so are the protrusions on the 'hedgehog' that the proximity switches sense and are out of range. These four proximity switches are a confirmation to the PLC that the SMCC card has done what it was asked to do!
So I've been doing tests this morning, having first removed all the sheet steel covers off the turret to gain access yet again :bang:
It turns out that the direction of rotation of the turret influences things, so going from tool 5 to tool 9 might work fine, but going from tool 9 to tool 5 will often give the error.
Things that could influence this are possibly a loose encoder coupling, or a bias offset on the servo system. Now currently getting at the encoder coupling to check its fixings is proving a problem. I'm guessing that there are one or two grub screws on each side of it, and there are screw capped holes to give access at both ends where I expect the screws to be, but the shaft of the motor needs turning to get at the screws, and the motor has a brake that is engaged with the power off. Head scratching time working out how to just power the brake, as it's too dangerous working with my head round the back of the turret if the main servo systems are alive :scratch:
It probably just needs a 24 volt supply to pull the brake off.
As for the servo offset, this harks back to something I thought I'd noticed months ago when I first got the turret semi-working, but I'm short of documentation on the Siemens Simodrive AC servo card.
Post by: awemawson on January 29, 2019, 10:03:50 AM
The access hole is maybe 10 mm diameter, facing downwards at the tail stock end of the turret assembly. Trying to get a mirror and a torch and a screwdriver co-ordinated proved impossible. I got out my Wi-Fi endoscope for a good view of the coupling, but there wasn't room for the endoscope and the screwdriver at the same time. I then tried taping the endoscope to the screwdriver with the screwdriver leading the adventure, but the image got very confusing as I had to move the screwdriver. Eventually, with the endoscope porting the image to my iPhone, which was balanced inside the machine, and holding the camera bit close to the hole with one hand and poking with the screwdriver with the other EVENTUALLY I got it on each screw in turn and checked their tightness.
All very confusing, as the image has a significant delay, so you are seeing what you did, rather than what you are doing !
Anyway they were as tight as I could get them, so it was probably another red herring. Have a video of the coupling rotating
Having done all that I now cannot reproduce the fault :bang:
Could be that things have warmed up a bit, but really I'd like to try and set the servo card so it balances nicely. I'll have to get some numbers off the card and go googling
Post by: awemawson on January 30, 2019, 11:49:58 AM
However at the moment I can't reproduce the fault :bang:
I've increased the servo gain slightly, and subjectively the motion seems a bit crisper, but maybe that's wishful thinking !
All this started when I was aligning the tool turret, and the tool disk face is now nicely set to match the X axis, but the tool turret rotation needs re-setting. My measuring dowel came in the post today, and it's out by 5 thou in about 5 inches, so not an enormous error. I now need to slacken the bolts securing the tool disk to the Hirth coupling, and gently tap it round however many degrees that error corresponds to, and hope that this time I don't expose more problems :clap:
Post by: awemawson on January 31, 2019, 06:51:40 AM
The two part Hirth (or maybe curvic, documents refer to it by both names) coupling has one part fixed to the turret centre spindle, and the other bolted to the tool disk trapping a flange on the spindle. By loosening the ring of eight M12 socket cap screws it is possible to tap the tool disk round to adopt a changed angularity relative to the spindle. But what to use as reference :scratch:
With a 'normal' lathe tool holder clamped in the turret, what we are aiming for is the reference mounting surface for the lathe tool to be parallel to the X motion of the carriage. Fortunately I have a brand new, nicely ground holder that I mounted in position 6 (arbitrary - doesn't matter where!) with a balancing one in position 12, though this one wasn't brand new and it's surfaces weren't quite as pristine!
Then setting the electronic DTI in the chuck, placing the finger on the relevant tool holder surface, rotating the lathe spindle to give me a zero, then locking the lathe spindle, I could track it up and down the surface seeing a conssiderable discrepancy. (about 30 thou in the 100 mm length of the holder)
Now I had prior to this slackened off the ring of eight M12 cap screws and semi re-tightened them. It's worth noting that the internal hydraulic 'lock' cylinder is also holding the tool disk against its flange. Initially I thought that I was going to fall at the first hurdle, as the bolts were massively tight. Eventually bringing out a 4 foot tube as a 'torque amplifier' they all came loose, but I was grateful that my Allen Key was a decent quality Unbrako that stood up to the punishment.
Tapping the tool disk round with a brass drift, resetting and starting over, after several iterations I got the indicated error down to zero with an FSD of 1 thou on the gauge, which is quite pleasing. Rotating the turret round to the balancing tool holder and measuring that gave me an error of just under 2 thou over 100 mm which I put down to the fact it's a well used holder, but that discrepancy wouldn't be the end of the world.
I'd put all the removed tool holders in a 'Tote' to keep them safe, and when I went to move them out of the way realised how amazingly heavy they are - they ended up staying put! It made me have a greater respect for the servo system that rotates the turret.
Now I will have to go through the tool setting process once the tool holders are re-mounted, but that's fairly automatic now.
I did have one peculiarity during the process described above. I got to the stage where the adjustments had been completed, so the last action was to jog the tool holder past the DTI which was fine. I then left everything powered up while I boiled a kettle for a visitor. When I came back the machine looked ok, all lights correct, but it wouldn't jog. Even powering down and trying to go through the initialising process the issue persisted. Hunting for the error I removed the axis enable, axis brake and drive over travel relays relays one by one reinserting them as I went. After that everything was normal so what had happened I don't know. Obviously something to watch out for.
Post by: awemawson on January 31, 2019, 11:05:17 AM
I weighed the tote of tool holders that I'd removed, 39 kGs plus the two I used for measurement that were still on the turret at 3 kGs each so 45 kgs being rotated by that poor old servo unit. :bugeye:
No wonder it needs a reasonably high gain setting.
I was just about to re-run a previously run job to see how things measure up, then JUST stopped myself remembering that all the sheet metal covers are still off the turret and need re-fitting to keep the swarf, and probably more important the coolant, out of the works. Might get half an hour or so tonight to refit them as I believe I'm an orchestra widower this evening !
Post by: awemawson on January 31, 2019, 04:28:51 PM
All seems to work. I ran a simple job (a shaft with two diameters and radius-ed transitions). Have a very splashy video. As is usual with these things the coolant stops you seeing much !
Post by: Pete W. on January 31, 2019, 04:55:55 PM
Have you got room to fit one of those rotating glass disk gizmos (I think it's called a 'Kent Screen') on the inside of your door?
Post by: awemawson on January 31, 2019, 04:59:29 PM
Post by: PekkaNF on February 01, 2019, 05:51:35 AM
...
I decided to use my Tesa electronic DTI, as it has the advantage of being able to be set to increasing sensitivity as the process proceeds, and also to have a long enough cable to be positioned at the operators console from where I'm moving the X slide.
.....
That is very usefull looking indicator, small to install and display is a separate unit. I have been eyballing lazilily some LVDTs and diplays, but the (mitutoyo) price has been a deterrent.
Tried to google canditates, but I'm failing with proper search words.
Post by: awemawson on February 01, 2019, 07:19:47 AM
I have a mains operated version that's a bit big and clunky but takes the same pin out sensors, and also takes two of them for high and low limits in a production set up, lighting red and green lights for 'go' and 'no go' !
. . .I've only got pictures of it's internals when I got it and mended it ! It uses PROPER electronics not this modern stuff :lol:
Post by: awemawson on February 02, 2019, 09:18:50 AM
Still on a brighter note I've bottomed out why the machine just stopped and refused to do anything the other day. Absolutely NOTHING to do with the relays that I'd suspected. It was the key switch on the Operators Panel :clap:
It turns out that the slightest touch on it, and it operates. Now this key is intended to stop people fiddling, so inhibits many functions. Measuring the contacts, even when 'closed' I'm getting 600 milliohms which for a gold plated contact is far too high. I think some of the Lithium corrosive gasses got into it from the original problem.
EBay has sourced me a very nice looking replacement, allegedly Swiss made so hopefully reasonable quality, brand new for £3.20 :thumbup:
Post by: Pete W. on February 02, 2019, 02:40:45 PM
Never, ever, tease Andrew - he always has the resources to call your bluff!! :D :doh: :D :doh: :D :doh:
Post by: awemawson on February 06, 2019, 06:15:44 AM
The extra depth proved not to be a problem, and the only complication was that the junction where the front and rear of the switch body clip together was within the depth of the (plastic) panel stopping the 'ears' of the clip expanding far enough to retain. After a stern word it gave in and got fitted and soldered in.
I decided not to fit the cover flap as they are a flipping (or flapping!) nuisance.
While the panel was off I replaced the D-25 socket retainers with the pillar style. The originals were for sliding clips whereas my cables have the retaining screws. Another job ticked off the list - I'd planned to do this wees ago.
Post by: awemawson on February 06, 2019, 06:58:10 AM
Operating the switch to prove it inhibits the operations that it should, it fell apart in my hands :bugeye: The main body of the switch has a threaded portion that has cracked.
Switch removed, wires soldered together and hole left in operating panel until replacement received :bang:
(And no, it wasn't over tightened !)
Post by: Alphawolf45 on February 06, 2019, 10:33:04 AM
Post by: AdeV on February 06, 2019, 02:38:38 PM
Operating the switch to prove it inhibits the operations that it should, it fell apart in my hands :bugeye: The main body of the switch has a threaded portion that has cracked.
Nothing to do with...
After a stern word it gave in and got fitted and soldered in.
...was it?
:lol:
Post by: awemawson on February 06, 2019, 03:04:15 PM
Post by: charadam on February 06, 2019, 04:30:52 PM
Post by: awemawson on February 07, 2019, 03:05:39 AM
I did however yesterday print a tubular spanner in ABS to make fitting the next one easier. Just a castellated tube. I'll pop in a picture when I'm on a proper PC not this iPad.
Later edit: photos added
Post by: awemawson on February 08, 2019, 05:18:03 AM
Post by: awemawson on February 10, 2019, 08:35:38 AM
There are three Siemens Simodrive servo systems in this lathe, all the same except that the drive cards have different current capabilities. X is a 20 amp, Z is a 30 amp, and the turret is a massive 40 amp. It came as a surprise that the turret was the biggest.
Having yet again pulled the covers off the turret to take a picture of the servo motor specification plate,needless to say in the most inaccessible place! I've been able to compare the settings on the card to the Siemens manual, and they correspond exactly. Then I thought that I was on to something. The same servo motor that indexes the turret also drives the powered tooling, and I thought that I had noticed some discrepancies in actual speed (measured by a reflective rpm gauge) and the commanded speed.
So this mornings job was to tabulate the errors and try and work out what was going on.
I had a reflective sticky tab stuck on an ER32 collet nut. 100 rpm gave 350, 200 rpm gave about 400, 1000 rpm gave approx 1600 - what the heck?
Then, in a flash of inspiration I wrapped brown insulation round the collet nut, and stuck the reflective tab onto that. Guess what:
100 =100, 200 =200 etc etc up to 2000 rpm - absolutely spot on all the way through the range. But this itself is rather peculiar, as I've been fiddling with the Tacho scaling pot so I'd not expect it to have been so accurate :scratch:
The main issue seems to be getting the twelve tools on the turret properly balanced - apparently unbalance is more of a problem than total weight (45kg) of the tools I'm told.
I was going to try and make up a spreadsheet of the various tool weights and try shifting them about to get a balance, then I realised, as the geometry of the tools differ, the point at which the weight acts also differ.
Then I was going to make an analog of the tool disk in aluminium plate with a central bearing, and manually shift tools about until it balanced, rather like balancing a grinding disk.
Then I thought . . . this is getting silly . . . .go and have a cup of tea . . . . :coffee:
. . . so that's where I am now :clap:
Post by: awemawson on February 10, 2019, 10:05:16 AM
Of course I left it running for ages and it never failed :bang:
Post by: WeldingRod on February 10, 2019, 03:57:00 PM
Or, just take the weights and match the heaviest ones across the disc.
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: Pete. on February 10, 2019, 04:08:20 PM
Post by: mc on February 10, 2019, 05:04:21 PM
Surely if it's on position, it should pull straigt in onto the coupling with no rotation?
I can't remember how you said the position is measured, but I think I'd be nudging whatever it is around so it's pulling in straight.
Post by: awemawson on February 11, 2019, 05:34:27 AM
The index position is sensed by a proximity sensor looking for a notch. When the turret is initialised the SMCC card seeks the index position and homes on it - you can see the drive dog for the powered tooling rotate, then finding the position go off it and back on for accuracy.
Now it's rather difficult to see what is attached to what within the turret, but certainly at the point that it is seeking Index the front curvic is fully engaged and the rear one dis-engaged. The listing of the SMCC program that I have shows that there are 2000 encoder points between tool positions so when it is asked to change tools it seeks Tn x 2000 pulses.
But what sets the relative rotational positions of the Index to the other bits I am not clear. The Index proximity sensor is in a tapping in the turret casing so not rotationally adjustable.
This morning with the machine cold it resolutely refused to run the Turret Exerciser program without failing. It was OK on anti-clockwise moves but failed to seat the curvic on clockwise moves.
There is a setting ('Offset') on the servo card that so far I have failed to adjust by the book - it requires that certain wires be removed and links made, but the terminal numbers in the book don't all correspond to the printed numbers on the card. Basically you enable the drive, and also it's 'inch' mode and apply 0v to the analogue input, and tweak the multi-turn offset pot until the servo motor stops turning. Now just using the system rather than links, for 0v input the servo motor IS stationary.
However this morning with the program failing every time, I thought - what the heck - tweak it. I gave it 5 turns anti-clockwise (I think that it's a 20 turn pot) and guess what, the program instantly started working. So somehow I need to bottom out the wiring and get the offset accurately set.
It is very difficult to see if the clockwise last minute rotation that Moray noticed is still as consistent as it was - the camera angle is such that the tool disk is moving away at an angle anyway as it seats so it looks to rotate anyway - I shot another video so I'll let you decide as it's easier to see in the video than in real life.
I've also included the Turret cross section for reference.
Post by: awemawson on February 11, 2019, 06:02:17 AM
I get the impression that there is still a slight settling clockwise on clockwise tool changes, but not so much on anticlockwise moves :scratch:
Proof of the pudding will be tomorrow morning when it's cold again I suppose
Post by: awemawson on February 11, 2019, 12:56:08 PM
Excel spreadsheet. Weigh all your tools, do the combinatorial thing (12 factorial or 12 × 11 x 10 x...) for lines, 12 columns for.positions, then do a net moment calculation for each opposite pair, and sum it up. Lowest net moment is your best choice.
Or, just take the weights and match the heaviest ones across the disc.
Sent from my SAMSUNG-SM-G891A using Tapatalk
Not quite so easy Rod, as the mass of the tools act from different points due to their differing shapes, which is why I went on to consider the 'analogue' approach using a mocked up disk.
Post by: awemawson on February 12, 2019, 03:08:30 AM
I'm pleased to report that it's passed the 'cold test' this morning, behaving right from the get go :thumbup:
However last night I went through the various circuit diagrams and worked out the anomalies in the numbering scheme for the 'offset' adjustment, how to disable the servo brake (not mentioned in the book procedure!), and to the disable the X & Z axis so they cannot move. So if I get time this afternoon I'll see if I can perform the procedure.
Post by: hermetic on February 12, 2019, 04:43:02 AM
Phil
Post by: awemawson on February 12, 2019, 04:55:52 AM
If you watch the last short video "Turret Exerciser Better Angle" you'll see that the servo hunts either side of set point then when on station fires the lock solenoid pushing the two parts of the curvic into mesh, and at that point there is very little (if any) relative movement implying that not only was it at set point, but that the set point is correct.
Post by: awemawson on February 13, 2019, 07:53:51 AM
Well, the answer is, yes, my turret exercise program still runs ok, but you can see the previous symptom of a bit of movement as the coupling goes home. What would you do with an unbalanced car wheel - you'd fix lead weights to balance it - so why not?
First need to work out how much by weighing the tools
Post by: awemawson on February 13, 2019, 07:58:26 AM
Trying the machine with the turret now balanced, bingo the curvic coupling is again seating nicely, so a successful experiment
Post by: WeldingRod on February 13, 2019, 09:55:57 PM
Sent from my SAMSUNG-SM-G891A using Tapatalk
Post by: awemawson on February 14, 2019, 07:09:00 AM
Post by: cnc-it on February 14, 2019, 11:06:44 PM
If I'm correct it's pot R125 (x axis) , R225 (Yaxis) , R325 (ZAxis) Kp (n) on the AC drives. The manual says turn the gain up if you have inaccurate positioning.
Post by: cnc-it on February 16, 2019, 11:39:19 AM
https://drive.google.com/file/d/1_fheJGFmyK5layWUKvz-G2y88A2-c6_o/view?usp=sharing
Post by: awemawson on February 16, 2019, 11:47:28 AM
Post by: cnc-it on February 16, 2019, 12:34:17 PM
Post by: JeffK on February 19, 2019, 11:07:57 AM
I have been following your progress and applying some of your fixes / checks to a Beaver TC20F I bought around Xmas (fool I hear you say!!)
I have got so far but have run into a few problems. Unlike your machine mine came to life fairly easily as it had been kept in a workshop but had not
turned for a couple of years. I can now jog the x and z axis and also the spindle but have not managed to do a zero return on it yet. I am not very
PLC proficient but did have some success with various overtravel issues etc.
My main problem is when I start everything up I get a x axis and z axis Pulco error which will clear when reset then following that I get the following:
'EX05 - The T-word is illegal, only t-words between 100 and 1299 are valid, present tool no. is 11'.
I jog in the negative direction as per instructions in the basic handbook I have but when I switch to zero return I get a second message:
'EX30 Axis on reference trip, select 'jog mode' then move axis in the negative direction.
With the mode set to zero return I can not jog the axis (though the manual reads as though I should be able to to return to zero). If I change back to jog mode
I can jog manually but with no zero return indication.
Initially - do you have a manual which explains the Beaver specific EX codes at all? If so would you send me the code explanations as they are not in my handbook.
Have you any ideas about the zero return? Should it jog back to zero (x-530, z-660) manually and give me some indication when in zero return mode or am I missing something?
Any idea how to reset the T-word error / message?
I noted that you spent some time initially getting the program format correct for moving the turret - can you let me know what the t-word format is as I have tried all sorts of formats and just get a 'start reject' message when I press the cycle start button. I was thinking this may also be because I haven't managed to do a zero return yet....
I would very much appreciate any help or ideas to get me a bit further... I have resorted to cleaning the machine now to make forwards progress though looking at the photos of yours I have a long way to go !!! There have been a few 'maintenance additions' to the machine by the looks of things in the back but I get the feeling I am not far away from getting things working properly - just limited by my own lack of experience with these machines....
Thanks in anticipation....
cheers
Jeff
Post by: awemawson on February 19, 2019, 11:43:30 AM
My machine has no EX commands nor have I heard the term Pulco. Tool number have to be between 1 and 12 followed by a D term that defines which tool offset to use.
For turret operation on my machine it first has to pass over it's X and Z references (done by selecting the reference symbol on the mode switch and pressing AND HOLDING the appropriate jog button), and then the turret subsystem has to be initialised in MDI mode by executing an M80 command, followed when it has finished (takes 10 seconds) by "Tn" where 'n' is the currently presented tool. (Commands terminated by 'LF') The control won't do anything other than jog until this procedure is completed. Now your system may well be very different . . .
The problem is that your machine is the "20F" therefore has the Fanuc control, so very few of the commands will apply at low levels. Nor do I have any information on the Fanuc equipped machines.
Beaver fitted several different turrets to these machines, and the turrets were controlled by different servo systems. Mine uses Beaver made turret, and the Siemens AC servos, but controlled by a Baldor 'SMCC' card that is a stand alone CNC two axis controller subservient to the Siemens 820T. But I suspect that your system probably uses Fanuc AC servos controlling a Baruffaldi turret that Beaver bought in as a cost cutting exercise.
I suspect that apart from the mechanics of the machine and possibly the main spindle drive little is the same between our machines.
Can I suggest that you start a new thread logging your progress, and detail what units you have by way of controls and servos. Put up loads of pictures of the items and internal of the rear cabinets.
Post by: JeffK on February 19, 2019, 01:10:14 PM
plenty of pictures tomorrow to post in a separate thread.
I think that some of the issues I am having have been due to the axes being manually moved by turning the ballscrews with the power switched off on the machine.
This is resulting in errors in the pulse encoders and possibly preventing the zero return. Not sure how to fix this just now.
Anyway I will post a new thread and hopefully people can give me pointers.
I will continue to follow your thread with interest as I too hate to see good equipment scrapped just because it needs a bit of attention and time spent on it.
cheers
Jeff
Post by: awemawson on February 19, 2019, 01:58:09 PM
I can put you in touch with an ex-Beaver Engineer who undoubtedly can assist, but he is extremely good at writing invoices
I should warn you :bugeye:
You appreciate that Beaver went to the wall in the early 1990's so not many are about who know these machines, and as far as I can tell they only made something of the order of 250 of these lathes.
I look forward to seeing your new thread! (Can you please limit the picture size to 800 x 600 pixel to save on Eric's server space)
Post by: JeffK on February 19, 2019, 04:45:25 PM
I believe quite a few of the machines went for the export market so likely hard to find anyone in the know in the UK. In addition I am up north of Aberdeen so
even harder to get anyone to actually work on it....
cheers
Jeff
Post by: RodW on February 20, 2019, 08:17:53 AM
I kinda wondered part way through if it would have been possible and easier to retrofit it with LinuxCNC? Some of the hardware from Pico Systems and Mesa (which I use) might have provided a way forward without being constrained by lack of factory parts. And I also wondered if it would have produced a superior result? (Mainly becasue one day I might try and do that to an old machine).
It kinda nice to open up Google Drive in Chrome on your machine controller so you can download the cad files you want to process....
Post by: awemawson on February 20, 2019, 08:26:01 AM
The motivation was to get it back 'as was' and anyway there are some massively powerful servos and spindle drives on this beast that would cost a fortune to replace.
I know of a chap who has done what you propose to a Beaver TC10 the smaller younger brother of this machine, but it's not what I wanted to do.
Post by: RodW on February 20, 2019, 04:46:24 PM
Rod,
The motivation was to get it back 'as was'
Yeh, I got that and its a credit to you that you slavaged a machine and was able to restore all of the failed electronics
Rod,
and anyway there are some massively powerful servos and spindle drives on this beast that would cost a fortune to replace.
LinuxCNC should be able to control the existing motors on these kinds of machines. I certainly agree it would not be viable if you had to replace the motors.
So save that idea for when you buy the machining centre to go with the lathe. :headbang:
People so often think of the limited I/O parallel port breakout boards with home built CNC but with LinuxCNC and Mesa, this can be infinite plus support most of the control panel features and handle encoders and resolvers. There are different options for running servos but even the $200 Mesa ethernet connected 7i76e I use has 32 inputs, 16 outputs, 5 step generators, 4 analog inputs, 2 Mpg inputs, spindle encoder plus an option to add 2 more similar daughter cards before you venture into the onboard smart serial RS422 interface that allows you to daisy chain a whole host of other I/O options.
Post by: naffsharpe (Nathan) on February 21, 2019, 03:17:52 PM
Post by: awemawson on February 21, 2019, 06:04:08 PM
Post by: RodW on February 22, 2019, 04:25:58 AM
Its hard to get a good supply of corks these days. Far too much wine in screw tops down here! I think I better go and open one seeing its Friday night here...
Post by: awemawson on March 09, 2019, 01:05:50 PM
I turned an accurate 10 mm spigot on a bar end and left it in place in the chuck. Then on my manual lathe I drilled and bored and reamed an accurate 10 mm sleeve in a bit of brass hex. then with a 10 mm dowel pin mounted in a 10 mm end mill holder in tool position #1 offered the two together. If aligned properly the sleeve should slide from one to the other when the X axis is set to zero.
Well as expected it didn't - it was out in X as well as height - so a repeat of turret adjustment was called for.
It was my intention to sweep a DTI round the inside of a VDI 'tool hole' in the tool disk, but much to my surprise I found that the holes are intentionally not round :bang:
Post by: awemawson on March 09, 2019, 01:21:50 PM
Then there was a slight detour making a rigid DTI holder to go in the chuck and off I went tweaking turrets again!
But first I roughly marked the quadrant points on the 50 mm diameter, as judging them from the odd angles that you are forced to use isn't easy.
So repeat of the previous exercise and setting it went pretty easily, tapping the tool disk slightly to get an exact centre position. The X error as displayed at this point was -0.197 mm which can be corrected by applying a 'grid shift' by entering half the error in microns into a parameter - or so the procedure said :hammer:
I went all over the place, error increasing, error unchanged I was going scatty, until it dawned on me - the measurement and error correction values are being measured using a system that already has (wrong) compensation applied. Starting again having set the compensation to zero all went to plan in a matter of minutes. Of course in the factory they go onto the commissioning floor already with zero in the parameter so no need to mention it :bang:
So, remount the tools, reset all the tool offsets, remake the 10 mm spigot and try again. SPOT ON - the sleeve slides nicely from dowel to spigot when X=0 . . . . phew
Post by: nrml on March 09, 2019, 02:48:28 PM
Post by: awemawson on March 09, 2019, 03:40:20 PM
All very frustrating :( :scratch:
Post by: tom osselton on March 09, 2019, 03:43:56 PM
Post by: awemawson on March 09, 2019, 04:21:41 PM
I've posed the question on the Practical Machinist Forum so hopefully someone with more experience than I will give us the answer :med:
Post by: PekkaNF on March 10, 2019, 04:49:41 AM
* Round hole with loose fit shank would give a line contact, while that pin on the front or other feature indexes it and prevents it from turning there would be tendency to "rock" about that single line contact.
* On the other hand V-groove would give a two line contacts for a round counterpart----maybe this round pockect odd relief woud serve the same function in economical execution.
Never seen this construction, but if that serves other purpose I keep mine in mind...least I think it might come handy :)
Pekka
Post by: awemawson on March 12, 2019, 09:08:48 AM
Symptoms: Turret clamp solenoid not clamped. It EVENTUALLY turns out to be a simple bad connection on a Sub D 37 way connector used on the input array, this pin takes the 'clamp request' from the SMCC subsystem conveying it to the controller that should then act on it, clamping the turret.
Along the way I've had to replace the vastly expensive Euchner 'unclamped' switch as it couldn't reliably be set - this thing works on 10 thou movement to switch!) - fortunately I'd had issues with it before and had bought a 'pre-emptive spare'. And I've discovered that certain cables are incorrectly marked differently at each end, with wires for 'clamp' and 'unclamp' being interchanged in a couple of places, but 'end to end' the errors compensate and it works in the correct sense !
So the thing that the fault is on is a Klippon 068386 terminal block. It probably only has a dry joint on it's pcb but although I'd hoped to solder the pin in situ - it's all enclosed. Only ebay one is in the US and although reasonably priced the postage is ridiculous.
I've wiggled the connector into a working position, and the machine is running as I type this, but of course it needs fixing. If I can't source a spare I'll pull this one apart - bit of a pain as it has about 40 cables screwed into it !
Post by: redshift on March 12, 2019, 01:33:36 PM
Regards, Dave
Post by: awemawson on March 12, 2019, 01:50:30 PM
Post by: redshift on March 12, 2019, 02:20:52 PM
Post by: awemawson on March 13, 2019, 10:40:32 AM
By the time I got half way through the process I thought, blow this, leave the wires off and see if you can attack the Klippon block with a soldering iron. Someone on another forum had told me that the orange plastic of the blocks is in two parts, the sides clipping together, and if unclipped the PCB is released.
So, all wires off, and released from the DIN rail, sure enough with a bit of persuasion the sides came off letting me see the solder side of the PCB for the first time. To my amazement every single pin of the 37 way Sub D connector had a neat little skirt of solder about 1/2 mm off the board - the whole lot were dry joints :bugeye: So the 'solder to pin' junction had stood the test of time, but the 'solder to PCB' junction had failed. I assume that these were flow soldered originally - perhaps the PCB cleaning wasn't up to scratch :scratch: (But the joints for the terminal blocks were fine)
Careful application of a bit of flux along with flux cored solder and soldering iron, and I remade all the joints. All passed a continuity test so I re-assembled the block, re-wired it in the machine and crossed my fingers.
All was well, she fired up like a champ and passed the tap test ("Tap with screwdriver handle in the manner of a reasonable man")
It does beg the question what is the state of the other four of these blocks - but then, I'll have a spare arriving next week :clap:
This exercise did at least give me an excuse to try my new Chinese "Heat Proof Silicone Soldering Mat", and I must say it's actually pretty good - saves my desktop drawing surface, and is thick and pliable enough to stop things skidding about as you work on them.
Post by: nrml on March 13, 2019, 05:39:58 PM
Post by: russ57 on March 14, 2019, 02:39:25 AM
Russ
Post by: awemawson on March 14, 2019, 03:12:08 AM
The DIN rail that they mount on is right at the top of the cabinet, and the connected wires are too short to get the unit off while still attached.
However I do intend to work my way through them starting with the extreme left one this morning. Some are quite sparsely wired so should be easy, but #5 at the extreme right is fully populated so will be time consuming.
Russ: not seen the B&Q mats so can't comment. This was £11 inc postage.
Post by: awemawson on March 14, 2019, 06:13:01 AM
It took two hours end to end and thankfully all tested OK on re-assembly. Oddly there was a link on pin 16 but the PCB track looked OK and tested OK. The soldered joints didn't look too bad but I re-did them anyway and also left the mystery link in place - maybe the track has a hairline crack?
Can I face doing another one just now - mm - have a coffee and a think :coffee: :coffee:
Post by: hermetic on March 14, 2019, 07:55:44 AM
Phil
Post by: hermetic on March 14, 2019, 08:21:01 AM
Post by: awemawson on March 14, 2019, 08:24:17 AM
Only one pin that looked possibly suspect, but of course I re-soldered them all. This one was a bit of a pain to do as several terminals had multiple cables entering them. There was the "bugger" moment when re-wiring it I found that I had two white wires BOTH labelled #30. I remember now that that was when the Postman arrived :bang: Easily sorted with the circuit diagram and a meter. Cable #29 now CORRECTLY labelled :thumbup:
Then there was the heart stopping moment when testing and the machine refused to jog. Looking for a wiring error I found I'd left the 37 pin cable unplugged - plonker :clap:
Tested OK eventually - so that's three out of five done. Depending on how good lunch is I'll try for another later !
