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The Craftmans Shop => New from Old => Topic started by: awemawson on May 19, 2018, 07:14:19 AM

Title: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 19, 2018, 07:14:19 AM
Well I've been and gone and done it again  :bugeye:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 19, 2018, 07:22:47 AM
The fellow who is selling has lost all the documentation and also the tool setting probe which is very sad, the Siemens stuff is all available on the web for download but Beaver went out of business in the early 1990's so the machine specific stuff is thin on the ground.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Joules on May 19, 2018, 07:26:44 AM
You have a problem Andrew, what with this knowledge of skipping porn stars and an addiction to Beaver, you really should seek help.

       :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on May 19, 2018, 07:52:36 AM
I await the next awemawson epic. Showing on a forum near you, soon!  :clap:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 23, 2018, 12:55:40 AM
Well a tiny bit of progress, I've located a Renishaw tool setting probe. You'll recall the seller of the lathe lost his  :bang:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 23, 2018, 08:54:35 AM
Well today is officially a GOOD DAY  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 23, 2018, 10:20:26 AM
Do you believe in co-incidences ?

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brass_Machine on May 23, 2018, 01:16:32 PM
So Andrew....

Nice find! But, are you gearing up to run a production line?

Eric
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 23, 2018, 01:29:01 PM
Eric,

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brass_Machine on May 23, 2