Post by: awemawson on March 14, 2019, 10:49:47 AM
All went well, the soldered pins looked absolutely fine, but of course I soldered them anyway. Re-assembled it - re-wired it and all tested OK - phew !
. . . on to the next (LAST :thumbup:) one before I crack !
Post by: awemawson on March 14, 2019, 12:08:43 PM
The last one, OP2, wasn't too bad. Although pretty well fully populated all but eight wires had sensible numbers on them. Once out an inspection showed that one pin was a bit suspect at the extreme end of the socket, but of course I soldered all 37 then tested them for continuity. All well when re-installed :thumbup:
So hopefully that has shaken out a few failures down the road and improved reliability markedly. It was only the IP3 block that show a gross error with virtually every pin moved off the board. Strange really as the cables to the D37 sockets are all well secured to the cabinet and not apparently straining the connector :scratch:
Post by: seadog on March 14, 2019, 12:44:14 PM
Post by: awemawson on March 14, 2019, 01:38:59 PM
Decades ago (late 1960's) I was involved making multi-element infra-red arrays for use in spy satellites. Everything went though full spectrum vibration testing and you'd be amazed what that can do to apparently rigid structures!
Post by: Will_D on March 15, 2019, 07:57:07 PM
And yes they actually recorded the telemetry from a truck driving on roads all over the UK o run on the shaker table.
Post by: awemawson on March 27, 2019, 06:42:22 AM
No, still no word about the bits that have "gone walk about" in Australia, but an MP12 brand new probe appeared on eBay that was well out of my price bracket, but the seller had mentioned that he had tested it as working. Now as I had obtained an MP12 in a job lot of bits earlier in the year I fired off a message asking him how he was testing it, as I have no idea if mine works or not.
Turns out that he had a spare OMM (that's the receiver bit that stays fixed to the machine) - mines being kicked about by Kangaroos in the Antipodes :bang:
Discussion ensued and the grand chap let me have it at a very reasonable - far too reasonable - price and not only that let me have an OMI version which is the same as the OMM but includes the electronics of the machine interface.
To cut a long story short, the postman brought me a box this morning with the Renishaw OMM & OMI - I need to curtail my excitement as we have guests for lunch and are out tonight so I wont be able to try things until Thursday.
My MP12 doesn't look too bad, but when I got it, the AA batteries had been left in and had corroded so took some extracting - I hope that the vapours haven't travelled into the electronics. But I do also have an LT02S optical probe in unknown state so quite a bit of experimentation is needed to find what does and what doesn't work.
Renishaw have used several signalling systems for their optical probes, including different IR wavelengths to allow more than one probe system to co-exist in the same machine, so I hope I have a compatible set up - time only will tell !
I am delighted to say that Cliff, the eBay seller has joined us here on the forum as 'Brent Crude' - he is a star and my current hero - thank you Cliff :bow:
Post by: tom osselton on March 27, 2019, 02:24:50 PM
Post by: kayzed1 on March 27, 2019, 08:00:26 PM
Post by: awemawson on March 28, 2019, 06:33:49 AM
Connecting the OMI receiver unit to a bench supply and using it to try and trigger the MP12 probe, freshly equipped with new batteries - zilch, the MP12 doesn't 'wake up' so the OMI displays ERROR on time out as it never receives a reply from the MP12.
Getting out the LT02S optical transmitter with it's LT2 sensor module - (both these functions are contained within the MP12) we have lift off :clap:
The two happily talk to each other over quite a range and quite an angle of incidence, and 'probe triggered' status is displayed by the LED on the OMI at the appropriate time.
So in all the months that I've been working on this lathe this is the first time I've had an optical probe doing sensible things and working.
I conclude that the MP12 probe is either doing an excellent impression of a door nail, or is using one of Renishaw's alternative signalling schemes.
Now the original set up was a Renishaw MI12 machine interface sitting between an OMM receiver unit and the Siemens 820T, but as I understand it, the OMI version incorporates the MI12 function within itself thus making the MI12 redundant.
I will initially test the OMM that Cliff sent me and if it talks to the LT02S just install it 'as was' to simplify the wiring, but either way now I know that I have a working system at last.
Post by: awemawson on March 28, 2019, 07:51:05 AM
The OMM has a different 'start signal' requirement so I can't easily lash it up on the bench. The MI12 generates a one second burst of 125 uSec pulses at 250 mSec intervals, which are passed to the OMM, which transfers them into IR to turn on the probe. So the easiest way to do a test was to lash the OMM from Cliff into the machine on the wires where the original OMM had been.
When I removed the original to send to PK in Australia, I had double bagged and Ty-Wrapped the cable ends to keep out swarf and coolant. Removing the bagging amazingly all was well inside and I was able to connect the replacement OMM, using it's already attached cable and 'chocolate block' connectors leaving the OMM on the 'operators shelf' by the Siemens control.
I'm delighted to report that all was well, and a probe trigger would cause the 'probe status' light on the MI12 to change state and on the Siemens control 'Flag Byte 24 bit #7' also changed state - a result :clap:
This is quite a relief as it's the first time I've been able to definitely prove that the MI12 machine interface is working. Back in the early days when I got the machine, one of the two paralleled up 24 volt power supplies had had a failed 2N3055 transistor dragging the volts up to (iirc) something like 36 volts whereas the absolute maximum spec on the voltage for the MI12 is 33 volts so to find that it IS working is good news.
So altogether a very good day so far. Cliff, there is a pint or two of Harvey's Best Bitter waiting for you when ever you venture down this way - such a relief to at last get close to having an installed work piece probing system set up. Setting G54 off sets with a ruler is far from ideal :lol:
:beer: :beer: :beer: :beer: :beer: :beer:
Post by: awemawson on March 28, 2019, 11:27:57 AM
It's a very awkward location to make off cables - the entry into the OMM body will barely take the sheath of the cable and certainly no room for 'boot lace ferules' which make making off fine wires so much easier. I ended up tinning the bare ends of the individual wires, this isn't good practise as strands can break under vibration where the solder ends, but there wasn't much choice.
All back together I then mounted up the probe in a VDI40 boring bar holder ready for testing. This makes a very long 'tool' so I will probably make a custom holder that can be shorter. The concentricity of the probe with the VDI40 mounting socket is set by adjusting four tiny Allan socket grub screws - I've not attempted that as hopefully soon it will be mounted on a different holder.
A trial test jogging the odd micron at a time showed me that it was working by monitoring the Flagword 24 bit #7 location, so I suppose now I need to get my head around writing some code to handle the probe. I may try and incorporate it in the PLC if there is still room, as that way I can put the brakes on the travel in all cases even when other programs are running as a safety precaution.
Post by: Brent Crude on March 29, 2019, 02:12:40 AM
Quite a project you have there!
:beer: :headbang:
Post by: awemawson on March 29, 2019, 03:27:28 AM
Up early to put in yet another call to Australia to chase the original bits, according to a colleague they are still in a tote on PK's desk (who was off picking children up from school). There is now a large entry on his 'white board to do list' asking if I can please have my bits back :bang:
So while I was up I thought that I'd have another go at the MP12. It takes four AA cells, retained by a cover that also does the inter-cell bridging, with the 6 volts being picked up by a pair of spring loaded gold pins. Rigging up the lab power supply with croc clips on the pins, with my trusty Avo 8 in series showed me that when first connected there was an initial surge of perhaps 10 mA, very rapidly falling back to about 1 mA or less. However if I pointed my remote control for my 100 W led flood light at it, and gave it some random IR it would switch into a higher current mode - maybe 5 mA.
Re-installing the four AA batteries and exposing it to the OMM in the lathe there was still no response. Frustratingly like this I couldn't monitor its current draw.
However I conclude that the MP12 is at least partially alive, and can be switched into operating mode by a burst of IR. Still possible that it's signalling specification differs from the OMM.
I may try and make up some sort of replacement battery cover that lets me use a lab supply and monitor current while on the machine exposed to the OMM. This way I can get a better idea if the OMM is actually switching it from standby to the on state.
Post by: Brent Crude on March 29, 2019, 03:15:06 PM
Post by: awemawson on March 29, 2019, 06:12:30 PM
Do you know what the white LED that emerges downwards through the bit of the top that is not the battery retainer is supposed to indicate ? Perhaps 'probe triggered' status ?
*** later edit, I've found a datasheet implying that it's a switch that changes the probe mode - doesn't look like a switch to me ! ***
Post by: Brent Crude on March 29, 2019, 09:19:26 PM
Post by: awemawson on March 30, 2019, 03:40:49 AM
Post by: awemawson on March 30, 2019, 04:43:27 AM
(Cliff I've sent you a PM)
Post by: Brent Crude on March 30, 2019, 06:54:39 AM
Post by: awemawson on March 30, 2019, 07:00:55 AM
That LED is the one that flashes green when the probe is on and red when it is triggered.
Or in my case coyly stays off keeping it's own council :lol:
Post by: awemawson on March 30, 2019, 01:03:40 PM
All went well I'm pleased to say - phew
(The Z co-ordinate is loaded into register R1)
Post by: tom osselton on March 30, 2019, 03:06:11 PM
Post by: awemawson on March 30, 2019, 03:15:59 PM
It doesn't help either that the two probes are numbered 0 & 1 in one function (@371) and 1 & 2 in another (@720) - nothing like having a bit of consistency :clap:
Post by: awemawson on May 05, 2019, 10:10:24 AM
Apart from the time to do it the hold up has been deciding how to make the actual VDI40 spigot that has the rack teeth that engage with the locking mechanism. I know from when I 3D printed some blanking plugs that the 'phasing' of the teeth is quite critical.
Having worked out a way, an odd shaped VDI tool that looked like it could be a 'doner' cropped up on ebay which I won for the princely sum of £4. I had expected to have to soften it by annealing before I could work on it, but it turns out it is a custom made item using a commercial 'soft blank' where the VDI40 bit is hard, but the rest is still soft(ish). Well that saved digging out the annealing furnace :thumbup:
So today I found a bit of time to make a start. The blank is far too long so how to lop a bit off - looking at it I reckoned probably at least two parting tool tips were it done on the lathe, so I used the Band saw with a bit of ingenuity in the clamping - went quite well and wasn't all that slow considering it's 85 mm in diameter.
We need a spigot of 44 mm o/d 16 mm long with a projection of 25 mm 4.5 mm long, all bored out to 20 mm for a depth of 36 mm. Renishaw helpfully give an un-dimensioned drawing but I have an SK40 shank to copy - so that's OK
Post by: awemawson on May 05, 2019, 10:22:23 AM
I thought as the three jaw was already mounted I'd pop it in it and see how perpendicular the band saw cut was. Answer: amazingly good :clap: And even MORE amazing just spinning it by hand the shank LOOKED pretty concentric (I'd wrapped it in brass shim to protect it from the jaws). Putting a DTI on and revolving by hand it was SPOT ON :ddb:
So I continued with it in the three jaw and rough turned the two diameters oversize by 2 mm and drilled the 20 mm bore undersize at 18 mm. I'll let it all cool down before the finish machining while I feed the pigs.
Post by: awemawson on May 05, 2019, 12:29:02 PM
The two outer diameters were taken down to size, and the bore bored out to 20 mm . Then I mounted it in the milling machine and drilled and tapped the two 8 mm cross threads for the retaining grub screws.
The way it works, is that there are four tiny allen grub screws on the probe body that bear on the smaller outer diameter of the adaptor, and by tweaking them concentricity can (hopefully) be achieved. Then the two 8 mm pointed grub screws in the body of the adaptor bear on a conical washer loosely retained on the rear on the probe body. These screws and conical washers tightly hold the probe body in contact with the adaptor yet allow adjustment.
So that's one more 'round tuit' put to bed :ddb:
Post by: Brent Crude on May 06, 2019, 01:23:36 PM
Post by: awemawson on May 06, 2019, 01:48:30 PM
The MP12 is intended for the vertical spindle of a milling machine of course.
All is not lost, as the probe mounting is universal to a few Renishaw probes, and I have another (an LT02S) that has the window pointing in the right direction !
Post by: awemawson on May 07, 2019, 06:34:47 AM
I've handled these things numerous times but the fundamental difference never dawned on me.
Oh well, honour redeemed by mounting the LT02s on yesterdays adaptor and I've proved that it works as fitted.
Post by: tom osselton on May 07, 2019, 04:26:53 PM
Post by: awemawson on May 07, 2019, 04:37:23 PM
Theoretically I could have moved my OMM to the roof of the enclosure but in practice the sliding door curves up there and stops that being a solution.
Post by: tom osselton on May 07, 2019, 05:19:30 PM
Post by: JHovel on May 09, 2019, 11:42:30 AM
Could you use a mirror to redirect the IR signal back to your sensor? While probing, I imagine there would be no coolant interfering with the mirror. Perhaps mounted high in the enclosure (even near the top of the door) might just work....
Cheers,
Joe
Post by: awemawson on May 09, 2019, 12:41:37 PM
Today I started gluing up a wooden box to house the LT02S probe and holder, and 3D printed a cover for the ruby probe itself. Hopefully tomorrow the PVA will be set enough to finish it off and fit catches and hinges. I used the offcut of the 12 mm ply that I got for the counter top of the Versatool cabinet. What horrible stuff modern plywood is - looking at the cut edges it was full of voids.
Post by: awemawson on May 10, 2019, 10:00:16 AM
Eventually I settled on my 100 mm magnifying glass that sits at my desk - it has the advantage that the glass is pretty thick.
End result is that the probe is quite happy to function both sending and receiving through the glass, so I've splashed out and bought some small prisms on eBay. Coming by slow boat from China so not expected until the end of the month. To get the size right I need to mount two 10 mm x 10 mm x 10 mm next to each other so a bit of fiddling required.
I seem to recall that there is a special optical glue used for lenses in contact, but actually I don't suppose it'll matter in this case that half the signals go through one prism and the other half through the second one :scratch:
Post by: charadam on May 10, 2019, 11:24:16 AM
Post by: awemawson on May 10, 2019, 11:42:14 AM
Not to be confused with Friars Balsam :clap:
Post by: nrml on May 10, 2019, 05:32:18 PM
Post by: awemawson on May 16, 2019, 09:39:05 AM
First I made a closed box, pinned and glued which was left for the PVA to set hard. Then the closed box was sanded down to a fair finish which revealed the rubbish quality of the "12 mm 7 ply" that I was using. It turns out that actually it's 9 ply, with the extra two plys being paper thin and effectively just colouring at 5.5 thou thick! Bits got sanded off which proved to be very difficult to disguise with the stained varnish that I used.
Then the box was sawn into a top and a bottom, thus ensuring that they matched in 'unsquareness' though in fact they were pretty good.
Umpteen coats of dark oak varnish stain later I was able to fit the hinges and corner protectors. With water based and oil based paints I always suspend my brush in water to prevent it drying out over night, as it easily shakes / wipes dry ready for the next coat. Saves ages washing brushes :ddb:
Post by: awemawson on May 16, 2019, 09:42:06 AM
Some time earlier I had 3D printed a protective cap in ABS that slips over the actual probe itself, preserving the ruby tip (hopefully!)
Post by: awemawson on May 26, 2019, 10:13:39 AM
I had always intended to re-locate the batteries (as there are two) to a place where were they to leak again no damage would be done, and to this end I had obtained a spare battery holder like the existing one so that rather than have a large button cell on a card and a C size cell in a holder, there would be two C sized holders remotely wired.
The problem was that the original rather over complicated battery holders were a pain to mount in an appropriate place low down so that leakages would be less of an issue. But then it dawned on me, If I used a pair of conventional panel mount cylindrical C cell holders, and put them in a plastic box such that it would contain leakage then where it was mounted became far less critical.
So an acrylic box and a pair of Bulgin battery holders were ordered from RSComponents and assembled.
First picture is of the original RAM card that was totally destroyed by the battery leak
Post by: hermetic on May 26, 2019, 10:27:26 AM
Phil
Post by: awemawson on May 26, 2019, 10:27:59 AM
Removing the "Button Cell" was easy enough, but then I had to attach a flying lead running to the new box while providing cable restraint and yet still be able to use the card extractor cover with which it is fitted. I say button cell, it's nearly the size of a beef burger ! I then used it's two negative plated through holes to mount a 'goal post' of stiff copper wire to act as a cable restraint, passing the wire through a hole that I drilled in the extractor cover.
Post by: awemawson on May 26, 2019, 10:33:39 AM
I decided to solder wires to my spare battery tray, leaving the other wiring undisturbed, and in doing so revealed a totally undocumented fuse wired in series with the battery. My modification keeps this fuse still in circuit
Post by: awemawson on May 26, 2019, 10:44:59 AM
Usual thing - drawn in Autocad, exported to SheetCAM, plasma cut on the CNC Plasma Table by Mach3 and given a zinc rich primer and matt black top coat. Drilling it's mounting holes was 'interesting' from within the small space, but I had installed hank bushes in the shelf, so screws could be accessed from above and outside the enclosure.
It was then a case of plugging it all together, doing (hopefully) one last re-load and testing that the machine still works (which it does).
Now, with the power on, I can remove either or both of the batteries and replace them, and if I need to totally withdraw the controller, the battery box can remain connected, and come with it still retaining RAM
The shelf has a front lip upstand to prevent the box ratting off, yet allowing it to be tilted for planned removal
Post by: awemawson on May 26, 2019, 10:51:46 AM
Very neat Andrew! Could you not (if needed) put another battery holder in parralell, or switched in, so that you could fit a new battery before removing the old one, or have you engineered out that memory volatility now?
Phil
Phil,
The original (Beaver) design precludes that, as you can't actually get at the batteries, but with my new layout I can easily get at them while the power is ON thus RAM data is retained.
Post by: RussellT on May 28, 2019, 04:43:55 AM
Your problems with sticky backed baize reminded me of a technique I have used effectively a few times. I discovered this when attaching golf club grips to a dinghy tiller extension. Golfers use double sided carpet tape and stick that to the club and then wet the grip and tape with white spirit and that makes the glue really slippery so the grip just slides on. I have adapted this when trying to position sticky backed tape inside the dinghy centreboard case. Wetting it with white spirit makes it easy to slide into position. I wonder whether this would work with the sticky backed baize.
Russell
Post by: awemawson on May 28, 2019, 09:54:29 AM
Objective was to replace the retro-fitted Renishaw OMM / MI12 / Siemens 820T wiring, as it had been draped on the floor and not run in the conduit. And at the same time wire the MI12 interface box via plugs and sockets to make it removable.
Back in November I'd made up a box, fitted it and wired three XLR panel mount plugs / sockets, and laid the multi-way cable in trunking or Adaptaflex as appropriate, and got the OMM cable as far as an adaptable box on the end of some flexy conduit awaiting the return of the OMM from PK. In the mean time my bacon was saved by another member (thanks Cliff) who was able to let me have a replacement OMM to get me back on track.
Firstly I made up three 'umbilical cords for the MI12 interface (To OMM socket, To 820T controller Socket, and To 24v socket)
Then I fitted shoulderless boot lace ferrules to the OMM cable that I'd coiled in the adaptable box, and dismantled the OMM from the bulkhead and re-wired it using the new cable, with the conduit nut retaining the box on the bulkhead. Why shoulderless? The ones with shoulders won't fit through the OMM entry hole !
Post by: awemawson on May 28, 2019, 10:04:11 AM
Fingers crossed and power was put on and both probes tested and thankfully worked fine - they should of course as it's only a simple wiring replacement, but you never quite know what you are going to disturb in the process.
Once I was happy all was working it was just a case of carefully removing the original cables, again without disturbing anything else, or tearing them to shreds on the bare holes without grommets that they'd been threaded through :bugeye:
Post by: awemawson on May 29, 2019, 06:58:40 AM
It's been loose since the day the machine arrived and I pulled the control forwards for investigation - that was 12th May 2018.
I've seen countless pictures on the Interweb of these controllers with broken front panels and I'm not at all surprised. They are plastic and if you are not at all careful removing and installing puts far too much strain on the fixing flange which promptly breaks off. I was lucky - there was only one corner broken on mine from the Operator Panel, and the broken bit was still there and able to be re-glued. But the corners are incredibly vulnerable until all screws are bearing the weight. I think it is probably sensible should future removal be needed to remove all corner screws first, then the others.
When I was removing it on the day it arrived, unbeknown to me there was a hidden floating captive nut bar that greatly confused me getting the controller out despite the fact that all it's screws had been removed - easy when you know !
So, 820T screwed back in (14 screws and two bolts in the captive nut bar), Operator Panel back in (10 screws - careful of that glued corner!)
Now another dismantling puzzle had been how the end access panel was retained - answer inwards projecting welded on studs with brass inserted Bakelite knurled hand screws thoroughly stuck and requiring the use of pliers to unscrew at an unbelievably difficult angle for my hand - I seem to remember dropping at least one set into the machine that day. So when they went back on, each stud had a dab of 'Copperslip' hopefully to prevent such things in the future and allow hand unscrewing. I suspect this issue was made worse by the fumes from the lithium battery when it had died.
Then the filter retainer and filter and the machine is completely back together :ddb: :ddb:
Now I can play with it without feeling guilty that there is still outstanding work to do :thumbup:
Post by: awemawson on June 04, 2019, 09:44:14 AM
Remove the hard jaws from the chuck, mount up a set of three soft jaws and bore them for gripping 25 mm - how hard can it be :scratch:
It certainly started off well. Clamp the spindle to give something to torque against, out with the big allen key and unbolt the hard jaws. Stamp up the new soft jaws so we know what goes where in the future and fit them.
This is where it started to go down hill - the new jaws are too long to fit without overhanging the outer circumference and only using one retaining bolt - and this I was NOT prepared to do.
Looks like I'll have to start profiling them in the milling machine and finish bore them on the lathe - a bit of a pain
Post by: awemawson on June 04, 2019, 09:53:06 AM
Now with the 20 mm initial bore that dictated the largest diameter end mill that I could use (19 mm) and as these jaws are 50 mm deep and pretty tough I was somewhat concerned with endmill flex.
I wound the feeds back considerably from FeatureCAM's defaults but try as I may I could not eliminate horrible chatter within the 20 mm bore. In retrospect I think it was that the chips only had a narrow gap to escape, but in the end it really didn't matter as it was going to be finish bored on the lathe
Post by: awemawson on June 04, 2019, 10:11:43 AM
So what to do :scratch: I could make something up for this one size, but this is going to be an ongoing requirement as jaws are changed in the future. Better to bite the bullet and get the right thing. A bit of ringing around for best price set the dealers into a flutter, as behind the scene it turns out that they were ringing each other to see who had stock. Rotagrip won the day, and then minutes after I placed the order Cromwell Tools rang me back to say that their supplier had just sold their last one, and they were now on 8 weeks delivery. Yes says I, I just bought it :lol:
Excellent next day delivery, so the clamp ring arrived this morning by Adrian with ParcelForce.
Now the theory is that you adjust the ring to such a size that the hydraulic chuck jaws bear down on it via pegs that go into the counter bores for the jaw mounting screws and it ends up clamped with a bit of 'meat' for you to bore out with a boring bar. It's actually quite a job juggling it, holding it in place, and operating the 'chuck close' button that is a fair distance away from the chuck.
It was at this stage I found that as these were new jaws and still fairly long, the clamping ring at its extreme would not clamp :bang:
A bit of head scratching showed that as the clamp pegs are 18.5 mm and the chuck jaw counterbores are 25 mm, the slack was the problem. Quick solution, turn up some collars to slip over the pegs and sure enough we now have the correct travel to clamp, but we also have a pile of bits to hold in place at once while pressing that button, arm outstretched. Flying to my aid came some rare earth magnets, that not only held the collars on, but nicely held the clamp ring against the chuck jaws :clap:
Post by: awemawson on June 04, 2019, 10:30:26 AM
I'd turned up a plug gauge on the manual lathe with 24.5 and 25 mm diameters, as this boring was going to have to be done the old fashioned way - cut - measure - cut again. (The boring bar hasn't been measured and put in the tool offset table yet!)
So, cut a bit, measure, cut again measure with the bore gauge, get a finish depth of cut a whip it off. I used the jog facility and MPG rather than a program as the tool disk gets rather close to the chuck jaws as I wanted to minimise tool overhang.
. . . so what should have taken a couple of hours took a couple of days !
Post by: awemawson on June 11, 2019, 06:48:38 AM
I did an experiment with transmission through glass that proved that the IR wavelength used would pass, so ordered some prisms off eBay that have been on a slow boat from China, hoping to turn the beam through 90 degrees.
Well the boat has docked at last and would actually appear to have come from Malaysia. I had ordered four prisms, knowing that two would when joined cover the width of the optical window in the probe, and the others could be spares. Just as well, as two of them were chipped. Frankly unlikely to affect the passage of the IR much, just unsightly.
So experimenting with the two chipped ones - not worth sending them back at the price they were(n't) - I super-glued them together with the smallest drop that I could decant, then fixed them temporarily to the MP12 with a tiny dab of hot melt glue that will be easy to remove without damage to the probe.
Lo and behold - they WORK :clap: Now I just need to devise a more robust method of retaining them on the MP12 probe that looks less crude than the experimental set up - but definitely a success :thumbup:
Post by: nrml on June 11, 2019, 08:47:55 AM
Post by: AdeV on June 11, 2019, 12:39:07 PM
Lo and behold - they WORK :clap: Now I just need to devise a more robust method of retaining them on the MP12 probe that looks less crude than the experimental set up - but definitely a success :thumbup:
Something vacuum formed, perhaps? :D
Post by: awemawson on June 12, 2019, 09:23:00 AM
Most commercial CNC lathes would have foot pedals to open and close the chuck so why not retro-fit some :ddb:
I went hunting for spare digital inputs and some way of intercepting the drive to the 'open' and 'close' solenoids and drew up a simple schematic - it didn't even need any alterations to the PLC.
So, going to the termination strip for my selected input I was very surprised to find a wire already attached - it wasn't spare after all :bang: So, attaching my 'tone tracer' to the wire I traced it all the way to the front hydraulic cabinet under the headstock and thence on to a socket on the side of the box that I'd never before noticed. Now this socket also has a double below it, and they are JUST where I would have put sockets for foot pedals . . . you don't suppose . . . no surely not . . . YES looking through the PLC code and relating it to the wiring diagram they are for foot pedals for the chuck and for the tailstock - whoopee :clap: :clap:
Looking at the PLC code they both act on an already energised item - so if the tailstock barrel is pushed forward the foot switch will withdraw it until you take your foot off, where in it returns extended. Similarly a closed chuck will start to slowly open when your foot is depressed, and start closing when you take your foot off. EXCELLENT :clap:
So I ordered up the appropriate connectors and a pair of sturdy foot switches and the later arrived at lunch time. OK cable them up and test them !
The foot switches are I think excellent value - cast aluminium with a proper heavy duty micro-switch. My only criticism of them is the cable management. The entry was a plain bush and a flimsy bent metal 'C' shaped clamp, but easily replaced by a proper cable restraint gland, and it's not so easy to route the cables so that they are not flexed each time the pedal is pressed, but it is possible.
OK Wired up, plugged in and tested - all works :thumbup:
Post by: awemawson on July 03, 2019, 05:28:24 AM
So I decided to print up three 'Pucks' on my 3D printer with an o/d of a tad under the 66 mm spindle bore, an i/d of a tad over 25 mm for the stock, with counter bores to receive two spacers made from domestic ABS waste water pipe. As the pucks were printed in ABS this made the gluing together simpler as I could just paint the bits with acetone.
I designed the puck with an outer groove to receive an 'O Ring' to give a bit of friction to discourage 'walk out' and hopefully prevent it rattling too much. Not having the correct O rings I glued some up using O ring cord.
In the event the cord was a bit too fat and prevented the pucks entering the spindle bore so I will order up some slimmer ones, but in the mean time I did a full speed test working up from 500 rpm to 3500 and in practice there wasn't a 'walk out' tendency, but I shall still fit those smaller O rings when they arrive.
One side benefit was the ease of inserting a 4 foot long bar that was already aligned by the pucks to side between the chuck jaws :thumbup:
Post by: awemawson on July 20, 2019, 03:31:54 PM
Bar pullers are useful on a CNC lathe if doing repetitive work, in that you can automate the feed of the bar stock in the chuck between components. Advance the gripper over the bar, close it, grab the bar, release the chuck grip, pull bar out the length of the next component, close the chuck, release the gripper - all so nice and easy as it's automated :thumbup:
Now this gripper sadly had one of it's hard steel 'talons' missing - never mind - spares still available for the not inconsiderable cost of £99 (inc postage and VAT) for a set of three - BUT you get the fixing screws AND an Allen key, so a bargain :bang:
Biting my lip and remembering that these grippers cost £1400 new I shelled out my dosh and got the three spares.
Now I have a repetition job of 100 parts to do for a friend of a friend so time to mount it and play with some code. The gripper has a cylinder inside that can be operated by compressed air or coolant. No air service on this lathe so coolant it is. The sequence is, select the gripper, put it where you want it, turn the coolant on, do the pulling bit, then turn the coolant off again to release its grip.
Well, gripping works famously, but when the coolant is turned off it doesn't release. As the coolant is solenoid valve driven to the tool turret, coolant pressure is maintained in the line keeping the gripper firmly shut :bang:
OK a modification is called for. Another solenoid valve working in anti-phase with the feed valve dumping pressure in the line to the sump. It would have been VERY easy if I could have sourced a 24 volt DC 1/2" BSP brass valve in a normally open configuration at a sensible price, but they are rare with the proper industrial ISO plug in connectors.
Never mind, use a normally closed valve, add a couple of lines to the PLC program to add another output for this valve in anti-phase to the feed valve and the job's a good 'un :thumbup:
So valve and a few bits of plumbing have been ordered, and today I tweaked and tested the changes to the PLC program and now I'm just waiting for the bits to arrive .
Post by: AdeV on July 21, 2019, 05:23:24 AM
Obviously, you have to make one for every size of bar you want to pull; and it's no good if you need to pull something that's not plain bar; but it struck me as an elegant solution to the problem: Simple, cheap and reliable.
On the other hand... those grippers look cool! :thumbup:
Post by: awemawson on July 21, 2019, 06:48:39 AM
There are parting tool holders that incorporate a push fit forked gripper that grabs the bar by pushing in the X direction rather than Z - their concept is quite clever in that usually you want to bar pull after parting off so this avoids an extra tool change and associated move to a safe place, but like your tube the range of sizes is severely limited.
Post by: awemawson on July 22, 2019, 08:24:51 AM
I even bored a hole in the lid of the coolant tank to take the output hose from the currently non existent de-pressurising solenoid valve.
. . . . . so back to thumb twiddling . . . . .I don't do the patience thing very well :lol:
Post by: awemawson on July 26, 2019, 10:11:20 AM
As intended, the pressure is released from the coolant hose allowing the Grippex bar puller to release. Having this valve has the side benefit that the selected tool doesn't spray coolant for quite so long when the coolant is turned off. As the last operation is usually parting off, and the parting tool has a habit of spraying you with coolant previously left pressurised in the line, this is a GOOD THING :thumbup:
This video shows the new valve working as several tool changes and turning operations are performed. So now all sorted apart from a weep from one of the hose barb fittings that I must sort out. Probably just needs a new Jubliee Clip.
Post by: Johnny Bravo on July 28, 2019, 11:46:10 AM
Think I might be following your footsteps on this,have been offered a lathe with live tooling that could do with some tlc....Going to have a look in the week
Post by: awemawson on July 29, 2019, 09:51:58 AM
While I was at it I solved that slight coolant weep at the hose barb fitting with a turn of thick gas rated PTFE tape.
Post by: Sea.dog on July 29, 2019, 12:36:10 PM
A neat solution.
Post by: awemawson on August 15, 2019, 05:09:44 PM
It was a very useful leaning exercise, using the bar puller, and involved boring more soft jaws. Although 'spot on' soft jaws are still available they cost an absolute fortune. I was lucky enough to pick up eleven used sets on eBay that had the correct 1/16" by 90 degree serrations, but had M12 fixings on a closer spacing than the M16 originals, so this involved making stepped Tee Nuts to suit and re-machining the noses on the CNC mill to remove the existing curves prior to boring.
I also had to make a custom spindle liner
The exercise has made me think that a 'Tumbler' of some sort would be a useful addition to the workshop to de-burr parts like these that are very fiddly to do by hand. Has anyone built one?
Post by: hermetic on August 16, 2019, 01:08:01 PM
Post by: PekkaNF on August 16, 2019, 04:12:25 PM
Brother has one of these:
https://www.amazon.com/Lyman-1200-Sifter-Promo-Model/dp/B0063GS1Y2/ref=sr_1_1?keywords=Lyman+Pro+1200+Tumbler+%28230-Volt%29&qid=1565985760&s=gateway&sr=8-1
Bought this type (230V with proper Schuko), it is rather small, but works for me.
https://www.academy.com/shop/pdp/frankford-arsenal-quick-n-ez-case-tumbler
There is also a rotary type where stainless steel pins are used. Those tend to be bigger, more expensive and proper canditates for build.
Tumbler is the easy part. Took a while to find a supplier for 5 + 5 kg of abrassive media. One for deburring (plastic loaded pyramids) and one for satining (small ceramic cylinders) and some tubling "oil".
Pekka
Post by: mc on August 16, 2019, 04:19:21 PM
I made sure buy the media elsewhere though, as Frost was really expensive for it compared to the industrial suppliers.
Post by: awemawson on December 16, 2019, 11:35:53 AM
There is a Vogel 122-345-303 ET6900 automatic lubrication system that pumps way oil to the various sliding and rotating bits. Basically a pump on top of a 2.7 litre reservoir with a series of pipes and manifolds. It takes mains in, pushes oil out at times determined by an internal switch, and has a single feedback contact to the main CNC controller saying that all was well - there is also a manual button so that you can trigger the cycle on demand.
Starting the machine up all would be well but after a few minutes it would report 'Lubrication Error' - sure enough the fault light would be on on the Vogel. Pressing the manual button would clear the fault and all would be well for a few more minutes.
I was convinced that the oil level switch was faulty as it was measuring open circuit with a full tank, and the only literature that I could find, which was for a slightly later model, referred to the normally closed level switch. Should be easy enough to drop the reservoir from the main body and get at the float switch.
Well it would be were it not for one allen bolt in a totally inaccessible position behind the control box. This meant the whole caboodle had to come off. Only five wires and a pipe so not too bad.
Off comes the reservoir - slide the switch - no it's closed when the tank is empty (so NOT fail safe) so think again. Well there is an orange box inside that obviously is a custom made controller - a "Vogel IG 38" - again I can find details of later models but not this one :bang:
Still nothing ventured nothing gained - take the tin opener to it - 'open the box' as Hughie Green used to say, and see what's inside. Answer, quite a bit of electronics on two PCB's - nothing much to raise eye-brows.
More in hope than expectation I gently pryed out the one IC that was socketed, and re-inserted it and put everything back together so I could test it on the bench.
Having blocked the oil out port with a suitable bolt darn me if it didn't actually work :clap:
Time will tell if it was just oxidised IC contacts or if I've just scared the problem away for a while, but having re-installed the pump in the lathe she's now doing what she wouldn't do before :thumbup:
Post by: philf on December 16, 2019, 03:18:13 PM
........ take the tin opener to it - 'open the box' as Hughie Green used to say......
I must be in a pedantic mood tonight Andrew but I'm sure that was from Take Your Pick which was hosted by Michael Miles!
Post by: RodW on December 16, 2019, 03:23:21 PM
Post by: awemawson on December 16, 2019, 03:29:33 PM
As for Hughie Green or Michael Mile Phil, I don't remember - just what my grandparents told me :lol:
Post by: awemawson on August 11, 2020, 03:28:40 PM
I've not used the lathe for quite a while (been busy with Induction Furnaces!), but about ten days ago I thought that I should fire it up to show it that it's still loved. Trouble is, I couldn't get it to complete the initialisation routine (traverse over X & Z reference sensors, initialise the turret controller and tell it which tool station is currently selected,)
Now to be honest I've been putting off looking at it - didn't fancy a long diagnostic process again! But today was too hot to do anything else so I got stuck in.
Tried several times, usually I could jog both axis, and drive them to reference positions, then the controller would lock up. Nothing seemed to make sense until, poking through my decoding of the PLC code and correlating values with what I could read in internal registers I realised that I had a lubrication fault - there was the bit set in a register winking at me.
The system is very simple. At power on, the Vogel pumps for a few seconds, then goes into idle for a predetermined time, before again it pumps oil. There is a pressure switch monitored by the Vogel electronics that if it hasn't come up to pressure fast enough after pumping closes a signal contact registering the fault with the main Siemens CNC control.
In normal use the controller flags the error in text on the screen, but at start up this is blanked out by the words 'Initialise Turret' - yes OK I'm tying to!
No lube, no movement allowed says the Siemens CNC control and there you are locked up :bang:
Now a few presses of the manual operation button on the Vogel and again the fault has gone away - last time it took 8 months to come back but it looks like I need to pull it all apart again and at least check the pressure switch (internal, and inside the oil reservoir!)
(Pictures from last episode!)
Post by: RodW on August 11, 2020, 03:43:51 PM
Good you worked it out.
Post by: awemawson on August 11, 2020, 04:18:37 PM
There are various joints, again internal to the oil reservoir, that connect the pump to the switch and the outside world. A leak there is possible as it wouldn't show externally.
. . . I'll have to pull it apart and have a look-see over the next few days
Post by: AdeV on August 12, 2020, 02:57:23 AM
Post by: awemawson on August 12, 2020, 07:12:21 AM
I initialized the machine this morning (no issues) then deliberately disconnected the oil output from the Vogel. It took an amazing time to put on it’s red light to say that there was a fault. Probably about the same time as the dwell between pumping. Good oil flow, and when connected good oil pressure.
So I conclude that it’s probably the pressure switch or more likely the electronics. I’ll pull the orange controller out and go over a few soldered joints when I get a spare hour or so. Last time it seemed to clear when I reseated an ic but quite possibly I had actually disturbed something else!
Post by: awemawson on August 13, 2020, 06:10:29 AM
Photos taken of connections for reference, listed in my lab day book, wires tagged with 'flag ty-wraps' and I could then pull the unit out of the pump leaving the oily bits behind.
Case opens easily with the usual plastic ramp clips allowing me to pull the electronics from the box. Last time I didn't split the electronics - it consists of two PCBs separated by a third in a sandwich construction with soldered connections on headers holding it together. One main PCB has eight header pins and the other six, so I opted to unsolder the 'six pin side'.
Using my powered solder sucker and some flux the plated through holes seemed quite clean but rather than risk pulling the plated holes though the board I ran some low melting point solder into the joints - this stays fluid long enough just to pull the header pins out all together. A bit of a clean up with the sucker and flux followed by a squirt of brake cleaner and a scrub with a toothbrush and it's good for re-assembly when the time comes.
There is one socketed IC, three transistors, a bridge rectifier, five diodes, a handful of resistors and polyester capacitors and two electrolytic capacitors and two relays all powered by a tiny mains transformer. Also a rotary switch to set repetition time.
I will replace the electrolytic capacitors, try and open the relay cases and clean the contacts, then re-flow every joint on all three PCBs and also the terminal block.
Post by: awemawson on August 13, 2020, 10:12:44 AM
Meanwhile I took the covers off the relays to clean the contacts. Relay 1, is just a single pole change over - no drama, contacts cleaned with a slip of paper and switch cleaner / lubricant. Relay 2 (two pole change over) was a different matter. The armature was stuck in the operated position with no clearance to the magnet :scratch: At first I thought that the contacts must have welded shut, then I thought that the armature had been deliberately bent, but no, eventually I realised that there were two tiny paxolin 'bridges' - a flat bit of paxolin with a peg sticking out at both ends - deliberately put in the mechanism to force it into the operated position. Obviously a modification to make this module suitable for this particular lubrication pump. Simpler to leave the relay out and link the contacts but Vogel obviously thought differently!
Then I went over EVERY soldered joint re-flowing it with a bit of flux so hopefully any lurking dry joint will have been cured, and equally hopefully I haven't introduced any other faults!
. . . so now just waiting for those capacitors . . I hope that they arrive early . . 'double change over' in cottages tomorrow so times not entirely my own!
(Capacitor photos to make sure I put the replacements in the right way round!)
Post by: awemawson on August 14, 2020, 09:53:12 AM
Then it was just a matter of replacing the wiring, putting my fingers in my ears and switching on.
. . . . what could possibly go wrong ! . . well in this instance nothing thank goodness. It did precisely what it is supposed to. Initially started pumping showing 15 BAR on the gauge, then after a period switched off into idle mode for the prescribed period before starting over again
. . . .PHEW . . so at least I've not introduced other faults, but whether the long term intermittent fault is cured or not there is no saying :scratch:
Still, electrolytics changed, socketed IC removed, pins and sockets treated with switch cleaner and re-inserted. ALL PCB solder pads re-flowed, relay contacts cleaned, and interface terminal posts treated with switch cleaner before re-assembly - what more could I do in the absence of a replacement?
. . . fingers crossed for the NEXT 8 months :clap:
Post by: modeng200023 on August 14, 2020, 12:48:01 PM
John
Post by: russ57 on August 14, 2020, 10:44:49 PM
About to tackle a harman kordon avr2000 amp with dead channel. The circuit diagram (Iove the internet) suggests the pa module is basically direct coupled discrete power transistors. With luck the problem will be a) visible, b) accessible, and c) a component that is either available or at least a substitute.
-russ
Post by: awemawson on October 03, 2020, 03:03:18 PM
BUT . . I have absolutely positively determined what it is and in essence it is trivial - fixing it might be a different matter.
What is supposed to happen is that on power an, and at pre-set intervals then on, the pump starts up and the electronics 'looks' for the pressure switch to close within a certain time frame. If it does, all very well, it goes to sleep for a bit until the next pumping cycle. However if the oil pressure switch doesn't close for what ever reason the electronics flags an error to the CNC controller which promptly curls up it's toes and refuses to make any movements.
It turns out the the pressure switch is intermittent high resistance - I've linked it out temporarily and the machine works splendidly.
Now the pressure switch, so VERY conveniently, is immersed in the oil reservoir, so not the easiest thing to get at. System pressure is up to 18 bar so probably a 10 bar switch would be fine, but until I dig in a bit further I have no idea of thread size or terminations or body size, though it looks to be quite compact.
. . . still. . . . sell the positive . . I now know what the fault is that's eluded me for quite a few months. :thumbup:
Post by: WeldingRod on October 03, 2020, 08:27:21 PM
Sent from my SM-G892A using Tapatalk
Post by: awemawson on October 04, 2020, 06:29:53 AM
So yet again I pulled the Vogel pump off the machine to investigate the pressure switch further. It has a 24 mm hex body, an M10 x 1.00 mm mounting thread and screw terminals, with apparently an adjuster screw between them.
Now it is just possible that the screw terminals were giving the high resistance, but they were nice and tight, and it's just possible that tweaking the adjuster a bit might kick it into life, but having got so far now I want to replace it. Sadly it's not really possible to test it without putting it all back together.
A quick web trawl suggests that they may well be available as a spare - I'll make some phone calls on Monday
Post by: awemawson on October 04, 2020, 09:13:28 AM
Not sure about 1/4" Lucar connectors immersed in oil - I may do better to solder leads directly on - but comments welcome !
Post by: Pete. on October 04, 2020, 09:54:59 AM
Post by: mattinker on October 04, 2020, 10:29:34 AM
No harm from immersing electrical contacts in oil far as I know Andrew. The fuel pump on my bike even had un-insulated connections in the fuel cavity.
I agree with Pete, my K100 has the same sort of connections in the tank! I would have thought that it would be positively advantageous, no corrosion
risk!
Cheers, Matthew
Post by: WeldingRod on October 04, 2020, 11:21:32 AM
Sent from my SM-G892A using Tapatalk
Post by: awemawson on October 04, 2020, 12:20:37 PM
My concern was any sulphur in the oil would possibly promote corrosion, and way oil is sometimes sulphurised.
. . . but I'm no chemist :scratch:
Post by: djc on October 04, 2020, 02:04:41 PM
Post by: awemawson on October 04, 2020, 02:09:45 PM
a/ Painting the connections with 'liquid insulation tape'
b/ fitting a pipe extension out and above the oil and putting the switch in the electrical box, but need to check if there is room.
I'm getting very adverse comments re oil / sulphur & copper on the welding forum - thread here:
https://www.mig-welding.co.uk/forum/threads/any-oil-chemists-on-the-forum-copper-corrosion-in-sulphurised-oil.105672/#post-1673615
Post by: RussellT on October 05, 2020, 04:01:02 AM
By the way I wondered if the original numbers on the pressure switch said 12.0 Bar.
Russell
Post by: mattinker on October 05, 2020, 05:31:11 AM
I would be inclined to inclined to autopsy the switch, turning the end down on the lathe to release the insulation. I'm curious about where the fault actually is? I know it won't fix anything, but interesting to see whether corrosion is the cause of the problem and whether the sulphur in the oil is corroding the brass.
Cheers, Matthew
Post by: RotarySMP on October 05, 2020, 05:38:32 AM
Sorry I didn't check this thread earlier. I have attached the wiring diagram for the Vögel IG38 I found on line somewhere. Doen't add much to what you already know, but I thought I'd post it for completeness.
Mark
Post by: awemawson on October 05, 2020, 11:19:55 AM
Matthew yes I had that in mind - always like to see causes, but with this one I want to make an adaptor so the I can pump it up and check it out of the pump before destroying it.
Mark, thanks for that - added to my Vogel library :thumbup:
Post by: David Jupp on October 06, 2020, 05:45:33 AM
Post by: awemawson on October 07, 2020, 04:09:20 AM
Interestingly when I came to the electrical connections, one of the original crimped spade lugs had already fallen off and the second fell off when I touched it . The copper cable where it emerged from the crimp had completely corroded through! So I reckon that there is a good chance that the original pressure switch is actually fine. I must make an adapter up to test it under pressure.
Cutting the cable back and crimping on 'female spade lugs' I assembled it and slavered 'liquid electrical tape' all over the crimps externally, hopefully excluding oil ingress in future. Messy runny stuff to use !
Can't put it back in the oil tank until this gunge has set so later this evening probably.
Post by: russ57 on October 08, 2020, 06:58:43 AM
Seems highly likely that was the issue.
-russ
Post by: awemawson on October 08, 2020, 07:34:07 AM
I put it all back together again this morning and re-installed it. All seems to work as it should and I’m now going through the myriad of places oil is supposed to emerge checking that they are all lubricated ok
Tiny volumes in some places so not immediately obvious.
Post by: awemawson on October 08, 2020, 10:42:18 AM
Assembling the switch to a test pump and guess what - the switch is INNOCENT - apply pressure switch closes release and switch opens.
I was just packing up and processing the photographs when I realised that there was a possible / probable miscarriage of justice - looking at my photograph of the Fluke meter it was on its next to HIGHEST ohms range not it's lowest :bang:
Of course I'd dismantled everything and put all away, but there was nothing for it, there would have to be a re-rial in the light of this new evidence. I put everything back together repeated the test and OK the accused WAS innocent, and released from custody.
. . at least I now have a spare pressure switch.
As for the original fault, I believe that the copper wires had corroded where they were crimped - possibly due to the sulpher in the oil, or maybe other causes, and the outer plastic sheath had held the bits in intimate contact, often adequate and sometimes not. Remember that the plastic sheath is retained by the outer crimp on these spade lugs.
Post by: Muzzerboy on October 08, 2020, 12:59:49 PM
I recall a time when RS insisted on eradicating any trace of the manufacturer and putting their own part numbers on components instead. That was never going to last. Quite amusing the lengths they went to!
Post by: awemawson on October 08, 2020, 01:14:07 PM
Post by: Muzzerboy on October 08, 2020, 03:32:51 PM
Post by: awemawson on October 08, 2020, 04:38:53 PM
Post by: Pete W. on October 09, 2020, 05:56:20 AM
I’ve a couple of Avo 8’s but my ex WD Avo 40 recently died from a fatal fall onto concrete
I, too, have an AVO 8. The 15 volt dry battery (high ohms range??) is getting a bit hard to find these days. I seem to remember seeing mention of a third party DC-to-DC converter to generate the 15 Volts from the accompanying 1.5 Volt U2 cell (aka D-cell). How it was switched on and off remains a mystery to me!
I rarely use the AVO 8 these days - I have a Fluke 8020A. My Bank Manager lent me the money to buy it. :D :D :D One problem with the early 8020A instruments was that the LCD display got 'poisoned' and lost legibility. Fluke ran a scheme whereby, for a reasonable fee, they would replace the display with an improved version and re-calibrate the instrument. That was many, many years ago and the replacement display is still going strong.
I remember lots of folklore concerning RAF AVOs being 'destroyed' (or maybe not?) after the 1939-1945 war but that might be considered as off-topic! As might attempts to trace the evolution of AVOs' manufacturers - Douglas, Automatic Coil Winders, AVO Ltd., Marconi Instruments et al!
Post by: awemawson on October 09, 2020, 06:32:45 AM
I remember that the Douglas Coil Winders were being assembled in the basement, but also in use winding the non-inductive precision resistors - quite a hive of industry.
Shorty after that they moved to Dover, and I persuaded my parents to buy me the Avo 40 for Christmas from a small ad in the Evening Standard.
Post by: Pete W. on October 09, 2020, 07:07:14 AM
Some years later, Taylor Instruments had the same parent company as the then proprietors of AVO (I guess Marconi Instruments?). A Taylor sales representative came to discuss panel meters for a current project. In conversation, he said that when Taylor's manufacturing load was droopy, they'd be tasked with making a batch of AVOs to 'fill the hole'. He displayed the salesman's consummate skill in keeping a straight face while he assured us that 'of course, a Taylor AVO is better than an AVO AVO'!!! :D :D :D
Post by: modeng200023 on October 09, 2020, 07:13:03 AM
This brings back good memories :clap:
Post by: Sea.dog on October 09, 2020, 11:34:25 AM
I’ve a couple of Avo 8’s but my ex WD Avo 40 recently died from a fatal fall onto concrete
The 15 volt dry battery (high ohms range??) is getting a bit hard to find these days.
Easy to source and a lot cheaper than when I last looked - https://www.ebay.co.uk/i/273806052629?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=273806052629
Post by: Muzzerboy on October 09, 2020, 12:20:48 PM
At one time I used those little miniclip probes with voltmeters. It was when holding both of them onto a 3 phase supply that I was able to experience the feeling of 3 phase across my hands. Could have killed me I suppose but here I am. I have to say it hurt like f***. Little strands of wire hanging out at each probe aren't clever.
Back then we were allowed to sign equipment out for home use. But we had brain dead a hole managers who thought standing outside the factory door at 5:29pm would motivate the engineers. I signed out an AVO 8 for a homer project and one of said a holes gave me a dirty look on the way out. Consequently I kept it longer than I'd planned and then the company was bought out and closed down, making everyone redundant. On the upside, the all a holes also got made redundant and I still have the AVO 8 in my workshop.
Post by: awemawson on December 01, 2020, 09:00:58 AM
Advertised on eBay a couple of months ago were a pair of PCM swiss made powered tooling holders - a straight one, and a 90 degree one. The description was vague, and although they looked to be VDI holders the seller couldn't say if they were VDI 20 / 30 / or 40. A search on the PCM part number of the straight one (as it showed in the advert photo) implied that it was VDI40 as I need but was no means definite. However the drive end of these holders looked to be identical to the Beaver ones that I had had to modify on my existing holders.
Anyway no point in getting too excited - he was asking silly money and had already rejected a more reasonable off that I made a few weeks back. Well, he went through the hoops of re-listing the items four times so last week I made a slightly increased offer and to cut a long story short they have just arrived. A quick inspection shows the bearings to be reasonable and although they need a clean up they are in infinitely better condition than the previous ones that I got that were seized solid and needed new bearings and seals.
The straight holder fits 'as is' directly on to the tool turret with no modifications needed, and the drive engages nicely. The 90 degree one will need to be modified (as I had to with the previous one) as the heel of the mounting face fouls on the centre disk on the turret. About 1/4" needs to be removed - perhaps a bit less - to clear the disk, but I've done it before so can do it again!
. . .so I'm a happy bunny today :clap:
Post by: tom osselton on December 01, 2020, 07:29:00 PM
Post by: awemawson on March 01, 2021, 09:29:05 AM
Most hydraulic chucks, be it collet or jawed, have a draw tube co-axial with the spindle which is pulled or pushed by a remote co-axial hydraulic cylinder. On the Beaver the chuck has the cylinder built into it, and has two ports (open & close) in the face of it's rear surface that mate with similar holes in the spindle nose where an O ring is trapped to seal the oil.
Now my main chuck is a Pratt-Burnerd 1749-02780 which I very much doubt was a special for Beaver so it must conform to some spindle nose standard (I assume). The lathe spindle 'seems' to be an "A2-6" standard spindle shape with the two hydraulic ports added.
Anything conforming to this standard is remarkably rare - in the last few years I've found one chuck like mine in the UK that the seller wanted really silly money for, and one rather beaten up collet chuck that was a fair price, but no collets and being in Canada transport killed the deal.
So when a collet chuck using this same system turned up on UK eBay complete with an almost complete set of collets I got quite excited. Conversations with the seller revealed that it was off a Beaver lathe - excitement raising to fever pitch - soon to be dashed when I find that it was off a Beaver TC10 lathe (mine is a TC20) that has an A2-5 sized nose so not directly compatible.
Explaining to the seller how limited his potential market was persuaded him to release it to me at a very reasonable price (£200 inc carriage) which is worth it for just the collets.
So LOADS of googling shows that at least two firms make a converter plate from A2-6 nose to A2-5 nose - they don't have the bores for the hydraulics but if the adaptor plate is fat enough there might be room for some drilling of oil galleries converting from the collet chuck's 60 mm PCD to the spindle noses 84.2 mm PCD. Both are 6 mm diameter.
I envision drilling blind holes into the two mounting faces of the adaptor at the two PCD's with a cross drilling joining them which can be blanked of with a sealed grub screw, but this depends on the adaptor plate being fat enough and actually managing to buy one!
Absolute 'back to the wall' solution is to make the adaptor plate myself, but it has rather a lot of precise features and needs to be absolutely concentric so not something to knock up in a wet weekend.
I have thoughts of 3D printing a model to prove the concept.
. . . the other issue is actually handling the original chuck - nowhere above to put a block and tackle and it weighs 47.2 kg :bugeye:
Post by: Muzzerboy on March 01, 2021, 01:03:20 PM
Post by: awemawson on March 01, 2021, 01:57:52 PM
Not that bad really with a handled hex driver - usually it'll be for small runs of parts.
Numerous phone calls today are bringing me round to thinking I may HAVE to make the adaptor plate. So if I do I'll pretty certainly do it on the manual lathe on an expanding mandrel between centres so that I can work on both faces and have some hope of maintaining concentricity.
So where do I find a 45 mm slice off a 170 mm bar of something nice to machine?
Post by: Spurry on March 01, 2021, 02:16:06 PM
So where do I find a 45 mm slice off a 170 mm bar of something nice to machine?
I've always found M Machine pretty good.
http://preview.m-machine.co.uk/CATALOGUES/metals%20catalogue.pdf
Post by: nrml on March 01, 2021, 03:09:52 PM
Post by: vintageandclassicrepairs on March 01, 2021, 03:16:16 PM
I must be lucky where I live ? There are a couple of engineering workshops close to me where I can buy off cuts
usually a donation to the tea kitty :beer:
When I had a job, the scrap metal skip was never safe LOL
John
Post by: awemawson on March 01, 2021, 03:31:56 PM
https://www.ebay.co.uk/itm/Black-EN-24T-817M40-Metric-Rounds-50mm-to-200-mm-various-lengths/193338176672?ssPageName=STRK%3AMEBIDX%3AIT&var=493530085900&_trksid=p2060353.m1438.l2649
Post by: philf on March 01, 2021, 04:12:04 PM
So if I do I'll pretty certainly do it on the manual lathe on an expanding mandrel between centres so that I can work on both faces and have some hope of maintaining concentricity.
Andrew,
I'd turn one side, put the necessary holes in, and mount it on the lathe to turn the other side.
Just like finish machining a backplate for a chuck.
Phil.
Post by: awemawson on March 01, 2021, 04:29:01 PM
I'd certainly have to make several trial pieces before committing to the final one but I do agree it's the best way of ensuring concentricity !
Post by: AdeV on March 02, 2021, 03:14:40 AM
Scary CNC machining that second side Phil when you can't even see the work piece :bugeye:
I'd certainly have to make several trial pieces before committing to the final one but I do agree it's the best way of ensuring concentricity !
I've got some big chunks of machinable wax if you'd like to do some trial pieces....
Post by: WeldingRod on March 02, 2021, 10:39:35 AM
Sent from my SM-G892A using Tapatalk
Post by: awemawson on March 02, 2021, 10:56:10 AM
Now I'm working on how the devil I'm going to be able to lift the 47.2 kg chuck off. On that side of the lathe there is only a 30" walk space. No strong points above the chuck, and the gap from floor to lathe base is too small for the wheels of an engine crane.
One possibility is a jury rigged gantry rigged across the lathe from that walk space to an even smaller one at the rear.
Another possibility is a home made 'cantilever crane' with it's jib counterbalanced by lumps of concrete and able to operate in the 30" walk space.
It would be nice to make something more 'universal' as lifting can only get worse as anno domini pass :scratch:
Post by: awemawson on March 02, 2021, 11:15:46 AM
By making a custom 'fork extension' for my Hyster 2.5 ton fork lift truck I may be able to come at the lathe from the headstock end (all the cupboards and things there are on wheels anyway) and project the extension over the lathe down the Z axis. Given a suitably strong net sling for the chuck the fork lift can do the raising and lowering, and if I slide a pole 'up the spout' of the lathe and through the chuck as a back stop hopefully accidents can be prevented.
It will need to be a 6 foot long extension at least - probably some scaffold tube with custom fixings to the existing forks. I'll do some tests but I don't suppose 6 foot of scaffold pole will object too much to 47 kg bouncing on it's far end !
Post by: Pete. on March 02, 2021, 02:55:53 PM
Post by: awemawson on March 02, 2021, 03:23:03 PM
It'll mean bolting a socket down to the concrete floor - I'll explore the geometry and see if it's possible to swing in round for lowering - as you know it's a tight space !
Post by: Pete. on March 02, 2021, 03:32:31 PM
Come to think of it, I might have a 6" box section post at work.
Post by: mattinker on March 03, 2021, 05:10:06 AM
A tight corner! It's the endless making things to make things syndrome! Love it most of the time!
Cheers, Matthew
Post by: awemawson on March 03, 2021, 06:13:41 AM
I've come up with what I think is probably a much better solution: The Beaver TC 20 has MASSIVE M30 lifting eye sockets in it's equally humongous base casting, two of which are just inside the sliding door. Using Pete's suggestion of a bi-fold davit arrangement, if I build off a substantial plate bolted to these two mounts I don't think there'll be too much problem with two point rather than three point mounting. OK the plate will have to sustain significant torque with the jib extended and 47 kg dangling on it - but hey they are M30
Now in my mind I have something like the hoists used to remove mobility scooters from the backs of cars - darn me I gave one away a few years back - but they will already have the suitable articulation pivots and linear actuators.
This way the whole shebang can be fitted and removed by just undoing two (admittedly large) bolts.
So the hunt is on for a redundant mobility hoist or other such thing so please keep your eyes skinned !
(Picture is of the sort of thing I'm looking for, sadly not one that I yet have!)
Post by: awemawson on March 03, 2021, 11:20:12 AM
Just a fairly rough bit of carpentry - the final version will be welded together substantial chunks of steel with various reinforcing gussets.
. . .but it helps me see if it will work and I think that it will :thumbup:
Post by: awemawson on March 04, 2021, 09:54:47 AM
It was then that I realised none of my offcuts of 6 mm MS plate were big enough to cut the base, which is approximately 1 M x 150 mm. No problem, I have a stash of sheets in my container. Third one down in the layer was a full 1.5 M square, so a bit of huffing and puffing and the top two sheets were removed (6 mm plate is bally heavy to manhandle!) and I walked the chosen one to the door awaiting attention from the forklift. Plate grab suitably attached and I moved it to the welding shop, laying it on the pump up trolley. This lets me get it overhanging the plasma table, and a few more grunts and puff got it place.
I've cut the base plate with a rectangular hole to receive the fixed upright, so that I can weld both sides of the plate. I also cut four reinforcing fillets for this upright, but I fancy they may not be large enough. At least in the fore and aft direction I can put a much larger one perhaps
Picture shows bits temporarily held by magnets while I chew over ideas!
Post by: Pete. on March 04, 2021, 03:57:37 PM
So this afternoon I made a 'proof of concept' wooden mock up to help me visualise the various lengths of arms and angles involved.
Just a fairly rough bit of carpentry - the final version will be welded together substantial chunks of steel with various reinforcing gussets.
. . .but it helps me see if it will work and I think that it will :thumbup:
I must confess that I envisaged a horizontally-swinging bi-fold arm, rather than a luffing gib. Either would work just as well but with the horizontal arm you don't need anything to pivot on the post axis.
Post by: awemawson on March 04, 2021, 04:12:07 PM
If however there is room to fix a compact hand operated winch on the end of your arm system it might simplify things !
Post by: vintageandclassicrepairs on March 04, 2021, 04:37:13 PM
A vertical rib length ways along the 1.5m to form a virtual angle iron, plus a couple of ribs at 90 degrees to the long rib near the post and the holding down bolts would help stiffen the base and make it resistant to twist ??
John
Post by: awemawson on March 04, 2021, 04:41:20 PM
Post by: smiffy on March 05, 2021, 04:12:34 AM
Post by: awemawson on March 05, 2021, 05:07:40 AM
If I can source a suitable winch / hoist then I'll go with Pete's horizontal arm version as it has several advantages, and even better if I can source a hand powered version as it then becomes entirely self contained. All the cheap ones are what I call 'ratchet winches' where to reverse them you flip the pawl of the ratchet in the opposite direction and my experience of them hasn't been good. They tend to jam in one direction and anyway are rather coarse in their positioning - OK for removing the chuck - not so good putting it back.
What I really want is an affordable 'Worm Winch' - these have the advantage of being not only fully reversible as the worm self holds, but enable far more precision in movement. But they are an order of magnitude more expensive :bugeye:
Measuring up this morning I find that I have a full 12" clear above the chuck so enough room to do it given the right winch :thumbup:
Post by: smiffy on March 05, 2021, 05:10:33 AM
Post by: awemawson on March 05, 2021, 07:26:17 AM
I've actually found what looks to be a suitable worm operated hand winch - a bit pricey but there you go :med:
Should be here on Monday - I've opted for webbing rather than wire rope.
Post by: kayzed1 on March 05, 2021, 10:32:28 AM
Post by: awemawson on March 05, 2021, 11:28:27 AM
It's for 'once in a blue moon' use and I feel that the total control turning a mechanical handle gives is well worth the minor effort.
Post by: awemawson on March 06, 2021, 09:34:54 AM
A/ I made up a taller 'main mast' - this time 42" tall to use the headroom over the chuck
B/ I cut the 'Bi-Fold' arms - conveniently from the previous shorter mast as each are 15" long
C/ I drilled the 12 mm pivot holes the the bi-fold arms and made up 'anti-crush' tube for inside the box section (it's 3 mm wall but best to reinforce it)
D/ I made up a pair of pivot brackets to weld on the mast but decided that they were too wimpy
E/ I re-drew the pivot brackets so that they encircle the mast with a 6 mm x 10 mm band
F/ I made a tab to weld on the end of the far arm to accommodate the width of the winch base then drilled and tapped M8 to fix the winch in place.
I still need to convert the base into a box beam, weld on the mast and fit reinforcing fillets, and make and fit a roller for the lifting webbing on the far end of the end beam.
Post by: awemawson on March 06, 2021, 12:46:47 PM
I cheated actually as when looking for suitable round stock I found something I'd chopped off some mechanism some time in the past that already had a spool shape in it! I just had to turn it to length and sleeve it down to 10 mm !
Bits needed chopping off the box section to mount the spool and then it was just a case of drilling the remaining vertical cheeks and putting a bolt in (yet to find one of proper length.
Then re-assembling the winch onto the arm and fitting the webbing it was ready to test. Finding a 56 lb weight I hooked it on and wound it up and down about 2 foot.
Cranking the handle there was an alarming graunching noise in a couple of places, and examining the gear on the handle shaft there is already visible wear and it looks horribly as though it's made from aluminium alloy - surely not :scratch:
OK gears have to wear together in but heck this is lightly loaded and has only turned a few dozen turns - it can't be right :scratch:
56 lbs is about 25 kg and this winch is rated at 170 kgs :bugeye:
Post by: Sea.dog on March 06, 2021, 01:39:59 PM
Post by: kayzed1 on March 06, 2021, 02:35:54 PM
Post by: Muzzerboy on March 06, 2021, 02:36:43 PM
Post by: awemawson on March 06, 2021, 02:52:03 PM
Maybe the two will wear in in time to a happy relationship having knocked the high spots off each other !
I'll add another 56 lb weight tomorrow, which will bring it up to my expected full load, and wind it up and down a few times, but I will re-grease the gears first.
Post by: Spurry on March 06, 2021, 02:52:52 PM
Post by: awemawson on March 06, 2021, 02:56:05 PM
Post by: Spurry on March 07, 2021, 06:04:46 AM
Post by: awemawson on March 07, 2021, 07:02:25 AM
I cut a pair of angle fillets for the main mast fore and aft (Z axis) reinforcement but there's not much room to add anything more to the abeam (X axis) direction. I think I'll weld together what I have and see how much flexing that I get, as I'm concerned that the whole thing is getting pretty heavy. Make it too heavy and it defeats the object of having it !
To stop the base twisting I have both 3" and 4" box profile that I could weld on underneath, but it's the weight issue. If the twisting is too great I 'could' add a detachable outrigger resting on the floor :med:
No welding today - I have a fencer working and it's amazing how often he needs words. I've already straightened his Eastwing hammer on the 60 ton press :clap: )
Post by: mattinker on March 07, 2021, 07:30:09 AM
How smooth is the worm? That's what's going to determine how long it lasts!
Cheers, Matthew
Post by: awemawson on March 07, 2021, 07:56:54 AM
I presume I'm right in thinking that even though the spur gear is canted over at an angle (lead angle of the worm?) a straight cut involute without crowning cannot be an exact fit, just an approximation, needing scallops out of the centre of the tooth width that use is generating :scratch:
Gear experts please comment !
Post by: Spurry on March 07, 2021, 08:54:53 AM
Pete
Post by: awemawson on March 07, 2021, 10:07:49 AM
Post by: WeldingRod on March 07, 2021, 02:59:42 PM
Non enveloping has straight wheel teeth but with a spiral angle. Single is when the wheel is grooved and the teeth are shaped into a curve: you can hob to get there. Double enveloping has an hourglass shaped worm and a shaped wheel. Load capacity goes up with number of envelopes.
You probably need to deburr the worm ends. Also, the end of the worm should not be touching the wheel's teeth. It may be installed in the wrong axial location.
If you want to wear.it.in, I would start with lower load or no load and wash the chips out regularly. Might feed it some pumice mixed into grease.
Sent from my SM-G892A using Tapatalk
Post by: Pete. on March 08, 2021, 01:35:31 AM
Matthew, visually it looks OK but it's not the easiest of things to get a good view of. Once the start of the worm has meshed it feels pretty smooth, it's just the initial graunch as the start enters the spur gear.
I presume I'm right in thinking that even though the spur gear is canted over at an angle (lead angle of the worm?) a straight cut involute without crowning cannot be an exact fit, just an approximation, needing scallops out of the centre of the tooth width that use is generating :scratch:
Gear experts please comment !
It can be either way but the scalloped arrangemet gives more tooth engagement. The bigger problem as I see it is that the worm starts are engaging with the gear. That says to me that the worm is too short because the start of the worm should never be in engagement. Perhaps the worm can be moved along with spacers to move the end of the worm away from the gear centrline on the loaded side?
Post by: vtsteam on March 08, 2021, 09:38:45 AM
Cranking the handle there was an alarming graunching noise in a couple of places, and examining the gear on the handle shaft there is already visible wear and it looks horribly as though it's made from aluminium alloy - surely not :scratch:
Is it?
Post by: awemawson on March 08, 2021, 09:49:06 AM
So today I welded the crane components together. I consider myself an 'occasional good welder' in the sense that occasionally I can do a good weld :lol: But not consistently, especially on something like this with loads of 'out of position' welds. They are certainly strong enough, just not as pretty as I'd like! The box section is galvanised and I'd thought I'd ground off the zinc where I was welding, but it is obviously much thicker than I thought as it was popping and flaring at times.
Not cleaned anything up just now, I wanted to evaluate it on the lathe and see how much twist there is when lifting those two 20 kg weights. Answer surprisingly little :thumbup: I'll sleep on it but at the moment I don't think that it needs further ribs below the base though I have cut a pair of 60 mm diameter fat washers for the 30 mm holding down bolts to spread the load a bit.
I was able to lift the pair of weights - totalling 40 kg - without any alarming bends or creaking so at the moment I'm thinking just to clean it up, dress the welds, and move on.
The 60 mm thick slice of 170 mm EN24T has arrived to make the chuck adaptor so there's work to do !
Post by: awemawson on March 08, 2021, 09:53:05 AM
Post by: vtsteam on March 08, 2021, 10:31:20 AM
Post by: Sea.dog on March 08, 2021, 10:34:51 AM
I'd feel a lot happier with a double beam at the post end, one above, and one below the pivoting arm.
Post by: vtsteam on March 08, 2021, 11:08:53 AM
OTOH the end arm looks severely twisted on the pivot in photo 5, but I'm assuming that's a camera distortion.
Post by: vtsteam on March 08, 2021, 11:41:37 AM
In that case I'd get rid of the single bolt top pivot, then weld ears, top and bottom, on the main arm, and fit the swing arm between the ears and bolt/pivot through.
Similar to how you did the main post pivot. You can leave the swing arm longer inside the ears (for more bearing surface) if you don't cut off the arm square, but cut an arc with the pivot-end radius for closer clearance.
Post by: vtsteam on March 08, 2021, 11:57:57 AM
Post by: mattinker on March 08, 2021, 12:01:09 PM
Cheers, Matthew
Post by: awemawson on March 08, 2021, 12:20:38 PM
This crane is probably only going to be used half a dozen times, mostly while machining the chuck registers on both sides of that billet of EN24T - it's not as though I'll be changing chucks every day !
. . . but thanks for your concerns - I certainly don't want to drop the 3 jaw - that's a beast of a chunk of expensive steel
Post by: awemawson on March 08, 2021, 12:30:57 PM
"OTOH the end arm looks severely twisted on the pivot in photo 5, but I'm assuming that's a camera distortion."
Yes Steve that is mainly the camera angle compounded with the angle that the arm is set.
The worst case is swinging the weight (chuck) out of the lathe - the centre arm pivot has to fold to clear the door opening then unfold so that the upper arms are in line but pointing out of the enclosure. In this direction the bracing of the upright post to the base plate is at it's weakest, and I expected the base plate to twist, but any twist is very minimal probably due to the close proximity of the right hand hold down bolt.
Post by: awemawson on March 09, 2021, 06:33:21 AM
I had thought to make up a rope net sling but that probably would give too much stretch :scratch:
So I intended to roll up an encircling sheet metal strap that could be bolted up tightly incorporating a lifting eye, and thinking that if I could perhaps pick up an indentation in the chuck periphery (the jaws for instance) it would be more secure from slipping on the metal to metal contact of chuck to strap.
Rotating the chuck by hand, what do I see but two 'bungs' screwed in the periphery, both stamped "1/8 NPS", in what would be an excellent place to screw a plate with a central lifting eye. Taking them out they obviously block oil ways, probably an artefact of the manufacturing process but the length of thread is pretty short - are they strong enough? Now 1/8" NPS (an American pipe thread I believe) is 27 TPI and approximately 10 mm o/d. Getting out my Imperial thread gauge to check that it IS 27 TPI I find that there is no 27 TPI blade, but there are two 26 TPI blades! This is a Moore and Wright No 800 thread gauge that I bought brand new when I was at school - I remember drooling over the tool shop window and convincing myself that I NEEDED that thread gauge set ! Now it just so happened that I acquired a second No 800 M&W thread gauges set in a job lot of tools last year, getting it out it didn't have 27 tpi going straight from 26 tpi to 28 tpi. ! However it DOES have a 25 TPI blade not in the other set !
Back to the chuck. Continuing rotating it by hand what do I find but ANOTHER bung about 180 degrees from the others, this time marked "1/2 UNC" - much more promising. Taking it out there is quite a long length of female thread and 1/2" UNC is reasonably strong - should be good to dangle 47 kgs off (I hope) BUT the position of the thread in the periphery of the chuck is far to far forward to be the centre of balance. However, on the face of the chuck in the same rotational alignment is another threaded hole that turns out to be 3/8" UNC. If I can make a stout bracket that is fixed by these two threaded holes, but extends further back to where I think the centre of balance is more likely to be, I maybe have a winner, and this will be far more secure than a strap wrapped round (I Hope)
. . . . Off to hunt for heavy section large angle iron !
Post by: awemawson on March 09, 2021, 11:51:57 AM
Simple bit of cutting, guesstimate marking out, drilling and tapping - all went well except for breaking a brand new 3/8 UNC taper tap :bugeye:
. . . Why ? because I forgot when power tapping that the new motor on my Bridgeport hasn't got slow forwards and slow reverse next to each other on the rotary switch, it's slow forward and fast forwards !!!!!!!
All seems to fit nicely - I've stolen a 5/8 UNC lifting eye from the Eurospark sinker EDM for the present. It's skirt fouls the 1/2" UNC top fixing bolt so I'll have to make a stand off fat washer for it to screw down onto. But that's a job for tomorrow.
Of course I don't know that where I've put the lifting eye is on the centre of balance, but it's nearer to it than the single 1/2" UNC tapped hole.
Post by: awemawson on March 10, 2021, 08:37:26 AM
I have to decide what media I will use for test cuts of the A2-6 and A2-5 chuck registers - cast aluminium blank or machinable wax
I have to recess a set of jaws to grip the 170 mm blank, both the test ones and the final work
I have to draw up the profiles of the A2-6 and A2-5 spindle / chuck registers in FeatureCAM
So to help me decide what media to use I did some experimental turning with machinable wax from my stash - this is some that I made years ago and it's been maturing in a cupboard. The swarf that comes off tends to be long and stringy - on a manual lathe I can sucessfully hoover it up as it comes off by holding the suction nozzle to the lathe tool, but that's hardly possible on the CNC lathe So I turned both sides of a smaller puck that I had already cast and did some experiments. Yes it hoovers up nicely with the workshop vacuum cleaner. Why is this so important? - Well I suspect that if left in contact with the oils from way lubrication, and residuals that are in the enclose, it will make a sticky goo that could well block the various distribution pipes.
Now if I'm using M/W do I cut a blank from a slab that I have that is a bit thin (but it's only the faces that I'm interested in) or do I cast a custom blank from a rolled up mould. This stuff does take quite a while to get to moulding temperature as it has to have a very gentle heat, so I'll probably try with what I have to hand.
To cast a blank in aluminium would eliminate the 'sticky goo' issue but there's quite a volume to that blank and again a session of mould making would be needed.
So first off M/W it is !
Post by: tom osselton on March 10, 2021, 03:06:44 PM
Post by: awemawson on March 10, 2021, 04:35:33 PM
https://www.madmodder.net/index.php/topic,7213.msg77229.html#msg77229
I got hold of a sack of plastic injecting pellets they were MDPE and I bought candle wax pellets in large quantities on eBay. IIRC it was about a 50:50 mix and gentle warming, wax first then stir in the MDPE.
Some people use actual candles and plastic bags.
Post by: AdeV on March 11, 2021, 01:28:10 PM
Some people use actual candles and plastic bags.
Been there, done that....
I used some plastic pellets I bought from a supplier (they were LDPE rather than medium density), and some scrap candle wax I bought off eBay to make mine. Ratio is 4:1 wax to plastic, although there's plenty of scope for variation. I think the late John Stevenson compared a sample of mine with some commercial stuff, mine was a bit softer, but not a lot in it.
Post by: awemawson on March 11, 2021, 02:33:41 PM
Thinking about it I seem to remember that I got my wax pellets from you Ade :scratch:
It all machines nicely but sharp edges can be fragile.
Post by: Muzzerboy on March 11, 2021, 03:18:28 PM
Post by: awemawson on March 11, 2021, 03:30:57 PM
You have to be careful not to set the wax on fire by heating too fast !
Post by: awemawson on March 12, 2021, 10:10:02 AM
I've inserted PTFE shims in the crane pivots and done the bolts up with lock nuts - previously if tight enough to reduce play, pivoting would undo the nuts making it slack again. Now the pivots can be tightened quite tightly and yet the arms still pivot with minimal play.
Crane now removed from the machine to allow me to install jaws to hold the 170 mm billet of EN24T. In my box of used jaws I found a set that are already very close to size - in an ideal world I'd prefer a bit more jaw thickness on the outside of the billet but the only other ones I had would need masses of material removing precluding their use in the future for small (more usual sized) things. I console myself with the thought that the cutting forces will mainly be towards the chuck in the Z direction pressing the billet into place. I've yet to finish bore them for concentricity but they are very close.
To fit these jaws, previously used by someone else on a different lathe, I had to modify the Tee nuts as they were 'bottoming out' before gripping - not good in use !
This meant steaming up the Beaver Partsmaster for the first time in ages, and darn me the Kurt vice had decided to seize solid so that took a bit of freeing of. Anyway the upright of the Tees was duly reduced by 5 mm and on went the jaws.
. . . but that's enough for today.
Post by: Muzzerboy on March 12, 2021, 12:08:59 PM
Post by: jiihoo on March 12, 2021, 05:17:25 PM
I was staring and then zooming at the picture of the two 26 TPI thread gauge blades and I am quite certain that the first one reads "25". A somewhat smudged "5" but a 5 nonetheless. The upper left of the number looks like it has a sharp corner and it looks like there might be a break below the horizontal bar on middle left.
Post by: awemawson on March 13, 2021, 05:54:47 AM
Post by: jiihoo on March 13, 2021, 09:16:27 AM
Post by: awemawson on March 15, 2021, 09:10:59 AM
I've still to form an undercut in the corner of the jaws, but as this again considerably weakens them I may bevel the billet on the manual lathe so that it can sit snugly without the undercut.
I've made some progress on the CAD side, downloading a DXF of a Kitigawa A2-6 chuck and importing it into FeatureCAM and deleting all but the A2-6 back end. I've got a working model, but need yet to match the tool crib on FeatureCAM to what I have on the lathe.
I'll put pictures of this up later when it's progressed a bit more .
Post by: awemawson on March 15, 2021, 09:33:53 AM
The pre-cast slabs of M/W that I already had are a bit too thin but I decided to cut one anyway on the band saw, but also cast one to size thereby using up the bits from bandsawing the slab.
I am slightly concerned that the clamping force of the lathe chuck will be too much for the machinable wax, and this thinner billet can be used for tests. The lathe has two pre-set clamping levels - high and low - I need to investigate if I can reduce the pressure of the low setting even further. (Selection between the two levels is by M codes)
So taking my life in my hands I raided the kitchen and found a nice 7" cake tin with a 'drop bottom' Ideal at 177.8 mm diameter as it is just over the 170 mm of the steel billet and the M/W shrinks considerably on cooling.
Then I went hunting for the pot that I had previously melted the M/W in - turns out that it was a Kennedy 'Red Hot Dip' pot for their version of Crocell tool dip. Evidence of previous use was obvious - there was still some M/W in the bottom!
So, pot set to melt - it's thermostatically controlled and I took the M/W up to 150 C very slowly giving frequent gentle stirs to get in homogeneous. I wanted to pour it at the lowest possible temperature to avoid major shrinkage.
Now it is poured I'll leave it over night to cool and shrink-release from the cake tin. I do hope it comes away cleanly or I'll be in trouble :bugeye:
Post by: awemawson on March 15, 2021, 10:42:42 AM
But I'm in the workshop to investigate high / low setting of chuck clamping on the TC 20s not cooling wax!
M81 selects 'high clamping force', M82 selects 'low clamping force' and the hydraulic pressure meter in the headstock end cupboard displays the selected pressure, and this cupboard also houses the pressure setting and selecting valves. Easy really - twiddle the pressure knob and watch the gauge!
So putting in the band sawn billet and selecting low pressure it crushed the billet :bang:
So I reset the low pressure to 'very low' (see picture) and still the chuck took another bite out of the billet - argh !
It looks like I'm going to have to think again about what to use for my trial cuts :scratch:
So I video'd the PC screen as FeatureCAM was chewing out a demonstration A2-6 'chuck back end' as a consolation prize:
Post by: tom osselton on March 15, 2021, 05:30:25 PM
Post by: awemawson on March 15, 2021, 05:40:07 PM
Post by: Sea.dog on March 16, 2021, 07:28:00 AM
Post by: awemawson on March 16, 2021, 09:18:38 AM
Was going to cast an aluminum blank today, but got distracted by discovering a rather serious data loss - when I updated computers several months back I seem to have lost all the post processors and tool cribs set up on FeatureCAM for the Beaver Lathe, Beaver Mill, and the Fanuc Tapecut Wire eroder. Quite a lot of work needed to re-create them. It seems somehow they didn't feature on the backup list but I thought I'd done a complete back up of everything including the kitchen sink :bang:
So this afternoon I need to create another Win7 machine and hope the HDD that I put in my safe has the data on it :scratch:
Post by: Sea.dog on March 17, 2021, 05:12:04 AM
Post by: MetalMagus on March 17, 2021, 08:13:20 AM
Sean
Post by: awemawson on March 17, 2021, 08:27:54 AM
. . . . BUT I've spent a couple of very frustrating days tracking down back ups on various old PC's and stashed hard drives, but NONE of them have the post processors for the Partsmaster TNC355 CNC mill or the Beaver TC20 S Siemens 820T CNC lathe. The only good news is that I think I've recovered the post processor for the Fanuc Tape Cut Model L wire eroder with it's Fanuc 6 controller (but yet to test it)
What I HAVE learnt - which is very handy - is that the Windows Backup and Restore saves it's backup as a "VHD" file which Disk Management can 'Attach' as a virtual hard disk, so that you can view and access individual files without having to restore the backup onto a machine in it's entirety .
Post by: awemawson on March 17, 2021, 11:55:33 AM
I also found an X-Build (the program that allows P-P generation) ".CNX" documentation file for the modified Siemens 810 P-P that I'd been using on the 820 on the lathe. Now the .CNX file is a form of the P-P that can be printed out and read, whereas the .CNC version is the one FeatureCAM wants. Given a .CNC file X-build can spit out a .CNX file but I can find no way of reading back in the CNX file to X-Build. OK the information IS all there and I can manually type it in but there's 10 pages of A4 . Some of it can be 'cut and pasted' but the majority is 'drop down boxes' or 'tick boxes' that need filling in.
The PP for the TNC355 in the Beaver Partsmaster CNC Mill was I'm almost certain actually a standard one for a Heidenhain TNC155 with a tool changer - I don't remember modifying it much if at all.
Had enough of it today, hopefully I'll knuckle down to it tomorrow.
(.CNX file attached but renamed .TXT to allow upload)
Post by: awemawson on March 20, 2021, 11:48:00 AM
To this end I manually turned the blank that I cast the other day and crushed with the hydraulic chuck to a 'tidy finish'. It's now ready to mount on the Beaver Partsmaster CNC Mill somehow. And that somehow is the next issue :scratch:
It turns out that my Kurt vice on the Partsmaster easily opens wide enough to take the blank but I will have to make some semi-circular wooden jaw pieces to spread the load or it will be crumbling again.
But that's a job for tomorrow
Post by: awemawson on March 21, 2021, 11:51:39 AM
Then I re-set all the tool offsets using the Heidenhain probe, and mounted up the machinable wax 'pill' in the Kurt vice with a pair of semi-circular wooden 'vice jaws' that I'd made on the bandsaw to spread the crushing load.
Getting close to cutting :ddb:
Again using the Heidenhain probe I found the dead centre of the wax pill and set is as X=0 Y=0 but set Z zero as about 50 mm ABOVE the surface to do a trial run to see if thing looked sensible.
Time to load the program. Well firstly I found that I'd lost all the coms settings for TNCServer which is the program sitting on the PC that makes files available to the TNC355 in the Partsmaster, so a bit of flapping around recreating them. Now to remember how to do it - a few false starts surrounding TNC355 file naming conventions and code line numbering and we are off - program down loading into the controller.
.. ah . hang on . program is too large to fit in memory, it needs to 'drip feed' so I set it going and we have (sensible !!!) motion from the machine hovering it's tools above the actual work level until . . . ILLEGAL PROGRAM CODE pops up on the controller screen around line 250 . . hmm ? OK then it dawns on me - it's calling a 'label' to reuse code like a subroutine, but when drip feeding the code isn't all retained in memory - you CAN'T call labels !
Program limit is 1000 line in the TNC355 - my program is 1004 long :bang:
Now I'm sure that I can do a bit of pruning - for instance cutting wax I don't want the coolant on so there's a few line to cut, but in the final run on steel coolant definitely WILL be needed.
So I'll probably split the program into two bits - but that's enough excitement for today !
(I do find using the fragile probe with it's ceramic tube probiscus rather stressy !)
Post by: awemawson on March 21, 2021, 04:41:57 PM
So very odd 'file storage' in the TNC355 - they have comparmented it into program boxes of 1000 lines each with no dynamic re-allocation of space - strange :scratch:
Post by: tom osselton on March 21, 2021, 06:36:48 PM
Post by: awemawson on March 22, 2021, 07:05:48 AM
First pass went very well, I was hovering with the workshop vacuum hoovering as the cut progressed as I don't want the wax in the machines coolant.
Second pass took ages to do not a lot until the very end. I'd had to specify a rectangular block of stock for it to cut. Although Featurecam allows for round stock I couldn't get the axis of the stock and the machining to be the same. In 3D view it looks perfect, but in plan they are misplaced - an oddity so hence rectangular stock and thus a lot of 'air cutting' before getting down to business. In the end the final cut was only about 0.5 mm and that (with all the air cutting) took 39 minutes !
I'm pleased with the results. I need to measure how accurately it's cut the 7 degree recess taper, I also need to replace the 22 mm 2 flute end mill for one with greater depth of cut - it manages but with very little margin - OK in the wax but probably pushing it in the final EN24T item.
Post by: nrml on March 22, 2021, 11:23:37 AM
Edit:
I've just gone back a few pages to look at the drawing of the spindle and I see the taper there. Sorry for the pointless question.
Post by: awemawson on March 22, 2021, 12:24:25 PM
No, the taper is a VERY relevant question as I have just realised that I mis-read the drawing, and what I understood to be a taper with limits of 7 degrees to 7 degree 30 seconds is ACTUALLY a taper of 7 degrees 7 minutes and 30 seconds (or 7.125 degrees).
I blame it on old eyes !
But this is what prototypes are for ! Imagine my chagrin if I'd gone straight to cutting that expensive EN24T billet !
I'm now wondering if Male lathe spindle nose tapers and Female chuck tapers are actually manufactured to slightly different angles. The bolting face obviously draws up tight with the taper as a register but manufacturing to get the taper an exact snug fit when the flanges are tightly together would be easier if one taper was very marginally different. Amazingly hard to find dimensioned drawings of the chuck female :scratch:
My aim today was to turn up an accurate male gauge for when I make the real thing, but other things have got in the way.
Post by: Muzzerboy on March 22, 2021, 01:31:14 PM
Do you plan to make some metal soft jaws? Presumably you will need something better than plywood for the real thing.
Post by: awemawson on March 22, 2021, 02:02:45 PM
I am hoping to turn the taper on the Beaver TC20 along with a reference bore up the middle that I can use to accurately centre it on the Beaver Partsmaster with the Hiedenhain probe as a second op. for drilling the holes and other features. I can clamp it down for that operation. I only really milled the taper for a bit of fun to see how well it came out and the answer is surprisingly well, but you can feel ridges with your nail.
For boring the taper I took delivery of a nice heavy 32 mm boring bar today with integral though coolant :ddb:
Post by: awemawson on March 24, 2021, 09:53:09 AM
If I rotate the A2-5 mounting arrangement to clear the A2-6 cap screws then there is no way to drill the joining oilway as one of the mounting holes is in the way.
But I had a flash of inspiration in the early hours this morning. The A2-5 collet chuck uses only 6 of the 12 possible mounting holes, and although the original chuck is mounted by 6 M12 cap screws arranged in three pairs there is no need for me to use this pattern as the spindle nose of the lathe is drilled and tapped for all 12 positions at 30 degree intervals.
By much faffing about, rotating drawings and standing on my head I have (I think) at long last come up with a possible solution, that is each ring of mounting holes having 6 evenly distributed members but the A2-5 ring complete with driver peg hole is rotated 45 degrees counter clockwise relative to the A2-6 ring.
It's not ideal as the holes that I will have to drill and plug that join the oil ways in the A2-6 spindle nose to the ones in the A2-5 collet chuck mount are at an odd angle and rather long at 89 mm (6 mm diameter)
I now need to lie down in a dark room with a wet cloth on my head !
Post by: nrml on March 24, 2021, 04:46:21 PM
Post by: awemawson on March 24, 2021, 05:01:20 PM
A few test drillings first I think !
Post by: awemawson on March 28, 2021, 05:49:19 AM
Next issue was an oddity in Featurecam. You can define either a 'Boss' or a 'Pocket' from diameter and depth and you can give the side a 'draft angle' - I need this draft angle to be 7 degrees 7 minutes and 30 seconds - the program takes decimal fractions of degrees, so in this case 7.125 degrees which I duly inserted. Problem is, if you return to the pocket dimensions later for editing you find that it has truncated this to 7.1 degrees. The only place in the settings where you can set the precision of variables is set to XXX.XXX and changing it makes not a jot of difference :bang:
However I discovered that there is a second way of defining the wall of a boss or pocket, that is by having a line on the drawing passing through X=0, Y=0 and at the desired angle to the Y axis, and this method SEEMS to give the desired precision, however the code it generates is MASSIVE ! Just the A2-5 boss on the adaptor generated 770 lines of code!
Anyway I wanted to test if indeed the precision was adequate before committing, and dug out a bar end of 102 mm EN8 round to use as a trial cut. All set up and program loaded to the controller it started off very well, until there was an almighty BANG, the expensive 22 mm cobalt roughing cutter shattered and the enormous power of the X axis drive carried on pressing the broken cutter mangling the work :bugeye: It had cracked the CAT40 holder and mangled the BE180 collet
.
Stupidly I had accepted all the default values of speeds and feeds without checking them, and this was the result. Carefully looking at the damage to the stock I concluded that all the damage was above the finished surfaces, so if re-centred I could possibly continue if I could find another roughing cutter (it defaults to using a roughing tool followed by a finishing tool). Well I couldn't find one, so mounted up a 22 mm cobalt end mill, very conservatively changed the feed rates and started it off. The was 14:30 yesterday - it finished cutting at 20:30 last night - 6 hours of cutting - I don't think the Partsmaster has done such a long run EVER ! Got fed up watching it so rigged a camera to watch from the house!
The way it is forming the taper is to orbit the part adjusting radius and depth in minuscule nibbles to closely approximate the angled line that I defined as the draft, and of course this gets rather tedious!
The result is surprisingly good - surface finish not as good as a turned or ground finish obviously but it seems to fit OK. I tried measuring the resulting angle with my vernier protractor but to get anything like the angle is extremely difficult on such a short length. Bluing it the contact doesn't look too bad.
I must say though, this is not the way I will be producing the tapers on the final adaptor - I will rough the blank out leaving the A2-6 'pocket' and the A2-5 'boss' parallel sided, and turn them on the lathe hopefully getting a far better finish and fit - this was just a test but even when turning I need to define the angles so probably will have to use the swept line method anyway.
Still to decide how to fixture the part - the A2-6 mounting holes go all the way through so probably I'll mill that side first and use these holes before flipping the stock for the A2-5 machining.
Post by: awemawson on April 17, 2021, 12:16:34 PM
Firstly my son was able to deliver my haul of Soft Jaws won sight unseen on eBay all the way from Chippenham. Exciting for two reasons - due to Covid this is the first time we've been together for over a year, and secondly as there were far more in the box than I had thought - turns out that they are stacked two deep :clap: Haven't had time to give them a proper inspection but I think a 'good haul'.
Secondly after he had left I was able to put the crane to it's intended use and remove the chuck to use it's female taper for making my male gauge in the next few days. It went largely uneventfully. Initially slackening the 6 massive retaining bolts, then when finger tight and the crane connected I applied a bit of lift and fully loosened the bolts. Initially there was an ominous creaking, and I realised that I hadn't withdrawn the spindle reducing sleeve that stops bars whipping in the tube. Quickly knocking it out with a bar through the chuck all was well, the chuck came away nicely, and although blooming heavy to manoeuvre it was successfully pivoted to clear the lathe enclosure and lowered onto my pump up trolley.
No excuse now not to make that taper gauge !
Post by: awemawson on April 21, 2021, 06:22:28 AM
In the event the backplate supplier hadn't got the semi finished backplate but he DID have a fully finished one all ready to go. OK I parted with one of my few remaining limbs and ordered it.
When it turned up it fitted the chuck beautifully, a lovely bit of Polish (Bison) machining, but the spindle end, although it had the correct A2-6 taper and bolt holes, it wouldn't actually engage far enough to fit. The original hydraulic chuck had a boss projecting about 9 mm whereas the adaptor boss was only 1.2 mm - argh !
Speaking to Ian at Rotorgrip who supplied the back plate and exchanging pictures it dawned on him that there was a extra shroud surrounding the spindle - removing that all was sweetness and light and it fitted like a glove. I think the shroud, which is a very heavy chunk of turned stainless steel, was probably to eliminate a swarf trap caused by the long original boss.
But I still had to stop that hydraulic oil somehow. Investigating the plumbing soon showed me that the two flexible hoses for open and close were routed to the rear of the spindle and fixed by easily removed conical fittings. As it happens I already had the proper male and female 'stop ends' for this range of fittings left over from my long gone JCB 3CX, so blanking them off and tying them up out of the way was easy.
OK chuck fitted, tightened down and a few tentative spin ups and downs performed to check it didn't fly off, then a spin test at 2000 rpm and nothing flew off - phew.
This chuck will be handy making the collet chuck adaptor, but I need to make a chuck key with a sliding bar as a standard one is fouled by the lathe tin work.
Post by: rklopp on April 21, 2021, 01:45:16 PM
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Post by: awemawson on April 21, 2021, 01:59:48 PM
Post by: awemawson on April 25, 2021, 08:25:38 AM
Anyway they came, I assembled them and have got the jaws at least vaguely sorted and they are now at least moveable as the cabinets are on castors.
So now I can get back to sorting out that chuck adaptor !
Have some boring pictures of drawers !
Post by: awemawson on April 25, 2021, 09:44:17 AM
Drawing it up this morning I found to my chagrin that if it was a large enough diameter to encompass the O ring locations, then it clashed with the locator hole on the nose so very sadly was a none starter.
Then I thought, OK, eliminate the long drilled holes by milling a deep groove between the ports that need joining, mill another groove around the first to take an O ring laid in in an oval pattern and again sealed by squashing against the spindle nose. I've been kicking that around all afternoon on Autocad, and try as I might cannot generate sufficient clearance using the current hydraulic port size of 6 mm and the current O ring thickness of 2.5 mm cord. I can possibly marginally reduce the port size, it will slow down chuck operation but would work, and I could possibly reduce the O ring cord size and stll get a seal - it's working at about 500 PSI so not enormous by hydraulic standards. I need to go away from it and cogitate as my head is spinning! :coffee:
Post by: awemawson on April 25, 2021, 10:09:43 AM
. . . .my head hurts 1
Post by: WeldingRod on April 25, 2021, 02:15:36 PM
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Post by: awemawson on April 25, 2021, 02:18:32 PM
Experimentation called for I think
Post by: WeldingRod on April 25, 2021, 05:25:00 PM
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Post by: WeldingRod on April 25, 2021, 05:26:08 PM
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Post by: awemawson on April 28, 2021, 06:30:00 AM
The original idea was to drill a very long thin hole from the outside of the adaptor, and bung it's open end with a sealed grub screw thus joining the two oil ports. I'd rejected this not liking the idea of drilling that long hole with a drill that would potentially wander all over the place.
Why not do a test ?
The feature on the adaptor that needs this 6 mm diameter hole approximately 110 mm deep is only 11.7 mm wide so not a lot of wiggle room hence my concerns. I happened to have an 'unknown specification' bit of 12 mm plate, so I shaped it to the same radius as the periphery of the adaptor so as to be a true test of starting a hole on a curve, then drilled two 6 mm holes where the two oil ports are that need joining. I don't know what the plate is, but it spoilt my new M42 bandsaw blade and I reverted to the angle grinder.
Setting it up carefully with the two holes perpendicular to a set square in the vice of the Bridgeport, I then found the centre of the plate in the Y direction using my 'ball bearing edge finder'. Setting the DRO to a Y=0 datum I then chucked up a piece of ground 6 mm bar just touching the front edge of the plate, and used it by eye to find the X location of the two previously drilled 'dummy oil ports'
Then loading a 10 mm slot drill in a collet I milled a flat on the curve of the plate as a starting point, which I then centre drilled. Moment of truth now. Chucking a standard length 6 mm drill, and with much oil and pecking for swarf clearance I took it to full depth. This was still not in danger of penetrating the oil ports. Now the REAL moment of truth, in goes the long series 6 mm drill, and this is going to have to break through into both those holes. Drills tend to grab when they break though, and I know from previous use that these particular drills are quite fragile so gently does it Andrew !
First hole reached and broken through without drama, however going deeper on towards the next oil port swarf was being pushed sideways out of the previous oil port and making alarming noises and grabbing. (The long series drill, and the depth of the plate meant that I couldn't quite totally withdraw the drill for swarf clearance without removing the drill from the chuck, which I did a few times)
OK eventually the drill passed through the second oil port and I went a few mm further just to give a good edge to the hole.
Breaking down the set up and inspecting what I've done actually showed that the drill has NOT wandered significantly and probably this will be the method that I use in the final adaptor.
(Here I was just risking breaking a relatively cheap drill and a bit of scrap plate - it will be a different matter with the actual adaptor!)
Post by: modeng200023 on April 28, 2021, 10:16:12 AM
Post by: tom osselton on April 28, 2021, 03:11:16 PM
Post by: RussellT on April 30, 2021, 05:11:04 AM
Do you think a close fitting plug in the holes would reduce the risk of breaking the drill?
Russell
Post by: awemawson on May 01, 2021, 04:18:16 AM
Post by: djc on May 01, 2021, 01:26:43 PM
...a close fitting plug in the holes...
And the very closest fitting plug possible might be to drill the long 6mm hole first, as a first operation on the raw stock, and the larger holes afterwards.
In the same vein, it might be possible to machine the perimeter of the stock so that the 6mm drill enters perpendicular to the surface, and then later on make the curve.
Post by: awemawson on May 01, 2021, 01:43:08 PM
The stock is circular so your second idea can't unfortunately be applied.
Holding this thing so that it can accurately be inverted is still defeating me - certain features on both side MUST align, but machining both sides removes any location aids. The central through hole gives me an accurate bore that I can pick up with my Heidehain probe, but the rotational positioning is a hard nut to crack. I may have to machine a flat on the side but I am trying to avoid that. There are through holes for bolting to the spindle which are an obvious feature to use but they don't exist until the second side is machined.
I've decided that I'm going to leave both the male and female tapers unmachined, then set it up in the four jaw on the manual lathe and machine the female A2-6 recess. It then can be mounted on the target spindle on the CNC lathe and the A2-5 male taper machined.
Post by: djc on May 01, 2021, 03:37:32 PM
Holding this thing so that it can accurately be inverted is still defeating me - certain features on both side MUST align, but machining both sides removes any location aids.
There must surely be space somewhere on it for two 3mm dia. through holes which can go into a sub-plate for locating dowels when you invert it. Even without a sub plate, you can indicate it back in off the dowel pins and a straight edge. Plug the holes when finished.
No space or do not want holes? Weld/glue/soft/silver solder two lugs to the outside of the stock and put the location holes in them. Remove lugs when finished on mill and before transfer to lathe.
Post by: awemawson on May 01, 2021, 03:40:17 PM
Post by: awemawson on May 02, 2021, 06:01:46 AM
I think that CNC milling the A2-6 side has to be the first operation, as it provides the widest support when inverted to machine the A2-5 side.
So I think the operations are probably:
A/ Machine the A2-6 side
B/ Machine a spoil board flat and level with suitable holes for location pins
C/ Invert the adaptor A2-5 side uppermost on the location pins, clamp down
D/ Accurately locate centre of adaptor with Heidenhain probe
E/ CNC machine the A2-5 side
F/ Set up in 4-jaw in manual lathe and machine A2-6 female taper to (already ground) test gauge
F/ Mount on CNC lathe nose and machine A2-5 male boss testing to fit on actual collet chuck that all this fuss has been about (!)
NB the EN24T stock that I am using is 170 mm - adaptor max diameter is 165 mm so not much wiggle room.
Post by: djc on May 02, 2021, 03:31:43 PM
So I think the operations are probably.../
Sorry to keep posting on this.
I hope I am not teaching you to suck eggs, but when you invert it, depending on which axis you flip it about, either 12 and 6 will remain the same and 3 and 9 will be mirrored or the other way around. Clearly the code for the second side has to match what happens to the part.
In the sequence of operations, I do not think you included the long 6mm holes. Maybe it is 'G' or later. If it is, is there anything you can do before 'G' to assist it (e.g. small witness mark for clocking/angle of drilled hole - but maybe extended pins in the larger holes that the 6mm intersects could be used on the edge of a square to set verticality)?
Post by: awemawson on May 02, 2021, 04:06:17 PM
Some time ago, and probably a page or two back up the thread, I cut a disk of thin plywood and glued prints of the A2-6 and A2-5 drawings on each side to ABSOLUTELY check that I had the correct orientations and handedness, as the original drawings that I was getting dimensions from were confusing to say the least, and I was deriving female cavities from drawings of male bosses.
(It's illustrated in reply #1008 above)
Unless I can come up with a foolproof method of being able to demount and remount the part in the correct radial orientation I fear that the long 6 mm holes will have to be done just before turning the A2-6 female taper on the manual lathe.
I cast another machinable wax billet this afternoon, and will have a full 'dry run' using it before attacking the EN24T.
I had thought that it would be easy to place a nice thick alloy spoil board under the part, drill two of the 6 holes that pass through the adaptor all the way into the spoil board and use them for locating pins, but sorting out clamping in that scenario is not straight forwards. Bolting the spoil board using the mills Tee slots is easy, but then re-clamping the inverted part that is impaled by the two locating pins becomes an issue. Clamps can only be on its sides as the entire top is being machined. Side bearing clamps will tend to dislodge it. I'm sure that there's a way but it's escaping me at the moment.
Post by: djc on May 03, 2021, 02:19:19 AM
...spoil board...
What I was afraid of with the flipping is that the operator would physically flip it in the X-axis and the CAM jockey would flip it in the Y-axis. The drawings on the part are good as long as both sides have high noon clearly marked on them.
It came to me in my sleep that you can use the T-slot as your spoil board. Make two T-nut blanks, three times the normal length. Drill and tap the first and last third of the length for grub screws to jack them into place against the slot bottom. Loctite the sides if paranoid. Location pin goes in the middle third. Relieve the underside of the middle third a little for breathing space when through drilling and reaming and for swarf clearance. Ideally, blow out drillings before reaming.
On the clamping, the old planer-era books show clamps that are like a standard milling machine strap clamp but with a pin sticking horizontally out of their nose. So the 6mm holes you need in the side of the stock could be spotted/counterbored maybe 1/4" and clamps with pins used in them. Spotting the holes slightly bigger allows wiggle room before final drilling and also gives a flat surface for the long hole to start on.
Found one: http://www.cartertools.com/spill.html
Post by: awemawson on May 03, 2021, 05:32:37 AM
Suppose I plasma cut a thick flange that will loosely encircle the billet, with hold down holes that are a loose fit to bolts into the spoil board and sidewise pressing bolts that allow the inverted billet to sit impaled by the locating pin and clamp up tight as the flange and not the billet will be moved. Then when those are tight the hold down bolts into the spoil board can be torqued down and theoretically all parties are happy.
So this morning I did a quick cad drawing and cut a flange. The sidewise clamps are the current slight issue. I am limited to a total height of 25 mm or it will be clobbered by the milling operation, the easiest option is to weld pairs of M10 nuts on - flange is 6 mm nuts are 17 mm, 6 + 17 = 23 mm so low enough.
(picture actually shows M12 nuts and bolt 6+19 = 25 so too high)
Post by: awemawson on May 03, 2021, 05:54:56 AM
I'm glad to say that they do - I'd expected to have to run a tap through the pair but although they are a bit stiff when both engaged, they are usable. No doubt the heating / cooling of the welding has drawn the two tighter together on the thread but at least it shows that the method IS possible.
Saves making 8 steel blocks to weld on !
Post by: awemawson on May 03, 2021, 01:09:20 PM
Were I doing it again I'd place the nuts closer together along the length of the bolts. As they are a standard M10 tap isn't long enough to pass through both to clean up the threads - only one was in desperate need and I had to grind back the shank of a bottoming tap for it to pass through nut 1 and clean up nut 2 !
Post by: djc on May 03, 2021, 03:07:24 PM
Allthread coupling nuts might be good to use for this as well. I have some M10 ones that are 13mm A/F so if these are common, that might help where space is short.
I think you are OK, but it is worth double checking that if the horizontal clamping bolt or lock nut ends up with its points vertical, it still meets the height restriction. Or use cap screws as the mock up.
Post by: tom osselton on May 03, 2021, 03:22:57 PM
Post by: awemawson on May 03, 2021, 03:50:28 PM
Post by: Pete. on May 03, 2021, 04:28:31 PM
I had one M10 coupler in stock and although the local Screwfix had them and was open Bank Holiday Monday we were suffering the annual London to Hastings 1000 motor bike run on the A21 outside the farm gate I didn’t fancy my chances! So I stuck to the double nut solution 😀
Lightweight :D
I went past your gate twice runing an errand to St Leonards. I would have stopped in but I was meeting someone and too pressed for time.
There were a lot of bikes though.
Post by: awemawson on May 04, 2021, 03:18:48 AM
Post by: awemawson on May 09, 2021, 06:57:40 AM
However today I did actually manage to knock up a little G code program to surface the 'spoil board' and then sort out the CNC mill to mount it and machine it. The material is some very gummy aluminium alloy that I can't seem to get a good surface on, but that's OK it isn't particularly critical so long as it is flat.
The spoil board at 300 x 330 mm is pretty much the largest object that I can mount and work on with a 50 mm face mill without running into the limits set on the machine. In deed to find the centre I would normally use the Heidenhain probe, picking up each edge, lie to it to say that it was circular, and use the centre as X=0 Y=0, but the probe can't go far enough past the edge to work, so it was an eyeball job!
I used my Mitee-Bit clamps to edge hold it as the machining had to run off all edges, but first I hand filed the 'nasties' that have accumulated over the years, removed the heavy Kurt vice, and had a detour / diversion mining in the swarf to rescue the Allen Key and Tee nut that I managed to drop in there :bang: This plate was a test sample I was given literally decades ago and it has at times had to live outside
No more playtime as it's guest check out / check in time
Post by: awemawson on May 09, 2021, 10:58:41 AM
The spoil plate needs a circle of eight M10 x 1.5 mm holes drilled and tapped to marry up with the matching circle of 15 mm holes in the billet clamp flange. So a bit of transferring co-ordinates from the flange drawing, specifying an 8.5 mm drill and M10 spiral flute tap in the tool crib, then actually mounting them and measuring their Z off sets before . . . Pressing the button :bugeye:
It's always a bit bottom clenching waiting for the machine to smash your tools to shreds and ruin your work up to date, but no - it all worked without dramas and the billet clamping flange is loosely mounted.
The M10 hold down bolts are in 15 mm holes in the flange which I hope gives me sufficient wiggle room to get things aligned when I have to invert the billet having machined one side - time only will tell !
I may cut another machinable wax as a test before doing the EN19T billet - haven't decided yet
. . . back on duty now . . .
Post by: awemawson on May 10, 2021, 04:23:26 AM
So this mornings fill in job while waiting for the postman was a nice and simple task - bore a 25 mm hole 20 mm deep accurately on the centre as previously established
Apart from checking that the loaded 22 mm slot drill WAS centre cutting, and that it's Z offset was correct - dead easy. So now if we have a power glitch etc I can get back to where we are now. Probably always sensible to incorporate some such feature in a part - even a spoil board !
Post by: awemawson on May 11, 2021, 09:40:59 AM
Today's 'simple' job was to turn a plug to go in the 25 mm hole in the spoil board incorporating a 10 mm upwards facing spigot, then fair face one face of the EN19T billet and centre drill and ream a 10 mm hole for the spigot. So the first action was to confirm that the hole in the spoil board WAS accurately 25 mm. A rough check with digital verniers lead me to question it.
So I dug out my 'Insize Digital Bore Gauge', a nice bit of kit that I've never used as someone had dismantled the probe end and not put it back together properly. A bit of intelligent 'looksee' showed that they'd fiddled with the range setting - easily corrected with a pair of miniature spanners. Checking against slip gauges showed that it was working fine .Note the picture with the gauge blocks shows it reading 4 microns undersize - that's just me not having zeroed it.
OK measure the bore in question gave me 24.894 or about 100 micron undersize - but why ?
At first I was sure that the 22 mm slot drill that I had used must be undersize as I've never had reason to question the accuracy of the Beaver Partsmater positioning system. A crude and rough check with a digital vernier seemed to confirm this but it's very difficult to get it bang on the maximum diameter of a two flute cutter - or at least I find it difficult.
So time to bring out the big guns - the PCM Toolset Tool Setter - BUT the extreme cutting edges of the two flutes at the tip were pretty well bang on at 11.007 mm and 11.020 mm.
Remember that the program orbits this 22 mm cutter to form the 25 mm bore -an undersized cutter will give an undersized bore and vice versa. If anything this cutter is very marginally oversized at 22.027 or 27 microns too fat.
So where is the error? Well I don't know, hence the rabbit hole comment, I need to find the source of this error before I proceed any further, so I think that I need to do more tests with other cutters and see what errors I get.
It can't be an undersized cutter as I've measured it
It can't be a bent spindle or holder as that would make oversized holes
The program doesn't leave a finish allowance so that's not it
Here is the program in Heidenhain conversational language
0 BEGIN PGM 14 MM
1 L Z0 R0 F15000 M91
2 TOOL CALL 10 Z S1455
3 L X0. Y0. R0 F15000 M6
4 L X-0.23 Y0. R F M3
5 L R F M8
6 L Z2.54 R F15000 M
7 L Z-20.0 R F192 M
8 L X-0.829 Y-0.781 R F384 M
9 CC X-0.074 Y-0.74
10 C X-0.15 Y-1.493 DR+ R F192 M
11 CC X0. Y0.
12 C X-0.15 Y-1.493 DR+ R M
13 CC X0. Y0.
14 C X1.5 Y0.034 DR+ R M
15 CC X0.744 Y0.017
16 C X0.842 Y0.767 DR+ R M
17 L X0.018 Y0.229 R F384 M
18 L Z25.4 R F15000 M
19 L Z0 R0 F15000 M91
20 L R F M2
21 END PGM 14 MM
So please if anyone has any suggestions I would very much like to hear them.
Post by: awemawson on May 11, 2021, 11:51:17 AM
Mounting a long travel digital plunger gauge magnetically on a set of hold down clamps firmly bolted to the bed I brought the collet of the spindle up against the plunger, over travelled a bit to compress it, and zeroed the gauge. Then I set the TNC355 controller to move 20 mm in the X axis and noted the indication - 20.002 mm and those 2 microns at the end are probably introduced error as I pressed the zero button.
So I believe that eliminates movement and scaling errors in the TNC355 controller and Beaver servo system.
So what the heck is doing it ?
Any suggestions would be very welcome !
Post by: djc on May 12, 2021, 02:01:22 AM
Use the same cutter in the same material and do it again. See if anything changes. Blue up the sides of the hole and run the program again (effectively cutting air) and see if any of the blue is removed or the hole changes diameter. It might just be deflection, which could be removed by a spring pass. Try the same hole with a 6mm cutter, with a different number of flutes. Experiment with tool offsets to see if they change anything. Try the same cutter and program on a different material (change feeds as necessary) to see if anything changes. Do a series of five holes from a cold start and see if anything changes - maybe the machine needs to warm up.
Is it climb cutting or conventional cutting on the final orbit? Is there any issue with coolant? A 22mm cutter in a 25mm hole does not leave much space for chips - maybe air blast them out as they form.
Post by: awemawson on May 12, 2021, 03:58:38 AM
I had already run the program a second time to see if a clean up cut was needed. (It is climb milling)
To eliminate cutter flexing (or maybe identify) I had decided to run the program again with the feed rates drastically reduced from the recommended levels, and went through the program first thing this morning editing them down to just 10% and had just run it when I read your comment!
The results are rather surprising (to me at least) as best as I can measure it at the moment is am getting:
Diameter in X Axis 24.914 so Delta X = 86 microns
Diameter in Y Axis 24.934 so Delta Y = 66 microns
So two odd things - firstly that material IS still being removed and secondly that there is a small discrepancy between X and Y
As the spoil plate is now fixed and centred I'm loath to dismount it for too many more experiments. I'll carry on with the machining of the adaptor as the critical dimensions will be finished machined on the lathe rather than the mill, and return to experiment when that is done.
But I will do a further run of the exceedingly slow feed rate version and see if anything changes !
(Later Note: second run of 'slow feed' program removed approx 10 microns from both X & Y diameters ending up as X=24.922 Y= 24.944)
I guess at this feed rate there is a bit of rubbing going on - cutter feels dead sharp but I don't have another 22 mm finish end mill, just roughing ones, as a substitute.
Post by: awemawson on May 13, 2021, 10:17:39 AM
So I turned up a stepped plug for the hole in the spoil plate, aiming for the mid point of the two measured diameters of 24.930 and 24.948 being 24.939 guessing that this should give me a fairly light press fit, which seems to be the case. Used a bit of unknown scrap that was an absolute joy to turn - I suspect that it's EN24T. Then I gave it a nominal 10 mm spigot 10 mm long - I aimed for 9.99 to go in a 10 mm reamed hole and actually achieved target!
Next to sort out the billet. It is a nominal 170 mm 60 mm sawn off the bar, so both faces were not necessarily parallel or square. Mounting it in the three jaw with jaws reversed I pressed it firmly home with the tailstock while tightening it - don't want that chunk leaping about the workshop - and hand spun it to estimate how far out the exposed face was. Answer, a tad over 1 mm. I skimmed it down by 1.1 mm which just left witness marks barely visible, then took a final cut of 50 microns to a fair finish.
Reversing it I hoped that the newly exposed face would be running reasonably true, and as expected I only had to take 150 microns off to achieve a fair finish loosing all the saw marks.
Then it was just a case of centre drilling, drilling out to 9.9 mm with jobbers drills, and passing a hand reamer though (supported by a tailstock centre) to finish at bang on 10 mm. The plug spigot fitted nicely. I took the precaution of drilling all the way through the billet so that were the spigot to bind I can knock it out. This plug / spigot jobby is sacrificial - it will be machined away as the adaptor is milled and I will probably have to drill and tap it to remove it finally from the spoil board!
Post by: awemawson on May 22, 2021, 12:23:12 PM
I've been holding off waiting for a 22 mm long series end cutting end mill to arrive, but I got feed up waiting, and re-jigged the program to use a 25 mm NON end cutting 6 flute end mill instead - this involved ramping down into pockets rather than plunging. I still used a 22 mm end cutting roughing mill to start off the pockets then the 25 mm for finishing.
However despite being very careful to set suitable speeds and feeds, (even to the extent of confirming the actual hardness of the billet) after a short bit of cutting disaster struck, the roughing cutter stalled the spindle and the spoil plate was pulled off the bed of the machine when I raised the spindle :bugeye:
Very close examination of the roughing cutter, which is a Sherwood Tools HSCO one, showed a tiny chip off one of the end teeth but no further damage so I really don't know why it happened. Flood cooling was washing chips away as they formed, but something jammed. It's not nice stuff to mill, EN19T, though I must say that it turned OK when I faced it.
As I had a reamed 10 mm hole in the spoil plate I was able to re-align it and re-fix it. Alignment being with two precision dowel pins, one the the spoil plate and the other in a collet, with a precision 10 mm brass collar between them. (Tap the plate about until the collar slides down!)
Having done this I was back in business, but I took the precaution of halving the feeds but I did use the same (one tooth chipped) ripper cutter - heck it has four other teeth :lol:
After that things went OK but rather slowly due to the low feed rate.
It's a compromise - too fast too high a chip load and danger of breaking, too slow and danger of rubbing and not cutting, (and this material work hardens).
Anyway, the billet is now ready to be inverted for the other side to be milled, but that's a job for another day.
Post by: modeng200023 on May 22, 2021, 12:59:28 PM
Post by: awemawson on May 22, 2021, 01:09:44 PM
Of course the actual female A2-6 taper will be 'added' (subtracted really!) on the manual lathe.
Post by: tom osselton on May 22, 2021, 05:34:26 PM
Post by: awemawson on May 23, 2021, 07:24:30 AM
So this morning I made six off 12 mm location dowels, threaded M6 axially for insertion and removal.
These dowels in theory should be below the next stage of milling and thus untouched, but although I don't know what steel they are made from (rescued shaft from a printer!) it isn't as hard as the EN19T billet so not an issue if it gets bitten. I threaded them all the way through just in case they get their heads cut off!)
Then I slackened the welded up clamping ring from the spoil plate to allow it to move a tad, and then lowered the inverted billet onto the dowels. Having added extra hold downs for the spoil plate in the form of two finger clamps, I tightened up the radial clamping set screws, and then the bolts holding the welded assembly onto the spoil plate. (Doing it in this order tends to pull the billet even more firmly downwards).
Manoeuvring the billet onto the dowels proved tricky with little to hold onto, but the handled magnets that I use to pick bits off the CNC Plasma Table proved very useful.
Then, checking everything that I could think to check I loaded up the TNC355 with the CNC code for the A2-5 side of the adaptor and pressed START. That was at 10:00 this morning - it's now coming up to 12:30 and there's an awful lot still to mill! Mind you I am running with a 50% over ride on the milling feeds after yesterdays jam.
. . . more when it finishes.
Post by: awemawson on May 23, 2021, 08:45:57 AM
Post by: Sea.dog on May 23, 2021, 10:23:16 AM
Post by: awemawson on May 23, 2021, 12:20:11 PM
At long last the second side is milled. It was not an easy journey however. At one point I was watching it about to change tools having finished a particular pocket and about to drill some holes and it picked up my delicate and expensive Heidenhain probe, and was rushing at the surface with it :bugeye:
I just managed to hit the eStop in time to save the probe, but then had to investigate why. It turned out that I'd changed the spot drill in the simulation to a 10 mm one but not specified which pocket it was in so it defaulted to the highest number - where the probe is :bang:
I edited out all the features already machined and carried on - all went well until tapping the six M10 sockets to mount the A2-5 chuck. Seems that the tap was longer than I'd specified, bottomed out and broke - my last M10 spiral flute tap :bang: Again I edited out the tapping and prior actions and re-ran the program to completion.
I will have to EDM out the tap and re-work things but I'm nearly there !
(but WHY did I start ????)
Post by: Sea.dog on May 23, 2021, 12:31:05 PM
At least you're lucky enough to have an EDM machine. How many others can say that they do?
Post by: Muzzerboy on May 23, 2021, 04:06:21 PM
So now you are set for another journey before the job is done, this time on the EDM. Nothing's easy but at least we will get some interest out of it!
Post by: awemawson on May 23, 2021, 04:12:10 PM
But in any case it was my own fault. Too long a tap in too short a hole never ends happily !
Post by: tom osselton on May 23, 2021, 06:15:04 PM
Post by: awemawson on May 24, 2021, 04:48:21 AM
Sitting my adaptor on the reverse of the original chuck I could check three at a time and I'm glad to report that they are bang on. This will allow me to temporarily mount the adaptor on the spindle to turn the outer diameter concentric to the PCD of these studs, and I can pick this diameter up on the manual lathe to get concentricity when turning the female A2-6 recess.
OK let's work out how to get that tap out. I need to make a hollow copper electrode 8.5 mm (M10 tapping size ) for the Sinker EDM machine. This is easy. But the next step isn't - that's getting it accurately set up co-axial with the existing hole. The hole is blocked by the broken stub of the tap that I will have to shear off to see the target hole. Or possibly I can make a jig using the co-ordinates used to drill the holes in the first place. All a bit of a pain in the nether regions. So . . . . .
Think outside the box - revert to car mechanics techniques - weld a nut on the broken tap and wind it out (but it IS in pretty solidly!). And even if this doesn't work it will probably shear off the top of the tap which I need anyway.
There is not quite enough room for a 10 mm nut to turn fixed to the tap and clashing with the adjacent shoulder - probably about 20 thou interference. But I reasoned that after welding the nut will be dead soft - the shoulder is the EN19T hard stuff, and we should be OK. A good spraying with anti-spatter juice, a good heavy current Mig weld and . . .
. . and sure enough - we are :clap:
Post by: pycoed on May 24, 2021, 05:38:41 AM
Post by: awemawson on May 24, 2021, 08:48:50 AM
During swarf clean up I found that one of the 16 welded on nuts had come adrift on the billet hold down plate. This probably happened when the big roughing cutter jammed cutting the first side of the chuck adaptor plate. Not particularly critical as the other nut on this set screw had held. No more heavy milling needed on the billet just drilling and tapping so no real problem.
I got the system to present me with the tap holder that still holds the stub of the broken tap, and sure enough it is of the extensible type as it should be.
When the replacement M10 spiral flute machine tap arrives I will mount the billet up again, drill the 8.5 mm holes much deeper - in fact probably all the way through, then clench my teeth and tap the holes.
Post by: awemawson on May 25, 2021, 05:51:29 AM
I bought some spare M10 spiral flute taps as they are a common size that I use
Next stage is turning tapers :thumbup:
Post by: tom osselton on May 25, 2021, 06:08:38 PM
Post by: awemawson on May 30, 2021, 09:45:41 AM
However today's objective was to remove the temporary manual chuck from the lathe spindle, bolt the embryo adaptor in reverse on the nose of the spindle (as both have nice flat and true surfaces) and turn the periphery truly concentric as an aid to mounting on the manual lathe in a concentric fashion for turning the A2-6 taper.
It didn't go well from the start - I'd thought that the weight of the manual chuck would be manageable, well it wasn't - the good thing is that it just missed my foot when it fell into the swarf collector (where I was standing) :bugeye:
OK I mounted the adaptor as planned in reverse . . . .but I've now concluded that I can't tweak it easily to be concentric for turning where it is and am going to remove it, return it to the accurate jig in the Partsmaster CNC milling machine, and use a boring head to produce an accurate concentric bore to use for centring on the manual lathe - what a pain !
Post by: awemawson on May 31, 2021, 05:00:14 AM
But what to use as a boring head - I don't have a CAT40 shanked boring head :scratch:
I've several R8 shanked ones that I use on the Bridgeport - mmm .... I wonder? Well the nominal diameter of an R8 shank is 24 mm - sit it in a 24 mm collet in a CAT40 shanked TG100 collet chuck (of which I have several) and see how a/ long the assembly is and b/ how rigid.
OK it's rather long and not brilliant for rigidity but it fits AND works. I decided to stick to low RPMs (150 rpm 43 mm diameter) and hand feed so that I had 'acoustic feedback' of how it was doing. It's not given a fantastic finish, not surprisingly, but it's OK for purpose which is merely to alow me to run a finger DTI on it on the manual lathe to ensure best concentricity. I'll see how it goes as it is.
(The nice thing about having six locating dowels on the spoil plate is that I can take it off and return it to exactly the same spot if further work is needed)
Post by: mattinker on May 31, 2021, 06:03:35 AM
Post by: awemawson on May 31, 2021, 04:11:24 PM
(A CAT40 to R8 adaptor is actually available commercially but I've not seen one for sale in the UK)
So I mounted up the embryo adaptor in the 4 jaw chuck on the Colchester Master 2500, trued up the parallel faces of the A2-5 side, reversed it and started roughing out the A2-6 taper.
I decided not to finish bore it as time was getting on and there was pressure to do other things - I need to sink the test gauge about another 5 mm into the adaptor, but a job for another day. . . .
Post by: awemawson on June 02, 2021, 11:16:13 AM
Quite fiddly getting the taper to seat with just a gnats c.... of clearance on the mounting flange and the correct depthing for the hydraulic O rings to seat was fun, but I got there in the end.
Where the O rings live in the base of the A2-6 taper the seating has been compromised by drilling the M10 tapped holes for the A2-5 chuck, so I will have to make up inserts otherwise the O rings will extrude under pressure.
The adaptor seems to seat nicely on the lathe spindle with just the right amount of 'pull in' on the flange to firmly seat the taper.
So outstanding are three things:
A/ Sort those O ring seats
B/ Turn the A2-5 taper in-situ on the lathe spindle
C/ Drill the dreaded oil way connecting holes :bugeye:
Still I'm pleased with today's progress :ddb:
Post by: mattinker on June 02, 2021, 02:30:57 PM
Ah but it worked Matthew :lol:
.
I never had any problems with solutions that work, I'm all for them!...................
Post by: tom osselton on June 02, 2021, 04:42:52 PM
Post by: russ57 on June 02, 2021, 08:30:19 PM
-russ
Post by: awemawson on June 03, 2021, 02:20:56 AM
Post by: awemawson on June 03, 2021, 04:48:41 AM
I decided to set the spindle running at low revs - 100 rpm just for a first visual check - and it was immediately obvious that something wasn't right. There was a distinct eccentricity of the outer nose where the A2-5 taper will be turned.
Now a few microns of run out at this stage is no issue as the next stage is to use the lathe to turn the next taper, but NOT something that I can see with the naked eye!
Running a feeler gauge around the interface between the spindle nose and the adaptor flange revealed an uneven gap. All 6 M12 bolts good and tight so what's happening. I thought perhaps the 'drive peg' hole wasn't deep enough and it was bottoming.
Unbolting the problem was fairly quickly found - the 6 retaining bolts were very marginally too long and had bottomed in the tapped holes in the spindle, and weren't actually pulling the flange tight onto the spindle :bang:
It was a matter of a few minutes to replace the bolts with shorter ones, and phew - all now looks fine :clap:
A big manual lathe tidy up now and I need to work out how to program the Beaver to give me the 7.125 degree taper in a progressive manner so that again I can creep up on a snug fit and yet be able to see what's happening. (The tool turret gets in the way of visual checks)
Post by: awemawson on June 03, 2021, 05:43:48 AM
And while this was happening I powered the Crocell pot up so that I could preserve the Taper Test Gauge. After all it took ages to make, might as well look after it, although frankly it's unlikely that I'll use it again.
Post by: mattinker on June 03, 2021, 06:42:47 AM
Post by: awemawson on June 04, 2021, 06:50:59 AM
First I had to return the O rings seats to their design depth of 2 mm - this had been made shallower by adjusting the taper to fit the gauge. Manual mill, hydraulic ports located by dropping a 6 mm drill into them - 1/2" end mill inserted into collet and depth adjusted accordingly.
Then I turned up some 8.5 mm rod with the tolerance on the fat size, cut a pair of 6 mm long 'pills' to act as inserts, popped them in with Loctite 601 high strength retainer and adjusted their depth with screws coming in from the A2-6 side.
The insert very slightly impinges on the recess for the O ring but I don't think that it is of any consequence (famous last words!)
Can't do much more until the 601 has cured - probably just as well as I have duties with cottage guests arriving.
Post by: awemawson on June 04, 2021, 09:18:48 AM
Meanwhile I needed to work out what tool to use to be able to 'get at' the A2-5 taper to machine it. It's well inside the protected zone being 'behind the chuck' so to avoid mucking about with the settings for the 'machining envelope' I'd got hold of a humongous through coolant boring bar with a 32 mm shank. Mounting it up I proved that I could reach all aspects of the taper so next thing to check is the through coolant.
The bar is hollow with a small passageway for coolant. The holder accommodates this and also external coolant through a pipe mounted in a ball socket that can be locked in any position by tightening a countersunk cap head screw that bears on the ball. To redirect the flow down the hollow all I have done is to rotate the ball so that the hole for the pipe is at 90 degrees to where it should be to block the port, it's not 100% but adequate for what I'm doing.
The bar is really sticking out too far but I need it's length to to maintain visibility and I don't want to cut it down as that is the only way of reducing it's projection. (Shorter bar = less chatter but it's pretty solid!)
So two thing left to do, both of which I'm nervous of:
A/ programming the taper so that I can advance it in nibbles for test fits
B/ Drilling those long linking holes to couple the hydraulic ports
Post by: awemawson on June 06, 2021, 06:23:15 AM
So I re-fitted the manual 3 jaw chuck to the CNC lathe, and mounted the 100 mm bar end of EN8 in the manual lathe to reduce 14.31 mm of it to 86 mm.
Oh -what's happened to my nice Newall DRO - none of the value setting buttons would work although the axis values displayed and were updated with movement :bugeye:
I've had this Newall Topaz two axis DRO on my Colchester for about 20 years - they had a deal whereby the price was greatly reduced AND a man came to fit it, so I parted with quite a wad of cash but it has been excellent apart from one problem that started just after warranty expired: The 'Set Zero' buttons for X & Z didn't work but I could still set zero by entering '0' on the appropriate axis - just an extra key push. Well now I couldn't even do that :bang:
I do have a spare 3 axis head but would rather not use it - time to pull the 2 axis one apart taking great care not to tear ribbon cables. Well as expected there's not much that you can do inside. There is a receiver board for the transducers, a power supply, a main logic board, and sandwiched below the membrane keyboard with a ribbon cable connection. Very easy to inflict fatal damage in these things if you are not very careful.
Now I was strongly suspicious of the membrane keyboard itself, but it was bonded to the front panel and removing it wasn't feasible. OK what CAN you do - well the keyboard connector is a ribbon plug in - clean it, put a bit of switch contact cleaner on it and pray to Mecca.
To my HUGE surprise not only was the fault that developed today cleared, but the one I've been putting up with for decades - it WORKS :ddb:
OK great excitement but get on with some machining . . . the 100 mm bar end was quickly reduced to 86 mm for 14.31 mm of it's length producing some impressive purple swarf (3 mm DOC at 770 RPM) - don't try and handle this sort of swarf - it will rapidly cut you to the bone. I use long snipe nose pliers.
Bar end now mounted in the CNC lathe and I have an embryo program written to cut the taper but it needs a bit more tweaking when there are less distractions around.
Post by: BillTodd on June 06, 2021, 03:48:35 PM
Newall dont sell the membrane separately (may not even sell those any more!) .
Bill
Post by: awemawson on June 06, 2021, 03:56:33 PM
Post by: awemawson on June 07, 2021, 06:24:24 AM
This was just to try out feeds and speeds and check for vibration on the rather over long boring bar. As I feared it is excessive. I ramped up and down the feed rates and RPM but cannot get a 'sweet spot'
i fear that I will have to revert to more conventional tooling - I was trying the boring bar to give better visual access but it looks like it's a no no.
Despite the video giving the impression that the work is rotating in the wrong direction, it is in fact rotating clockwise looking at the chuck, cutting force being down onto the insert (tool behind the work).
Post by: awemawson on June 07, 2021, 07:24:29 AM
Post by: djc on June 07, 2021, 02:16:34 PM
The one in the 'down' direction could be a 5mm plate with a triangle under it, bearing on some other part of the machine. Tool just sits on top of it.
The one in the 'back' direction might need a little more thinking about.
If you wanted to persevere with the boring bar, a big, hollow sleeve loctited to it with a square end bearing against the toolholder would help (eccentrically bored to put the extra material in the most useful place).
Post by: awemawson on June 07, 2021, 03:10:38 PM
If I'm desperate I can cut the tool shank to shorten it (but check first that the proposed length still reaches without entering the forbidden zone) but I don't want to really as that's a relatively new (and not cheap) tool.
Post by: Pete W. on June 08, 2021, 09:49:46 AM
Post by: awemawson on June 08, 2021, 11:08:59 AM
If it DD happen due to a combination of several faulty circumstances it could be disastrous. particularly with the original chuck weighing over 47 kg and possibly spinning at 3500 rpm - that's a whole lot of energy stored :bugeye:
Post by: AdeV on June 10, 2021, 03:16:12 AM
I've got a 32mm diameter one here which I've never used, and never will (it's far too big for my lathe), which I'd be happy to send to you... you can cut it down to the length you need.. The only thing is, it doesn't have through coolant.
Post by: awemawson on June 10, 2021, 04:09:05 AM
The problem with that bar is the way it is mounted with so much 'stick out'. As it mounts perpendicular to the tool disk it's total length has to be exposed with only the depth of the holder contributing to rigidity. I could cut it much shorter but that seems a scandalous waste.
Using the conventional 25 mm square lathe tool with carbide inserts fully sticking out the finish is actually quite acceptable, however I have decided to cut it in half reducing stick out and have ordered a replacement to salve my conscience as it will be a usefully equipped tool holder for the future.
Post by: awemawson on June 17, 2021, 12:05:45 PM
In practise I've been tied up with significant animal care issues this week as the other half has been away, so my life has been sheep, chicken and green house and polytunnel watering so probably couldn't have resumed work anyway until today. Mind you this HAS meant that the dogs and I can be in the best sitting room without risk of attack :clap:
So - cut the blooming thing - well first careful measurement showed that I could only truncate it by 30 mm and still reach the work piece without the turret entering the protected zone, but 30 mm can be quite significant in terms of chatter.
Hacksaw job :scratch: Well just as well my hardness tester was to hand - measuring 415 Brinell it's a job for the angry grinder. Severed and tidied up on the disk sander it is now in the turret awaiting it's Z & X offset being measured. Hopefully I can do this tomorrow between guests checking out (two sets) and guests checking in (another two sets).
. . . only a little step forwards but at least it IS forwards !
Post by: awemawson on June 18, 2021, 05:02:24 AM
I had overlooked the fact that the adaptor is only 45 mm thick off the mounting flange whereas the temporary 3 jaw manual chuck my test piece is mounted in is considerably thicker at about 140 mm to the relevant bit of the work piece meaning that far from shortening the tool I need to EXTEND it 76 mm :bang:
This of course is why initially I'd used the fat boring bar but rejected it on vibration ground
. . . . time for a rethink - I only need to turn about a 15 mm length of taper but it has to be 'dead nuts on' as far as concentricity and angle :bang:
Post by: hermetic on June 18, 2021, 07:06:48 AM
Post by: awemawson on June 18, 2021, 08:07:21 AM
I've taken up Ade on his very kind offer of a 32 mm boring bar that I can trim to length so hopefully I can pull something out of the bag.
I did actually investigate how to reset the 'Z Travel Software Limit', but it turns out that what is reported as exceeding the software limit is in fact a hardware travel limit set by cams and a microswitch. I could move them but I think extending Z travel by 75 mm past the designers intention is pushing it too far - I don't know what else such as ball nuts and covers and guides might suffer.
Post by: Henning on June 19, 2021, 04:17:06 AM
Anyways, quite enjoying the saga, and all the detours. Keep up the great work
Post by: awemawson on June 19, 2021, 08:15:44 AM
Today I decided to tackle the setting up to drill those rather long oil galleries. The ports to join are on either face of the adaptor and need to be aligned precisely vertically. I reasoned that by inserting a 6 mm bar into each port I could somehow rotate the adaptor while mounted on an angle plate until they were aligned, then worry about lateral positioning.
(I need to drill 6 mm galleries through a land that is only 9.8 mm wide for practically the fully length of a long series drill)
It rapidly became obvious that having the adaptor held on the angle plate with a central bolt wasn't going to work. Adjustment in small increments was by rotation of the adaptor, BUT the centre of rotation kept changing as the bolt was a very loose fit.
What I needed was a close fitting pivot to rotate the adaptor on in a more controlled manner. (I'd considered a vertically mounted rotary table but one of the ports would have been obscured by the table).
Hunting through the scrap box, to my delight I found an old tractor hitch pin that was absolutely precisely the right diameter and it also was centrally drilled for a grease way which would aid drilling and tapping to put studs in the ends. Ah yes - BUT it's as hard as a witches titty. I did cut the bruised end off with an angle grinder but facing it on the lathe with carbide tooling was hard work and tapping it with HSS taps would court disaster. OK shove it in the forge and soften it ! Well common sense prevailed - it is full of grease in the central hole so it'll smoke the place out, and the fire will mar the currently acceptable finish.
Don't be a cheap skate I said to myself as I cut 100 mm off the end of my rapidly reducing stock of 50 mm round EN8. I turned it to a close fit for the bore of the adaptor (43.450 mm) and drilled and tapped both ends M12 having parted it of at 57 mm long to let it clamp in the 60 mm deep adaptor bore.
This pivot piece then bolted onto the face of the angle plate allowing smooth rotation with the centre of rotation staying put, unlike previously.
Next stage - do the adjustment, but I've been called away for the present.
Post by: awemawson on June 19, 2021, 11:39:40 AM
I had to modify the angle plate to allow the 6 mm bar into the lower hydraulic port, but that was just a quick trim with a carbide burr in the die grinder.
So having the two ports hopefully 'dead nuts' in alignment vertically, I picked up the edge of the flange with my 22 mm bearing edge finder, popped over (11 + 4.9) mm and set the X zero and was ready for drilling.
First up, a 6 mm end mill to start the hole as starting a drill on a curve would be impossible. Then when down about 20 mm, with copious amounts of lubrication and chip withdrawal I swapped over to a jobber length HSS Cobalt drill and gently took it to full depth. I continued to use the collet as it gave much more headroom than a chuck.
Then for the 'Long Series' as this is a deep hole. I only have HSS not HSS Cobalt - initially it went fine but then DISASTER my worse fears - the drill broke.
So I have 50 mm of 6 mm HSS drill broken off with it's tip about 60 mm from the surface - stuck firmly and not going anywhere :bang:
Fortunately it looks that there is enough clear hole to give me an accurate start for an EDM electrode if I can find some 6 mm thin wall brass tube, and it's already mounted on the angle plate in the correct attitude.
. . . .oh joy . . .
Post by: awemawson on June 19, 2021, 12:47:07 PM
Daren't leave it alone so it may be a late supper.
Post by: awemawson on June 20, 2021, 07:12:21 AM
I'd decided to finish the hole with EDM rather than drilling, as the surface of an EDM'd part has been subjected to intense heat at a microscopic level, and with this alloy steel could well cause hardening that would break another drill.
When it finally broke through into the lower port I breathed a large sigh of relief, as not only was this particular disaster overcome, but the holes actually lined up :clap:
Next job was to re-mount it on the milling machine, drill the upper port slightly deeper (5 mm) to intersect the long hole and then re-mount it to open up the top of the long galley to 6.8 mm and tap M8 to receive a grub screw to blank it off.
I went very gingerly and used an HSS Cobalt drill. Started the tap in the mill to guarantee verticallity and finished it by hand.
So after a lot of faffing about that is one of the two oil galleries created. I have ordered up HSS cobalt 6 mm long series drills for the next one, and also some 6 mm thin wall brass tube in case I have another disaster!
(I might tidy that rather ragged tapped hole up with an end mill)
Post by: hermetic on June 20, 2021, 07:38:03 AM
Post by: mattinker on June 20, 2021, 10:38:22 AM
Cheers, Matthew
Post by: awemawson on June 20, 2021, 10:48:33 AM
So after lunch I cleaned up the entry to the first oil gallery with a suitably sized countersink, and then re-set the mounting to present the other two oil ports vertically above each other. I'm glad I went to the trouble of making that pivot, it makes life so much easier!
Then it was a case of 6 mm end mill to give a start for the drill on the curved surface, and drill it out to 52 mm deep with a short series HSS Cobalt drill.
The hole needs to be about 110 mm deep finally but I've gone as far as a short series is happy, and that with masses of ups and downs for chip clearance and adding lubrication. Long series cobalt drill is due by Wednesday and although I have several plain HSS ones, in light of the previous experience I'll wait until it comes!
Post by: awemawson on June 21, 2021, 02:19:53 PM
Same 32 mm diameter as mine but somewhat longer - glad to find that I have suitable tips in my stash of carbide :thumbup:
I gave it a bit of a clean up on the wire wheel and mounted it in a 32 mm VDI40 socket holder - note the the socket supports the bar for 85 mm and that I calculate that I need about 200 mm total length so I can shorten this one by about 175 mm.
Just for a laugh I mounted it up 'uncut', and naturally it vibrates like a goodun - we'll see what happens when shortened. If it still vibrates I'm going to surround it by a cast lead jacket, but that's for tomorrow.
Post by: awemawson on June 22, 2021, 07:00:46 AM
I must say that these M42 8% Cobalt Osborn drills make short work of this hard alloy steel.
Same process as before culminating in tapping for an 8 mm grub screw as a stopper and cleaning up with a countersink. It is a huge relief to have finished these long holes :ddb:
So what's left :scratch:
Just the taper profile for the A2-5 chuck to fit on, and also make a driving peg for it.
Post by: awemawson on June 22, 2021, 09:23:36 AM
Very carefully working out how long to leave it I then did the deed, and cleaned it up on the disk sander to at least look presentable. Mounting the shortened tool in the turret it at least looks less ridiculous than before it was cut, but how will it perform :scratch:
. . . Well the answer is with FAR less vibration - it might actually be satisfactory. I've only tried turning under what is called 'Overstore' on this controller, where you can set the spindle rotating at your desired speed and direction, then use the manual jog or handwheel to control Z and X
Have other duties this afternoon so next time I'll try under program control and see how good a finish I can achieve.
Post by: WeldingRod on June 22, 2021, 02:31:48 PM
Just dreamin' ;-)
Sent from my SM-G892A using Tapatalk
Post by: awemawson on June 23, 2021, 04:43:02 AM
Sweet spot seems to be 1500 rpm with 25 micron DOC - not using coolant so the whispy swarf glows like steel wool falling onto battery terminals!
Finish should improve with coolant. Note that this taper is the correct 7.125 degrees wall angle but smaller diameter than the actual adaptor nose as this bit of EN8 has been turned a few times !
Post by: awemawson on June 23, 2021, 06:24:59 AM
After all those dramatic glowing bits of swarf WERE a clue :ddb:
No point in accurate tool setting until I get this feature sorted - probably just far too high a surface speed added to no coolant.
I tried photographing the tip on my Baty Shadowgraph, but the image was swamped by the light - the only way I could get a result was to make a little video moving round the tip shape - hopefully this will convey what I can see with my eye :scratch:
First the worn tip:
Then a virgin tip:
Post by: awemawson on June 23, 2021, 01:09:29 PM
Doing a test turn at 600 RPM with a fresh tip the finish was not as good as before but acceptable. I suspect that previously it was being burnished by the worn tip.
Hopefully finish will improve when I rig up a coolant pipe for this tool.
Even after this minor test there was detectable wear on the tip - I wish I knew what grade of carbide it is. I do have some TPKN 16 03 PP tips in P40 carbide that will fit this bar, though instead of a tip radius they have two small facets approximating a radius - I may try those tomorrow!
Post by: awemawson on June 23, 2021, 03:50:20 PM
So out to the workshop and I swapped the insert for a TPKN 1603PPTR which is the one with the odd two facets rather than a radius.
It actually gave a pretty good, and certainly acceptable, surface finish on this test piece of EN8 steel at 700 RPM. I just need to work out graphically if there are any implications for the male taper nose profile where it protrudes from the base metal - it may be within the chamfer of the chuck, but I need to check that they won't clash.
(The value "BS" in the picture is 1.47 mm)
Post by: jiihoo on June 24, 2021, 07:21:44 AM
Post by: awemawson on June 24, 2021, 10:12:49 AM
Today's job was to see if there was any way to cut an undercut at the root of the taper where it meets the body of the adaptor. This is to prevent any problems mating with the chuck body. Chuck body has a very small (just over 1 mm) 45 degree facet here but with the tips I have I can't get the root radius small enough to sit in that facet.
Normally I'd just use a parting tool or diamond tipped tool to form a groove at the root, but here I am working out side of the envelope where normal tools can reach.
Trying to push the TPKN 1603PPTR to it's limits to make a groove there I ended up with a nasty crash, pulling the EN8 bar end out of the chuck :bugeye: Lucky this is an experimental test piece! Tidying it up on the manual lathe I got it back to a state where I could experiment cutting ever smaller tapers I've come to the conclusion the with a TPUN160304 tip (ie 0.4 mm tip radius) I should be able to get away with it - I have TPUN160308 tips but in a carbide grade suited to aluminium - so too soft and too large a radius.
TPUN160304 tips on order in P40 grade (steel and alloy steels)
All a bit of a pain but this is why I'm making numerous experiments before working on the adaptor itself - don't want to wreck that at this stage
Post by: nrml on June 24, 2021, 03:17:27 PM
Post by: awemawson on June 24, 2021, 04:10:44 PM
The face where the under cut should be has to contact the relevant bit of the chuck absolutely and precisely when the tapers close together.
As the taper wont close without the under cut I cannot be sure the sizes are right, and dismounting it would be counter productive concentricity wise,
I had already thought that I could 'half machine' the taper, mount it on the manual lathe for undercutting, remount it on the CNC and finish the taper but it's fraught with introduced inaccuracies
. . . .it's all a blooming palaver !
Post by: nrml on June 24, 2021, 04:15:10 PM
Post by: awemawson on June 24, 2021, 04:47:48 PM
Post by: modeng200023 on June 25, 2021, 05:26:17 AM
No doubt you have this in mind but I've not seen temperature mentioned in this discussion.
John
Post by: awemawson on June 25, 2021, 05:39:35 AM
I think the major issue is to get the taper to seat leaving just a nat's thing-a-me-bob of clearance between the chuck and it's flange, so when the bolts are torqued down the taper is pulled well home. The internal mating faces where the hydraulic ports join is marginally less critical due to the aforementioned O rings giving a bit of tolerance.
I'm pleased to say with the larger taper of the 'adaptor to lathe spindle interface', once bolted up, and then unbolted, it took a few persuasive blows from a large rubber dead blow hammer to unseat it and it's that sort of fit I want to achieve with the 'adaptor to collet chuck interface'
(A self releasing taper needs to be 16 degrees or greater - this one is 2 x 7.125 = 14.25 degrees so just on the self holding side of the line!)
Post by: awemawson on June 25, 2021, 09:05:21 AM
. . . I think that it will but would welcome comments as usual.
I measured the chuck chamfer as reasonably accurately as I could visually at 1.5 mm, and assumed (!) that it was evenly distributed either side of the centre line of the chuck face and taper wall, which are at 97.125 degrees to each other, and drew it up, large scale, in Autocad. It seems to say I'm OK but as I say comments are welcomed!
Post by: djc on June 25, 2021, 01:39:35 PM
If so, is there any reason not to modify (increase) the chamfer on the chuck if the peskiness proves to be obstinate?
Post by: awemawson on June 25, 2021, 05:13:18 PM
I'm hoping such activity will not be needed, but yes this is to mount a specific internally hydraulically operated collet chuck of A2-5 mounting specification on a spindle made for A2-6 devices with the same internally operated hydraulic mechanism.
(most CNC hydraulic chucks use an external hydraulic co-axial cylinder mounted round the spindle bore tube - not this one!)
Post by: awemawson on June 26, 2021, 05:01:59 AM
They are TPUN 160304 S6-P40 , so the correct grade of carbide as well as correct tip radius which has made a noticeable difference to the surface finish as well as to the corner radius.
I now need to be brave and mount up the actual adaptor and work on that :bugeye:
Post by: mattinker on June 26, 2021, 06:21:14 AM
All the best, Matthew
Post by: awemawson on June 26, 2021, 11:14:30 AM
Initially this greatly puzzled me - I was using very conservative in feeds, but then it dawned on me - this boring bar mounts it's insert with ZERO back clearance behind the cutting edge. Usually there is a good 5 or 7 degree, so as the insert is fed in radially if there is ANY vibration it ends up taking a broader and broader cut. The evidence was there from the last dig in. If you look back to the picture of the damage look how broad the eventual chip was once the tool had dug in :bang:
Now I cannot afford to risk this when turning the actual adaptor - I've invested too many hours in it, so I've decided to change horses mid race. I've found a 32 mm boring bar of suitable length that takes VCMT 1604004 tips with a 35 degree diamond profile mounted to give very adequate clearances so I'll just have to twiddle my thumbs until it arrives.
. . . such is life . . .
Post by: awemawson on June 30, 2021, 06:34:39 AM
I turned the blank to the major diameter and length of the taper, then marker blued the parallel blank.
The program progressively forms the taper, reducing diameter by 25 microns each pass. As the taper forms the blue area decreases showing progress. In the final part it will be very securely bolted to the spindle allowing me to make test fits at stages without disturbing it. Here the blank is only in a manual 3 jaw and the weight of the collet chuck would undoubtedly move it in the jaws.
The finish with these tips is not as good as the previous one being slightly 'torn' so I need to experiment with speeds and feeds again.
Post by: Sea.dog on June 30, 2021, 06:49:25 AM
Post by: mattinker on June 30, 2021, 08:43:51 AM
Might it not have bee easier to grind some relief on the previous insert? OK, you sacrifice an insert, but you get the job done and with a better finish.
Inserts are sacrificial by nature.........................
Post by: awemawson on June 30, 2021, 08:46:30 AM
I've just re-run it with the feeds somewhat reduced and the finish is very acceptable. It'll all change again when I mount the adaptor, as that's EN19T not EN8 !
Post by: awemawson on June 30, 2021, 12:31:53 PM
This afternoon I mounted up the part finished adapter and crept up on the final size. I may still have to do a bit of adjustment but it's pretty well bang on with the rear flange and the taper closing simultaneously. I may have to trim a tiddly bit off the flange to make sure the mounting bolts pull the taper home for the last tiny bit - not sure.
I used a 'chuck catcher' (just a bit of gas pipe pushed up the spout) to save my toes, and it worked quite well :thumbup:
A slightly stressful operation with people bursting into the workshop at just the wrong moment but I got there in the end :bang:
. . . enough for today . . . . I still need to check concentricity and check the hydraulic side of things but that's for tomorrow
Post by: Sea.dog on June 30, 2021, 03:51:36 PM
Post by: awemawson on June 30, 2021, 04:09:45 PM
Now - why did I want a collet chuck ? Oh yes, because it floated by on eBay :lol:
Post by: tom osselton on June 30, 2021, 05:30:16 PM
Post by: mattinker on July 01, 2021, 06:52:58 AM
Post by: RussellT on July 01, 2021, 07:08:35 AM
Post by: awemawson on July 01, 2021, 07:15:55 AM
Firstly I put a DTI on the internal operating taper of the closer and was appalled at the run out:
Then I realised of course that the taper slides in and out using the internal hydraulics - there is no collet in place - not even the front plate that retains the collets so until I've sorted the hydraulics that's not going to be a fair test.
But what about the body of the collet chuck - it was probably made to be pretty true though not the primary accuracy element. Sure enough it was dramatically better than that internal taper. However I'm still not convinced that the mounting taper is seated fully into the chuck as there should be a microscopic gap between the rear of the chuck and the mounting flange, and there isn't.
So I dismounted the chuck to skim a tad off the flange and measure the concentricity of the A2-5 mounting taper while it was off. Dead nuts ON as it should be having been turned on the lathe.
Measuring the chuck body run out it was marginally reduced but not zero, but there again I've probably not skimmed enough off the flange as I still can't see a gap at all
So it's still a work in progress !
Post by: awemawson on July 01, 2021, 09:48:11 AM
So suitable collet fitted and 10 mm ground pin inserted.
I'm afraid the news is not good - still showing 100 micron / (4 thou) run out
Post by: awemawson on July 03, 2021, 11:52:39 AM
I needed to make and fit a driving peg which meant taking the adapter off the spindle, but first I did a 'sanity check' on the taper runout -zero as before. OK then I removed the adaptor and with it on the bench blued it's taper with a light smear of hi-spot and checked the taper fit. Very nice surface contact was revealed. Then I made up the actual drive dog - 15.9 mm mild steel drilled 6.1 mm and countersunk for an M6 CSK screw. I also made a drilling jig from the same 15.9 mm bar drilled 5.0 mm to help align the drilled and tapped hole that I needed to make in the drive dog recess.
Now either this adapter is more flexible than I would have thought or some other phenomenon is occurring. With the chuck sitting on the adapter and bolted hand tight I can measure a gap of 30 microns between the flange and the chuck body. If I tighten the six M10 screws murder tight (as they should be) it closes the gap so not only will the feeler not enter but I can't see light through the gap. So the taper has been engaged a full 30 microns further 'on'.
I re-mounted the adapter - checked the taper run out which pleasingly was still zero and skimmed a further 30 microns off the flange and remounted the chuck. Same thing, if bolts hand tight a gap, but if driven fully tight then the gap closes to zero.
Now I am assuming that the major concentricity alignment is the actual taper faces, the purpose of the flange and bolts being to hold the taper in engagement and if it 'bottoms out' this is a good thing for rigidity and load capacity. Well it certainly bottoms out when torqued up!
Chuck body run out was unaffected by these shenanigans and I didn't try fitting a collet as there is no reason to suppose it will have magically improved.
I think then that the next action is to whip off the chuck and adapter, fit the hydraulics O ring seals and oil way bungs and try it 'for real' I may dismantle and clean the chuck in this process but it is crawling with springs and pistons and seals and goodness knows what else.
Post by: awemawson on July 03, 2021, 12:17:39 PM
So I steamed the machine up again and this time ran my DTI on the quasi-backplate. Well I never - the chuck backplate has zero runout so maybe the chuck body to backplate interface is the problem ! :ddb:
Now when I got this chuck and was thrashing about trying to find a way of mounting it, I managed to have a conversation with one of the engineering Directors of the late Balding Engineering company that made the beaver, and he said that some of the collet chucks had detachable true backplates. Well as an investigation I pulled it apart when he was on the phone, found that it was not a true back plate and put it back together - all one handed while holding the 'phone. Did I possibly not get the rotational position correct and is this the issue?
Hopefully a more controlled dismantling and cleaning will reveal all :scratch:
Meanwhile see the proof in this video :
Post by: awemawson on July 04, 2021, 07:09:49 AM
(There is always the tendency to suspect your own work first I suppose!)
Thus my plan today is to once more remove the chuck AND the adaptor, and ready the adaptor for hydraulics. This involves loctiting grub screws in the oil galleries to block them off after a thorough cleaning, and refit the adaptor with O rings.
I'm pleased to say that both tapers were the very devil to separate so they must be good fits :ddb:
Once the adaptor was back on the spindle I again checked its runout just in case the O rings were misplaced or too fat etc, but glad to say all was well
Post by: awemawson on July 04, 2021, 07:23:48 AM
The body is in two halves held together with nine cap head screws. Gingerly undoing them the two parts start to separate by the pressure of the internal springs so I carefully marked the current orientation in case it had to either go back as was or rotated depending on what I find.
Well happily (I suppose!) there are three tapped hole to force the two halves apart if it gets stuck, and I could distinctly see the ghost of the holes in the flange that the screws would bear on, and they are orientated as they should be. So no, I didn't cock up the orientation.
Further proof was shown by a tiny locator hole for a pin in both halves with an equally tiny O ring to retain the pin, however the pin was missing !
So I carefully cleaned up the mating surfaces, removed a minor amount of debris and put it back together exactly as it was, obviously as assembled in the factory, as I thought there was little point in ringing the changes having found the pin thingy.
All back together, and refitted - needless to say the run out is still there but this is to be expected
So next the big leap: Re-couple the hydraulic lines that I had had to blank off at the far end of the spindle, and see if the chuck actually works or whether it spews hydraulic oil everywhere :bugeye:
Hoo-blooming-ray it actually works. OK there is a run out issue, but perhaps my expectations of a thirty year old heavily used chuck are too high :scratch:
Post by: carlquib on July 04, 2021, 11:05:43 AM
Sent from my SM-N976U using Tapatalk
Post by: awemawson on July 04, 2021, 12:25:32 PM
Just 'cos I could, I swapped the 10 mm collet for a 25 mm collet, and guess what - run out reduced to 20 microns :clap:
I reckon someone has whacked the 10 mm one that I was using, though it looks OK'ish
Post by: AdeV on July 04, 2021, 03:08:37 PM
Nice work Andrew!
It's hard to say from the video, but is that piece in the last one a bit of raw bar stock? How about turning an oversized piece to fit the collet (possibly on another lathe, unless the collets are easy to swap), turn the oversized end true, then flip it end-for-end & see what the runout is then? I'm just wondering if your raw bar (if that's what it is) is not actually perfectly round.
Post by: awemawson on July 04, 2021, 03:19:12 PM
When I get a bit of time i'll dismantle them and give them a clean up. They are only held together by an encircling spring clip, with rubber bits between the sections.
Post by: AdeV on July 04, 2021, 04:41:21 PM
Post by: awemawson on July 04, 2021, 05:19:22 PM
Post by: AdeV on July 05, 2021, 02:41:26 AM
Time to figure out a program to make your own?! :smart:
Post by: awemawson on July 05, 2021, 04:45:19 AM
It was suggested quite correctly by Ade that the surface of the previous test bar could be the cause or at least contributing to the observed run out of the collet chuck. After all it was just a bit of MS bar stock.
So this morning I mounted up a piece of 30 mm bar that I had parallel ground to a good finish in the J&S 1300 cylindrical grinder and measured it's run out. It's a different collet of course being a different diameter but this probably is typical of what the chuck can achieve at the moment with the rather old collets that I have, and it's state of wear. Perhaps 15 microns run out.
Now I reckon that most of this is going to be in the taper that the collet is pushed into to close, so I'm scratching my head how I can possible grind or lap this in situ on the lathe.
As always, suggestions would be welcomed.
Post by: awemawson on July 05, 2021, 09:38:11 AM
Am I chasing ghosts - it seems a lot of run out to me.
Post by: awemawson on July 05, 2021, 10:14:43 AM
Post by: awemawson on July 28, 2021, 03:34:24 PM
Going to the machine to review tooling, and powering it up there were odd and unfamiliar humming noises and the machine wouldn't go 'Ready' :bang:
Now over the last few days we have had masses of rain and some very significant lightning - though not (I'd thought) very close.
So far I've spent a couple of days on the diagnosis trail and found a blown up memory card. Fortunately I had a spare, and now at least the controller is going ready.
At this point I've been able to load back ups of the PLC program and the other gubbins - in fact I've been through the process FIVE TIMES :bang:
However, although I can 'reference' the machine, jog in X & Z, rotate the tool turret and select a tool, I cannot start the main spindle. You may recall this is driven by a vast Maudsley DC motor by a KTK DC drive and a propriety field current source. If I program a modest spindle speed (say 100 rpm but it doesn't seem to matter what) there is a slight increase in hum level but no rotation, and after a few seconds it errors with 'spindle speed too high' !
Putting a DC clamp meter on the field drive it's passing a reasonable 5.9 amps. Transferring it (On AC) to the feed to the KTK driver for the motor, it briefly is drawing about 40 amps (at 120 V 3 phase) before erroring.
The othere oddity is that one of the files that's been re-loaded (several times into RAM) maps PLC error and comment numbers to text, but despite this the controller is reporting the number and not the cross referenced scrap of text.
Now this controller has bits of ROM and bits of RAM in several places and I've never satisfactorily managed to map what is supposed to be where - the manuals are as vague as a salesman's promise!
The spare could be faulty of course and explain both issues, but I seem to remember previously using it. There is another for sale on eBay at a reasonable price, but the postage and customs duties from the US are crippling :
https://www.ebay.co.uk/itm/130842358746?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
(This is one of the cards that were destroyed before I got the machine by oozing lithium battery juice, and indeed is the same as the card that was the source of he leak!)
. . . decisions . . . decisions :scratch:
Post by: Sea.dog on July 28, 2021, 03:55:20 PM
Post by: tom osselton on July 28, 2021, 05:29:13 PM
Post by: awemawson on July 29, 2021, 12:48:17 PM
Things have gone from bad to worse - I've ended up with a blank screen and no activity :bang:
I had noticed an oddity. If I manually turned the spindle, even a degree, it immediately gave the spindle over speed error message. Now the spindle is monitored by a 'measuring card' that takes input from the optical disk - I had a spare so swapped it - no difference. Now this card talks to the CPU card - I had a spare (in fact the original that came with the machine - it's frame is slightly corroded but I'm sure that I've previously proved it OK. BUT swapping it into the machine - BLANK SCREEN. Putting back the one I took out but still BLANK SCREEN :bang:
The video system is a pair of cards - a clever one and a bank of memory - no spares. :( I reasoned that it was possible that the display itself may have died. Just putting in these two cards I got a random display, proving that at least the CRT was good (I'd tried to see the cathode filament glowing but couldn't)
The power supply is slightly suspect. it gives several rails none of which are accessible to monitor except the 5 volt rail which is good. I seem to remember having to inert pins into the backboard sockets to measure the +/- 12 volts but that entails the removaval of the entire controller and it's card compliment - not a job for today.
Meanwhile I have spares of the two video cards on order, and a memory card that has iirc 32 kByte of ram, and slots for three daughter boards that have the controller firmware on them. This card is minus the daughter boards but the chances are that mine are OK.
. . . .I didn't need this . . . :med:
Post by: awemawson on July 30, 2021, 05:47:39 AM
My son in Houston, bless him, has bought that interface / memory card that I linked to and you encouraged me to get and will post it on to me I'm sure at a much lower price than the $192 the seller was quoting !
In addition to the two video cards, and the bare memory card (sans daughter cards) I have put in a half price offer for a CPU card which has been accepted :thumbup:
Incidentally it turns out that the memory card in this 820T is NOT populated with the extra 32K of RAM - presumably other models have it.
This >should< mean that I eventually will have spares of all the cards in the controller when international couriers do their bit - all of course are used items, sold as working, but I suspect that dealers probably have no way of testing them so we will see . . .
Meanwhile I have extracted the entire 820T controller from the rack for easier working on the bench. I seem to remember that when I first got the controller to come back from the dead when I got the machine, I was able to bring it up to 'Initial Clear' mode on the bench and only wired to mains - hopefully eventually I can repeat this :scratch:
Frustratingly I cannot find my 'Lab Book' covering that initial resurrection period (I try to keep notes on the more complex bits) - my current book only starts at 7th Sept 2018 yet the controller was up and talking to me by 21st June 2018. It's somewhere, it's A4 and blue - but WHERE :scratch:
Meanwhile some pictures I took really to make sure that I know where things go when / if I ever get it going again:
Post by: awemawson on July 30, 2021, 09:44:15 AM
(Screen is actually all white - the green bit is something to do with the camera and scanning)
According to the book of words the screen takes RGB TTL levels from the video-graphics card so I need to scope it and see whats what. No time at the moment as cottage guests due any moment.
However I HAVE managed to prove that the +5, and +/- 15 volt supplies are making their way along the back board - I actually found the original leads that I'd soldered wire wrap pins to back in June 2018 !
Post by: Pete. on July 30, 2021, 02:26:34 PM
Post by: awemawson on July 30, 2021, 02:46:20 PM
We lost power from 05:30 to 14:45 that day. But initially it was going on and off repeatedly (woken by iPhone that was on /off / on charge objecting !)
Many flashes of lightning, and we lost one battery backed timer program out of five installed around the farm - (fortunately only the pond pump!) and this lathe electronics. However the setting for the DNC controller that connects this lathe to my network (By RS232 cable) were also wiped out - I suspect that it was currents induced in this relatively long cable that caused the problem, but how do you prove it in the absence of a smoking gun?
The lathe WAS isolated at the time so it can only be induced currents.
I know it's proving a right royal pain to sort out !
Post by: awemawson on July 30, 2021, 03:29:04 PM
I came over to the workshop this evening to set the scope up to look at the backboard bus. I have no diagrams but it's amazing what you can deduce of card activity if you are persistent.
But I thought, just because I could, I'd return the cards to the card cage and see what happened. Darn me it comes up talking to me! Now it's reporting a "Battery Alarm Power Supply" which isn't surprising as the battery is disconnected !
Plugging back the (modified and remote) battery it now comes up "Ord 1 PP-Memory wrongly Formatted" which is probably not surprising - be good if I knew what 'PP-Memory' was but never mind - I now have a means of diagnosis as I can SEE things on the screen.
. . . life is full of mysteries . . . :scratch:
Tomorrow I need to perform a rigorous and methodical re-run and see what does what when other cards are plugged in !
. . . fingers crossed . . .
Post by: awemawson on July 30, 2021, 03:44:27 PM
(Thanks Google :wave:)
Post by: Sea.dog on July 30, 2021, 04:22:14 PM
Post by: awemawson on August 01, 2021, 06:17:25 AM
The other day I carefully returned all the cards to the card cage and temporarily returned the 820T controller to the lathe cabinet. But before I did this I sorted out a height discrepancy in the runners that it sits on. Left side was about 1.2 mm too low resulting in great difficulty aligning it's screws, and as the flange for the screws is fragile plastic it needed sorting. A simple packing piece was inserted under the runner.
So with it back in the lathe the controller was quite happy going through the entire software re-loading process without reporting any errors.
At this stage all seems normal, the machine can be referenced, jogged, tools turret operated, hydraulic chuck and hydraulic tail stock all worked as they should.
BUT issuing an M03 or M04 (CCW or CW) rotation command for the spindle with a suitable speed value resulted in no rotation, maybe a feint hum, and after a few seconds an error message reporting excess spindle speed (!)
The other oddity is that certain reporting and error messages displayed on the screen should comprise of a number followed by an explanatory text. The number is there but no text, so for example: "6000 Initialise Turret" displays as just "6000" . Now the translation is in a file called PCA.TXT which HAS been loaded - all very odd.
So trying to bottom out the lack of rotation I opened up the connections for the KTK Mentor DC Drive to get at the DC speed command input (+/- 10 Volts sign indicating direction) and was amused to see my clip links still in place from the last time - very convenient!
Measuring the speed command voltage it remained resolutely at 0v - mmm . . very odd. Now the controller is asserting the drive enable signal so all it needs to spin is a small DC voltage to say how much and which direction!
Well years back I made a little DC servo drive box - simple affair - 9v battery, suitable potentiometer, and a reversing switch. So it got a new battery and set to work.
Sure enough, I can drive the spindle quite happily from the little box until the control again reports spindle over speed and drops the drive enable signal.
This actually is quite a relief as this vintage of KTK Mentor are thin on the ground, and even if you can find them they command silly prices.
So what are we left with? Logically the lack of decoding of those numbers points to software in some form (firmware or what I loaded) and the lack of servo drive voltage could be either software or hardware.
Until a few more spares arrive I think I'm at an impasse :scratch:
Post by: nrml on August 01, 2021, 01:46:01 PM
Post by: awemawson on August 01, 2021, 02:08:10 PM
(I actually don't NEED a huge heavy CNC lathe at all, but I WILL repair this one I sincerely hope)
Post by: tom osselton on August 01, 2021, 04:23:52 PM
Post by: awemawson on August 02, 2021, 12:20:11 PM
A parcel from Germany arrived remarkably promptly (Thanks Fedex) containing the two video card spares and the card that hold the three daughter boards that have the main operating system in EPROMS. Now I really don't think these are anything to do with the issue that I am pursuing, and although I have unwrapped them, I have not yet tested them.
My Disco had to go for it's MOT today, so I got the wife to drop me off at the chap who always prepares it on it's annual outing (ex REME knows Landrovers!) and as a sweetener I took her to a rather nice pub (Two Sawyers, Pett Level) so she doesn't have to cook this evening. Lubricated with a drop of Harvey's Best Bitter I got to thinking when I returned - it's almost as though this machine either doesn't know that it HAS a spindle drive system, or that it is inhibited in some way :scratch:
The spindle drive system in block form is pretty simple (but they are VERY complex blocks!). DC motor with a Tacho and Encoder attached which is driven by the KTK DC drive. This takes it's command from a DC level set by the 'Measuring Card' that compares desired speed and direction given by the CPU with measured speed and direction from the tacho and encoder.
Does the encoder work? Well yes, once the drive has been told to turn (and failed) you can see the rotational position of the spindle via the controller. So there's a 'tick in the box'.
. . . about now a light light started to glimmer, and get brighter by the second. There is a page of 'spindle settings' tucked away in the controller specifying 'Acceleration Ramp Time, G92 spindle Speed limitation, M19 exact spindle Stop location, and Spindle Speed Limitation Everything was set to zeros.
If you limit the spindle speed to zero, it AIN'T going to spin :lol:
Now I thought that these settings were included in the re-load process, but it seems that they are not. Setting sensible values and now I have a lathe that turns it's spindle on demand - in fact just what a lathe SHOULD do :clap:
I'm still left with the oddity of missing text on the error messages but I bet that that tuns out to be some setting that's been zapped !
Post by: RussellT on August 02, 2021, 01:43:35 PM
It's very satisfying when you can work it out like that. Well done.
Russell
Post by: Sea.dog on August 02, 2021, 02:03:37 PM
Post by: Pete. on August 02, 2021, 02:55:54 PM
Post by: tom osselton on August 02, 2021, 03:02:42 PM
That’s something you wouldn’t expect you’d think it would have a minimum generic setting.
Post by: awemawson on August 02, 2021, 03:06:59 PM
Other examples: I have a complete set of electronics and servos for my H425 Spark Eroder in a crate in my container alongside another with virtually all the bits of a Fanuc Wirecut wire eroder.
I suppose it comes from a lifetime career supporting obscure equipment in critical applications.
Years ago we were taken over by an organisation more accustomed to supporting commodity PCs where there were usually many substitute spares available at short notice from dealers at low cost. Seeing some exceedingly rare CPU modules on the books at well over £50K a piece the new MD wanted them written off pronto to make the books look better. When I pointed out that they supported a fair proportion of the National Grid infrastructure including Nuclear Power Stations that we had very tight contractual commitments to, and that they could no longer be made his face was an absolute picture :clap:
Post by: vintageandclassicrepairs on August 02, 2021, 06:07:35 PM
Well done on getting the lathe electronics sorted, It is always a good idea to take some time away from the problem,
I have found solutions to problems appear in my mind at the oddest of times and places (if that makes sense?)
John
Post by: Sea.dog on August 02, 2021, 07:17:14 PM
Post by: modeng200023 on August 03, 2021, 01:40:29 AM
John
Post by: AdeV on August 03, 2021, 02:10:23 AM
Which tube would that be? :scratch:
John
The London Underground system, I'm guessing?
Post by: awemawson on August 03, 2021, 02:22:37 AM
Post by: russ57 on August 03, 2021, 06:27:30 AM
Graham, I rarely resent buying spares for these things when they are available and the price is sensible. It makes diagnosis so much easier in the future. A case in point is the little battery backed RAM card that seems to have succumbed to the lightning storm - I had it because it had flitted by on eBay about a year ago. Without that spare I'd still be scratching my head
Other examples: I have a complete set of electronics and servos for my H425 Spark Eroder in a crate in my container alongside another with virtually all the bits of a Fanuc Wirecut wire eroder.
I suppose it comes from a lifetime career supporting obscure equipment in critical applications.
Years ago we were taken over by an organisation more accustomed to supporting commodity PCs where there were usually many substitute spares available at short notice from dealers at low cost. Seeing some exceedingly rare CPU modules on the books at well over £50K a piece the new MD wanted them written off pronto to make the books look better. When I pointed out that they supported a fair proportion of the National Grid infrastructure including Nuclear Power Stations that we had very tight contractual commitments to, and that they could no longer be made his face was an absolute picture :clap:
. Seeing some exceedingly rare CPU modules on the books at well over £50K a piece the new MD wanted them written off pronto to make the books look better. When I pointed out that they supported a fair proportion of the National Grid infrastructure including Nuclear Power Stations that we had very tight contractual commitments to, and that they could no longer be made his face was an absolute picture :clap:
My brother has some stories about stores.
Item value 50k. Min stock level 2, , max stock level 2. Item required for urgent maintenance, but 'can't have it, stock would be below minimum...
-russ
Post by: Sea.dog on August 03, 2021, 06:41:12 AM
Post by: awemawson on August 03, 2021, 08:11:39 AM
Post by: awemawson on August 04, 2021, 11:20:17 AM
This is just to drive a solenoid valve to depressurise the coolant system when not being pumped, to allow the parts grabber (which is coolant powered) to open. I have hard copies of the minor change - it only involves two PLC segments - but not in a format that allows me to upload it as part of the normal reload procedure.
So today I took a trip down memory lane, re-learning how to connect my Win XP powered Toughbook running 'STEP5' to the PLC. Amusingly, the correct version of the PLC code is still showing within the program, but I've not yet rediscovered how to upload the local copy to the PLC. If all else fails I can edit the code within the PLC to match my printout, but that's cheating!
Now I have to say that having uploaded masses of screen shots when I was doing it back three years ago, it has been a very handy resource to set me on the right path, as believe me STEP5 is not at all intuitive !
:mmr:
Post by: awemawson on August 05, 2021, 05:51:16 AM
Back ups downloaded and put on two separate PC's in separate buildings along with a copy blown to CD and placed in the pocket inside the machine door - don't want to have to jump through these hoops again.
Still got the mystery of the error code numbers not being translated into text from the PCA file but that's not a show stopper. Conceivably it could be that little battery backed RAM card that I had to replace - maybe an oddity with the replacement. A further spare has arrived with my son in Houston yesterday and will be coming by shanks pony in due course.
Post by: hermetic on August 05, 2021, 02:53:33 PM
Phil
Post by: awemawson on August 05, 2021, 04:54:47 PM
Post by: hermetic on August 06, 2021, 04:36:15 AM
"This phrase seems to be of Scottish origin. It is first recorded in The Tea-Table Miscellany: Or, a Complete Collection of Scots Sangs, published in 1729 "
I had assumed its "wezzy" origin because I have seldom heard it used in East Yorkshire!
Phil, Arm deep in Fordson hydraulics!
Post by: vintageandclassicrepairs on August 06, 2021, 05:51:45 PM
Funnily enough "Shanks Mare" was commonly in use here in Cork (Ireland) when I was a youngster back
in the sixties
John
Post by: awemawson on August 07, 2021, 02:17:35 AM
Post by: mattinker on August 07, 2021, 08:03:41 AM
Post by: PekkaNF on August 25, 2021, 05:05:58 AM
....
So today I took a trip down memory lane, re-learning how to connect my Win XP powered Toughbook running 'STEP5' to the PLC. Amusingly, the correct version of the PLC code is still showing within the program, but I've not yet rediscovered how to upload the local copy to the PLC. If all else fails I can edit the code within the PLC to match my printout, but that's cheating!
Now I have to say that having uploaded masses of screen shots when I was doing it back three years ago, it has been a very handy resource to set me on the right path, as believe me STEP5 is not at all intuitive !
:mmr:
First PLC programming language I learned and it was still not intuitive....even though I has suit case full of reference manuals, I had attended few lessons, I had been reading the manuals (in German, that time all the newest were in German and programs were in german too) and I had tagged along senior programmers. Ladders, timers etc. I go pretty familiar with, but assembly math and smart bit operations on tight control loop always raised my blood pressure. When making changes on running PLC while the machine was running production my blood pressure was off the chart and I was swatting bullets right when I pressed the <> key on old programmer to send out the to PLC.....hold my breath for few seconds and usually it went fine, but sometimes PLC stopped and everything went into safe mode with all noise and cacophony and signal lights went off....I could feel every eye trying to bore holes trough me....check error code, deside how to proceed and put the system up and running before whole plat goes down....don't miss it any more. I don't wake up at night on nightmare and start to think that did I checked the code right and make sure that everything is documented to last bit....all few thousands of I/O points and relevant programs. No one can do it alone, bit if you are the one that downloads the programs and flips the switch to "RUN"?
Good job keepping the hard copy, local copy and PLC up to date. There were some problems with this. You could upload the program and sometimes you didn't have the original program....working with downloaded program (without comments, titles and I/O functional names was fun. Even more so, if you had most of the program ans then decided to download something from PLC, it would wipe out the commets from similar named nets. We used download only for backups, programs were always uploaded. Live (hot fixes) were rare and generally frowned upon. Good times, but such times that will not be missed.
Post by: awemawson on August 25, 2021, 07:09:18 AM
Now it was this little RAM card that had failed when I had the lightning, and although I had a spare with which the machine worked, it didn't translate error numbers into error text after it was fitted. As the file of error texts is stored in the RAM I wanted to try a second spare, hence getting this one.
Well, ominously, the lithium battery on this recent card was absolutely flat - not even millivolts - I've seen several of these cards but the batteries have always had something in them - reputedly they are good for ten years but there is no date on the battery.
As the battery had to be unsoldered anyway I thought that I might as well fit my 'remote battery' lead to it as that's the eventual configuration the I want to end up with.
OK battery transplant done, machine reloaded, but various error messages. Three more total wipes and reloads (which is quite a complicated process!) performed but with the same results.
Accepts facts Andrew, the card is dead :(
So first replacement RAM card re-installed - a further total wipe and re-load performed and we are back running but of course still without error texts.
So I now have two (or is it three :scratch:) faulty RAM cards so I want to reverse engineer them for testing and repair.
They look fairly conventional with four 32k x 8 bit static Ram chips and minimal logic gluing them together and a bit for isolation of the main 5 volt rail when on battery back up.
Mind you it's all a bit small for my old eyes and will involve magnifiers !
Post by: Sea.dog on August 25, 2021, 10:17:31 AM
There are some cheap, UK stocked ones on eBay - https://www.ebay.co.uk/itm/224365359347
Obviously the first thing that you'll check are the "easy" surface mount components. I would not expect there to be any problem with the resistor packs, but you never know.
Post by: awemawson on August 25, 2021, 10:48:33 AM
My copy is dated 2002 so I would have expected it to be in the 'known chips' provided by Altium, but it isn't
. . . my head hurts . . :coffee:
Post by: AdeV on August 25, 2021, 01:31:31 PM
Maybe it'd be worth contacting NEC directly for a pinout, and you'll definitely have to draw your own symbol!
Is it definitely the "V" variant (16 pin single-in-line)? The DIP version ("C" variant) returns waaay more results.
Post by: AdeV on August 25, 2021, 01:36:30 PM
As I'm registered, I downloaded the file & it has an Altium footprint in it... I can forward it to you if you like.
Post by: awemawson on August 25, 2021, 02:29:21 PM
Thanks but I have the pin out and a copy of the data sheet. I started defining the chip as a component in Protel just before supper, but then realised that I'd made the outline far too big. I'll re-do it in the morning. It's just to be able to draw a readable circuit diagram that I can easily modify, I don't intend to incorporate the twinkly bits for Spice modelling etc as I don't need them.
Last time I did this I was resurrecting the Numericon 850 control on a Chipturn CNC lathe back in 2012 so my memory of the 'how to's ' is rather hazy - after all it was four CNC lathe rebuilds ago !
Post by: Sea.dog on August 25, 2021, 03:20:28 PM
Post by: awemawson on August 25, 2021, 03:40:07 PM
I'm looking forwards to this thread hitting fifty pages :D
Just a short one then you think Graham :clap:
Post by: awemawson on August 26, 2021, 02:29:59 PM
I've created a 'pin out' model for the actual RAM chips and the resistor arrays as they didn't exist in Protel, and I've started drawing an embryo circuit diagram with all the components, so that as I identify inter-connections I can edit the drawing accordingly. There is a 'dual analog precision comparator chip which did exist in Protel, and several SMD three legged (transistor / dual diode / MOSFET) SO-23 devices that are proving elusive to positively i/d. One is definitely a PNP transistor but hopefully the other three will become obvious as I map the circuit.
Rather fuzzy photos of them from several angles haven't really helped much - they are only 2.9 mm x 1.45 mm ! They have a very faint possibly 'A J' printed on them
I am expecting that the 'dual precision comparator' chip will be being used to monitor the back up battery level, as an alarm should be generated if it falls too low.
The unidentified three legged devices I'm pretty certain are in the change over circuit from normal to battery power - I'm attaching a circuit of a typical change over circuit that amusingly is servicing a similar static ram chip and this circuit will probably closely follow it.
Tomorrow if I get a chance I will model the 48 pin card connector and start doing the virtual wiring up - hopefully things then will become a bit clearer.
Post by: awemawson on August 27, 2021, 10:24:31 AM
To that end I removed the mating socket from the original Interface Card that had been dissolved when the first RAM card spewed it's lithium juices before I got the machine. I reasoned that although interesting, I was never actually going to re-use it, so the manner of removing the 48 pin socket didn't have to be delicate.
. . . blowlamp to the rescue . . and off it came in excellent condition, which is more than can be said for the PCB it came off !
I can now start mapping the outside world contacts to the various address and data lines onboard the card.
Duty calls so more later.
Post by: awemawson on August 28, 2021, 11:44:04 AM
Although I've traced the logic for the chip select signals back to the card connector I've not yet sussed the switching between the two pairs of ram chips, this switching must form the 16th address bit to map all the memory.
Yet to do is trace out the Vcc (+5v) logic supply switching and the battery (3.7 volt) stand by switching that involves the various SMD chips and the analog comparator chip that I thinks is for low battery alarm.
It looks like some of the SMD chips may be power supervisory circuits:
"The PT7M7xxx family microprocessor (μP) supervisory
circuits are targeted to improve reliability and accuracy
of power-supply circuitry in μP systems. These devices
reduce the complexity and number of components
required to monitor power-supply and battery functions"
But that is more joy for tomorrow, I need to uncross my eyes !
Post by: awemawson on August 29, 2021, 11:30:56 AM
I initially concentrated on the 'low battery alarm' circuitry which uses a dual precision comparator chip. Got it's wiring worked out but I couldn't for the life of me find where the output of the second part went. I couldn't trace ANY pcb tracks but it's not easy with SMDs ! Bright torches help shining from the other side, but not in this case. In the end I decided to butcher the original battery RAM card that was dissolved by the lithium juice prior to my ownership, and take the 8 pin SMD off the board. Hot air gun suitably applied only to reveal that despite the fact that it's inputs are connected, IT'S NOT USED :clap:
OK go back to chasing real bits not virtual ones. Next on my list to nail was the three pin SMD labelled '45'. The look up list for SMD's said it could be a pair of diodes, a single diode, a transistor, or a voltage regulator so not much help. In the event looking at the original card (where this chip had completely disappeared!) in fact only two pins had tracks attached so it could really only be a diode (probably schottky from my meter readings)
Time to try and identify the SMD device labelled 'AJ' - again the list said that it could be almost anything, so I decided to pull one off the scrapped board and try and test it. Fiddly things these SMD chips - breath and they skid all over the place. In the end I super-glued it to a bit of wood, pressed pins in adjacent to the connections, and biased them together with a Hellerman rubber sleeve. Didn't do me any good - my component tester had no idea what it was. So I've drawn up just a block with three connections for the circuit drawing hoping that it's identity might be revealed by context.
I still have quite a few 10K resistors to positively tie to places in the diagram - several are definitely pull ups for gate inputs from the outside world, but I'll save to joy of finding them for tomorrow!
Post by: jiihoo on August 29, 2021, 01:37:04 PM
Tying all inputs of CMOS chips to a high or low level should be standard practice. Most CMOS chips (logic gates and comparators) will start oscillating if they have floating inputs, which can cause excessive current consumption and may interfere with adjacent circuitry. I assume Andrew knows this; this explanation is for others reading this thread :D
Post by: awemawson on August 30, 2021, 06:28:10 AM
Of the 48 pins on the edge connector only two are not used (C15 & C16)
I still don't know what the SMD chips 'AJ' actually do, but from the circuit you can see that they are turning on the PNP transistor 'SMD-DB' when 5 volts is coming in from the edge connector, and turning it off when it's not present allowing power to pass to the RAM chips normally from the incoming supply, and be powered via the diode '45-SMD' from the lithium battery when system power of 5 volts goes away.
By my calculations the 'Low Battery Alarm' (Pin A16) should be asserted when the volts of the 3.7 volt nominal battery fall to 2.8 volts.
Now I have the circuit I need to work out how to actually test it and hopefully fix what is wrong. The battery side should be pretty simple. Power up the card with 5 volts, replace the battery with a variable lab supply and see what happens when the voltage is lowered from 3.7.
However testing the rest isn't quite as simple. Simplistically all 16 address lines and 16 bi-directional data lines should be able to be toggled by applying a TTL signal so any 'stuck bits' could be found, but Id like to build a proper tester that writes to the ram and checks what is written. My first thought was something like an Arduino, counting up the address line in binary, and performing a write and a read but the number of input output pins gets large.
16 address, 16 data, plus Chip Select, Write Enable and Output Enable is 35 I/O lines - will an Arduino do this - I have no idea never having used one! I can cut the number down by 15 to 20 by building a 16 bit counter circuit for the address lines and just incrementing it but that limits me to only testing addresses sequentially which is not ideal.
. . .so comments please from all those Arduino experts out there !
Post by: Muzzerboy on August 30, 2021, 07:29:54 AM
The LH device looks like pin 1 - base, pin 2 - emitter, pin 3 collector, which is a fairly normal configuration for a bipolar transistor. You can use the base-emitter of a bipolar transistor in reverse as a zener (typ around 6.8V breakdown?) or emitter-collector for that matter. I've seen a few circuits over the years where that's been done.
Trouble is, the supply voltage is only 5V, so you'd never get the base junction to avalanche. It seems to almost make sense - but not quite!
Post by: jiihoo on August 30, 2021, 08:27:00 AM
https://www.arduino.cc/en/pmwiki.php?n=Main/arduinoBoardMega2560 (https://www.arduino.cc/en/pmwiki.php?n=Main/arduinoBoardMega2560) has the specs.
I only dabble in Arduino, meaning I have a few of the boards and have compiled some simple sketches a few years ago. More knowledgeable members might be able to recommend a more optimal solution like a smaller Arduino with a suitable shield card. In my opinion the Mega ain't too badly priced and it would be a single board solution, so with my limited knowledge that's what I'd pick.
Post by: awemawson on August 30, 2021, 09:13:57 AM
Now the debate is on how much to do on board the Arduino and how much to bring back into the PC, but first I have a much simpler task - physically connecting to the 48 way edge connector in a way I can repeatably connect and disconnect things.
I rescued a 90 degree mounting PCB version of the correct socket, and I'd thought to just solder it into a bit of Veroboard for onward wiring, but it's three rows of 16 pins on a 0.1" matrix which rather scuppers that idea. I need a "DIN 41612 48 way breakout board" - I can't see that existing, or if it does King's Ransoms will be involved.
The pins are so flimsy that direct wiring even with sleeving, won't last ten minutes! Maybe the type of perforated board with separate pads might work, but I don't have any in stock ATM !
Post by: awemawson on August 30, 2021, 01:10:01 PM
The three rows of pins are accommodated but only the outer (A&C) rows are extended, the remaining B row just having isolated pads but it should work OK I think.
Another bonus - I've found some Arduino 2560 Mega code on Github that has been written to test 62256 ram chips which should prove a time saver - OK I need to tweak it as it is only doing 25% in terms of data width and address length, but the donkey work has been done :thumbup:
Post by: mc on August 30, 2021, 01:56:10 PM
I was going to suggest a Raspberry Pi, depending on what programming language you prefer, but having just checked, they only have a maximum of 17 GPIO pins.
Post by: awemawson on August 30, 2021, 02:09:56 PM
Speed isn't really an issue, it can just churn away counting through all 64K addresses with 64 data variants, though probably I won't, I'll do all ones, all zeros and the old U*U* sequence which gives alternate ones and zeros.
In practice I'm not looking for marginal issues with this RAM, it'll either work or not, but the tester will let me exercise the address lines and data lines which I can then check with a 'scope while it's running !
I suspect that the EPROM cards in this controller use exactly the same interface (except for writing) so hopefully I'll be able to peek inside them as well.
Post by: jiihoo on August 31, 2021, 05:15:54 AM
Two different kinds of memory tests are needed: Ones that exercise the memory byte-by-byte or word-by-word and ones that exercise the address lines.
1) All ones, all zeros and 0x01010101 written one memory address at a time are of the first category (exercise each memory location). So is the classic "walking bit" where you walk first a 1-bit through a memory location (with all other bits being zero) and then continue this from the next memory location until end of memory. Once the whole memory is tested this way you'd follow this up with a walking 0-bit test.
This category of tests proves that each of the data lines works and that each memory location works assuming the address lines worked correctly. And that is an assumption that needs to be verified next.
2) This category of tests verifies that all address lines work correctly and that each memory location really is a separate memory location. Here you need to first fill the whole memory with some non-repeating pattern (or a pattern that does not have a cycle length divisible by 8) and then read it back verifying that each memory address returns what was written there. You could use the fibonacci sequence (1, 1, 2, 3, 5, 8, ...) for this (use unsigned integers for the math; yes it will overflow but that does not matter as there should always be enough variance in the least significant bits that are left after an overflow...) Or you could just write "memory address + 11" to each memory location (the +11 is arbitrary but important as you don't want to use the same data as the memory address...). Anyway, write all memory addresses with your chosen sequence first and then read back all memory addresses and verify that the expected data is there.
Why is the category 2 test needed? Well, assume you have a 16-bit system (64k addresses) that has a solder bridge between the two most significant address line bits. Or a broken memory chip that internally shadows the upper half of its memory on top of the lower half. The first category of tests is not going to catch that. What will be seen is that the lower 32k of memory works correctly and the upper 32k of memory works correctly when tested byte-by-byte or in blocks less than 32k, but once the whole memory is tested at once it will be noticed that the upper 32k is the same as the lower 32k...
Actually if testing byte-by-byte even totally unconnected data lines might pass the test if there was a sufficient amount of stray capacitance on the data lines...
My real-world experience with the memory test that didn't find problems was only doing the category 1 test, I think it was doing the walking bit test. This kind of test is ok if you are looking for random errors in memory that is otherwise working ok, but not ok for finding soldering mistakes in production or badly misbehaving memory chips.
Post by: awemawson on August 31, 2021, 05:57:10 AM
(This is often followed by 'inverse own address')
As you say overlapping addressing will never show up on a 'write a byte, test a byte' test as you don't really know where it is putting the data.
Post by: awemawson on August 31, 2021, 09:59:26 AM
Post by: Muzzerboy on August 31, 2021, 01:14:27 PM
Post by: awemawson on August 31, 2021, 02:04:00 PM
The intended one is on resistor pack G pin 2.
Are you maybe confusing edge connector pin A12 with Signal A12 - I know it's a nightmare of alphanumerics !
Later Edit:
Ah found what you mean
Post by: awemawson on August 31, 2021, 02:22:28 PM
Post by: awemawson on September 03, 2021, 06:03:03 AM
Arduino Mega 2560 R3 has arrived - it did a few days ago but farming things took priority. I did just plug it in and download the IDE (Integrate Development Environment) and write a little diddy LED flasher but it failed to upload and no time to sort it out.
But today I had time to have a 'look see' : Simple really, tell the compiler that you have a Arduino 2560 R3 and not the Uno that it was set up for and it WILL upload :ddb:
So a bit of playing about changing flash rates etc - nothing at all complicated, then I went off to GitHub and cloned the already written code for the 62256 SRAM chip to see how the author has approached the problem. The code compiles and runs but of course isn't connected to anything yet, but at least it's basically working, and will give me good ideas to structure my own version.
Still awaiting the breadboard and anyway being a Friday another two cottage change overs to perform and tomorrow a field to flail so hopefully Sunday or Monday I'll have a crack at it.
PDF version of the cloned .ino file attached - now I need to discover how to open .md read me files and I'll be well away :thumbup:
Post by: russ57 on September 03, 2021, 07:31:18 AM
Probably rename would be easiest..
-update = md is markdown so it could have formatting tags
-russ
Post by: awemawson on September 03, 2021, 08:36:53 AM
I presume that there's a way of opening .md files within the IDE but I've not found it yet.
As he doesn't vary his data it's amusing to watch it 'pass' my open wires as good, but never the less it's a very useful introduction for me.
I'm quite looking forward to get it driving the RAM card - a load of jumper leads arrived this morning, and supposedly the break out bread board is 'out for delivery' but no sign yet !
Post by: AdeV on September 03, 2021, 06:10:27 PM
Yes I whipped the .md off the file name and opened it with Notepad. As you say it's just text but un-formatted so I saved it with word wrap on to make it marginally more readable.
I presume that there's a way of opening .md files within the IDE but I've not found it yet.
The Arduino IDE is pretty rubbish by modern standards, although having all the tools to make it talk to the Arduino makes it handy. Your best bet for reading .md files is actually to read them on-line (the default README.md is shown automatically by github, underneath the list of files. Any .md file you click on in the github list will also render nicely on the browser.
Failing that, download & install Visual Studio Code (free from MS). It will run on anything (Windows/Linux PC or Mac), and will also render .md file (right-click the file, open preview).
As he doesn't vary his data it's amusing to watch it 'pass' my open wires as good, but never the less it's a very useful introduction for me.
I'm quite looking forward to get it driving the RAM card - a load of jumper leads arrived this morning, and supposedly the break out bread board is 'out for delivery' but no sign yet !
Welcome to the wonderful world of Arduino! :borg: The "usual" way of increasing the number of useful data pins is to use one (or more) 74595 chips (serial-to-parallel) or 74165 (parallel-to-serial) shift registers, which at the expense of a bit of speed, gives you a effectively as many digital I/Os as you could ever need. :headbang:
Post by: awemawson on September 04, 2021, 02:46:48 AM
All driven off a single bit on a PC parallel printer port. (A second bit acted as clock) Amazingly it actually worked quite well.
(The Hydropoint blew air though several stripes of holes at once in the paper tape and the air drove tiny actuators moving parallel plates with holes in that the hydraulics servo system used as it’s set point. That was quite a learning exercise!)
Post by: mc on September 04, 2021, 03:42:34 AM
An alternative for reading .md files, is Notepad++
It's quite a handy text editor, and I have it installed on most of my computers.
Post by: awemawson on September 04, 2021, 05:58:29 AM
Post by: awemawson on September 04, 2021, 10:59:06 AM
This has allowed me to prove that the low battery alarm circuit on both cards is working correctly (+5 volt for Battery OK, close to zero for low battery).
Card #1 has a 'transition voltage' for the battery alarm exactly at the calculated 2.8 volts, but card #2 has a trigger point of 3 volts. I don't think that this has any significance but we may see later that that's a false assumption!
The bread board having arrived has let me think a bit more about the physical side of further testing, or rather oscilloscope probing of the board under test. As most components are SMD's, unlike through hole devices you need to be able to probe both sides of the PCB. This dictates that either I stand the board vertically (which makes getting at it a pain) or have the board connector hanging off one end of the breadboard.
I've chosen the later method but this has persuaded me to incorporate header pins to connect to the Arduino rather than as I had previously intended - using directly soldered flying leads. My drawer of rows of header pins is a bit on the low side so an order has been placed with RS.
Post by: Muzzerboy on September 05, 2021, 08:07:17 AM
I started out at Farnell Instruments (SMPS group) latterly Farnell Advance Power back in the early 80s, when Weir (and Coutant) were competitors. All gone now apart from Coutant who are owned by TDK (but still apparently living in the 60s).
Post by: awemawson on September 05, 2021, 10:44:48 AM
In proving the working of the circuit using dead board #1 I was going round in circles as it turns out that the line on edge connector pin A12 wasn't being pulled 'high' by it's 10K resistor. Now that particular lines goes to several pins on both 74HC00D chips , and one of them is driving to 0v when powered up. Impossible to tell which without removing a chip. To this end I've ordered some (minimum order 50 off as they are SOIC-14 smds !)
Board #2 has a faulty "SMD DB" transistor which I believe translates to be a BCW67C - again in an SMD package - so I've ordered some of those (100 off for £1.94 !!)
So this is going to be a learning exercise in SMD reworking for which I've bought a hot air rework station etc - about time I got equipped !
Post by: modeng200023 on September 05, 2021, 11:03:58 AM
John
Post by: Muzzerboy on September 05, 2021, 01:49:02 PM
Post by: awemawson on September 05, 2021, 02:18:55 PM
Andrew, you just amaze me :clap:
John
Thanks John :palm:
Some more progress. I've linked out the faulty transistor from Collector to Emitter to allow me to carry on testing. This transistor is involved in the switching to / from battery back up so in this mode I can do without it!
This has let me prove that A12 inhibits all Chip selects when low, and the other four control lines (B13, B14, C13, C14 ) provide Chip Select for each individual Ram chip.
All a bit odd, but workable.
The picture of the link across the SMD transistor emphasise how small SMDs are - that huge hoop of billet is actually the lead from a tiny 1/8 watt resistor :clap:
Post by: PekkaNF on September 07, 2021, 05:08:52 AM
....
The bread board having arrived has let me think a bit more about the physical side of further testing, or rather oscilloscope probing of the board under test. As most components are SMD's, unlike through hole devices you need to be able to probe both sides of the PCB. This dictates that either I stand the board vertically (which makes getting at it a pain) or have the board connector hanging off one end of the breadboard.
I've chosen the later method but this has persuaded me to incorporate header pins to connect to the Arduino rather than as I had previously intended - using directly soldered flying leads. My drawer of rows of header pins is a bit on the low side so an order has been placed with RS.
I have bought this kit:
https://sensepeek.com/pcbite-kit-with-2x-sp200-200-mhz-handsfree-oscilloscope-probes
pros:
1: It has pretty much standard 10x scope probes and they work per spesification, the business end is small and has a standard needle pogo pin.
2: probes are held down with a weight and the swan neck tube holds them in place, it works
3: The magnetic standoffs works too.
cons:
Ground hook is not that great, but it has standard square pin connector and easily replaced.
I though of making something like that myself and played around of different parts etc. and never got really good results. I tried those cheap colorful flexible coolant hose thingys, but they really are not very precise or dependable in real use.
This commercial product does what I needed better that what I could have cooked. However it is just one part and I still solder wires and connectors on boards, just getting better at it.
There is a 1:1 flying lead probe too for non coaxial cables, but those I haven't tried.
Pekka
Post by: awemawson on September 07, 2021, 06:22:24 AM
I fear I'm stuck tagging on wires with solder at times !
Post by: PekkaNF on September 07, 2021, 08:34:45 AM
https://www.bot-thoughts.com/2013/01/easy-pogo-pin-test-jigs.html
https://blog.adafruit.com/2013/07/08/using-pogo-pins-to-shrink-6-pin-isp-connectors/
There are some easy solutions for batch of boards, but to test economically single board on hobby setting needs soldering - eventually.
Post by: awemawson on September 08, 2021, 06:03:49 AM
A bit busy today but I had to try it out. I removed a resistor pack from the original RAM card that got dissolved, and it seems that the pack is in good enough condition to re-fit if needed, so a good result for a first effort.
I need to research what temperatures to use - the solder melts below 200 deg C but most on line sources say use 250 which is what I did. But what temperature can IC's stand and still survive?
Post by: awemawson on September 08, 2021, 10:36:44 AM
So - first chip out and I powered up and A12 is still 'misbehaving' - so then I took the second chip out as A12 connects to two gate inputs on both chips. Argh - A12 STILL misbehaving :bang:
OK what's going on here :scratch: Well it turns out that the termination of these five control lines is not a simple 10k pull up to 5 volts, but also a 10 k pull down to 0 volts.
All five control lines pull up to 5 logic high and down to logic low with a 1K5 resistor so it's all been a none problem - how very familiar !
OK something else learnt, AND practice using the SMD hot air gizmo. I decided to re-install the two chips and darn me they have survived the exercise and still work!
But I MUST sort out physical connections to this board - pushing female jumper leads onto the edge connector is very unsatisfactory - I must knuckle down and solder up the bread board that I now have.
Still - happy that I can not only remove SMD chips but also put them back and they still work :clap:
Post by: awemawson on September 08, 2021, 12:23:09 PM
Well I've been waiting for inspiration to get over a little 'problem-ette' - the bread board designer certainly laid it out to take a DIN41612 three row 48 pin socket, but only the outer 'A & C' rows of pins are brought out to the body of the board - row 'B', the centre one, is all on it's ownsome lonesome and will need jumpers, which cannot be on the component side if the socket is to sit correctly.
OK it's only 16 links - 32 soldered joints - but I've been trying to work out ways round it ! Years back I'd do links like this in 'self fluxing' enamelled copper 'magnet wire' where a good hot soldering iron would volatilise the insulation, but I'm not sure if I have any left - time to go hunting in the wire stash :lol:
The plan is to have the Arduino fixed to the breadboard as you may well have gathered from the picture.
. . . I'm off wire hunting . . .
Post by: awemawson on September 08, 2021, 12:41:50 PM
Buried in a dusty box I found two rolls of self fluxing wire - one rather too thin and the other rather too thick - oh well 'it'll do'
Iron needed cranking up to 475 degrees C to effectively remove the enamel, but it DOES work !
More experimentation later I think
Post by: Muzzerboy on September 08, 2021, 01:26:28 PM
Post by: awemawson on September 11, 2021, 08:29:01 AM
Then I thought, if I can find a crimp version of the connector, I can put it on pigtails off the board and solve the issue. Sure enough, Harting part number 09230483217 is the right part - but it's on a ten week lead time from all the normal UK suppliers so that rules that out!
OK the socket that I have has solder tails intended for a PCB, BUT 16 way female socket headers fit them rather nicely - three of those and I have a hopefully working solution. Solder the three headers individually thus making the 'middle row' a none issue, push them on the back of the socket and hang the socket off the board on a short umbilical cable This also makes inverting the board for test far easier.
But as the female jumper leads that I've been using with the Arduino were themselves rather unreliable - falling off at a mere touch, a better breadboard solution was also called for. I've found one with screw terminals AND header sockets so this may be the best of both worlds.
. . . . we'll see when it arrives !
Post by: awemawson on September 13, 2021, 09:41:52 AM
I must say that I'm impressed by the build quality and it looks like it will meet my needs. I'm now waiting for a delivery from RS of '0.7 mm Boot Lace Ferrules' that will plug into the existing female push fit sockets AND go in the screw terminals (keeping my options open). I do have 1 mm boot lace ferrules but although they fit the screw terminals they are no good for the push fit ones./
. . . . getting there slowly - one tiny step at a time :thumbup:
Post by: awemawson on September 20, 2021, 06:58:03 AM
So I've reverted to 'Dupont' pins - which I don't particularly like as they are a bit fragile, but needs must, and of course this incurred a further few days of delivery delay.
OK we are where we are ! So today the coloured heat shrink arrived allowing me to code up the 48 wires. There are three banks of 16 wires, cabled in correctly colour coded wire, but being 1 to 16 each bank has two 1's 2's .... 6's. So each bank needs a sleeve to indicate which it is (A=Yellow, B=Red, C=Blue) and in each case wires 11 to 16 have a white sleeve to differentiate them from 1-6. This may seem pedantic, but believe me without this detail things rapidly get very confusing when fault finding !
So this morning I have done the wires and crimps of 'Bank A' and I'll give my eyes a rest until a bit later to stop me going cross eyed !
Meanwhile the programming of the test program has been progressing but isn't yet finished.
Post by: djc on September 20, 2021, 08:03:24 AM
Everyone wants to start counting at 'one', seemingly forgetting that 'zero' can be used.
When you see videos of people dismantling things (e.g. a chair), they label the legs 1, 2, 3, 4 when 1, 2, 3 and no label would do. How much masking tape is this costing the planet?
I wonder if there is any connection with a person's favourite computer language - whether arrays are zero-indexed or not?
Post by: awemawson on September 20, 2021, 08:10:03 AM
However, personally I think things should be labelled as what they are! If labelling a class of four items as 1-3 and no label, you are stuck when label 2 falls off, and in the real world this happens all to often.
Post by: awemawson on September 20, 2021, 11:01:50 AM
Post by: WeldingRod on September 20, 2021, 03:51:24 PM
Otherwise, if your tape fails you have two identically "not labelled" parts...
Sent from my SM-G892A using Tapatalk
Post by: vintageandclassicrepairs on September 20, 2021, 05:19:07 PM
I have to admire your enthusiasm and energy pursuing this fault finding "adventure"
In a previous life I worked as a spark and instrument tech at a combined cycle gas fired powered station
Seeing the multitude of connections on your "test rig" reminds me of my work back then
All long gone now (including me)!!
John
Post by: awemawson on September 20, 2021, 05:31:28 PM
I don’t HAVE to do this but it keeps my brain working!
Post by: awemawson on July 08, 2023, 07:13:53 AM
You may recall that the original demise of this machine was due to the lithium 'Tadiran' on PCB RAM back up battery having let out its juices and dissolving much of the Siemens CNC controller, so when I got it all working I mounted a remote battery in a leak proof case away from the electronics. This worked well but a few months (years maybe?) later we had an electrical storm IIRC that took out the little ram card that the battery had been mounted on.
This card backs up many setting and parameters of the machine and is vital to it's operation. However they are rare as hens teeth and come in several incompatible versions. I eventually found one that 'almost worked' - every thing was fine EXCEPT for a look up table that is stored on this card that translates error numbers to plain (ish!) English. Load sequence worked but errors still show as numbers not text. I spent weeks reverse engineering the RAM card - and manually proved that all the addressing and other peripheral logic on the card was fine - but what about the RAM chips themselves - was one faulty.
I then spent several fruitless weeks trying to make a RAM tester using an Arduino but never got a good setup, and the bits have been om my desk in the workshop for well over a year - glowering and nagging me.
Well I decided - hang it, source the RAM chips and change them ! They are four 28 pin surface mount NEC D43256GU-12L -I found a source of the chips - bought myself a cheap SMD rework station and . . . .bottled it ! My eyesight was never good and with anno dominae isn't getting better.
However today I braced myself and made a determined effort using a bench magnifying lens.
To remove the original chips I used loads of flux and Quick-Chip ultra low melting point solder. Strange stuff - extremely brittle and stays molten for a long time allowing the old bits to be removed. However due to this brittleness it is important to remove ALL of it before soldering in the replacements. I used normal Solderwick again with loads of flux, then cleaned up the mess with IPA.
Much watching of YouTube videos told me the virtues of 'drag soldering' - never heard of it before - but essentially you anchor the chip at opposite corners by conventional soldering with a very fine tip iron - then load the tip with excess of solder and drag it across the remaining pis, where the excess of flux and surface tension pulls the solder into the places that it's needed. Amazingly the process seems to work - I had a couple of solder bridges but they were cleared fairly easily.
So after a lot of flux clean up I re-assembled the RAM card with it's retaining handle and umbilical cord, and now I need to find the time / courage to try it in the machine. Lengthy re-load procedure so not today.
Still I overcame the SMD soldering issue and fears :thumbup:
Post by: awemawson on July 09, 2023, 07:58:38 AM
Initially I steamed up my copy of DNC4U intending to talk to the lathe and check its comms as I've not used it for some months. The program said "What Interface?" - my Startech USB to 4 port serial box that's been working for years was only showing two of it's four serial ports and thus the Beaver wasn't connected.
Much faffing about with USB cables USB hubs UPS power sources - PC re-booting and yes at last it found the remaining ports that even still had the correct settings.
OK find a directory with the correct back up to re-load, unplug the RAM card with integral battery, plug in the one where I've changed the RAM chips and not surprisingly it comes up wanting reloading. First step is to power the control down bring it back up pressing the "Eye Key" which is used to get into the set up side of the control. Well it won't come up at all - blank screen - zilch.
Revert to RAM card with integral battery - up she comes and all is well
Try two more times with my 're-chipped' ram - same symptoms - argh we are no better off than we were but at least no worse.
Could be faulty RAMS or more likely forgeries - oh well, slink off and lick your wounds :bang:
Post by: hermetic on July 10, 2023, 04:41:15 AM
Phil
Post by: awemawson on July 11, 2023, 07:53:15 AM
I don't want to unsolder its battery and connect it to the remote battery until I have a working spare, as if I can't reload it the lathe will be unable to function.
I've fired off an email to a repair company to see what astronomical fee they'd ask to either supply or fix - we'll see what happens !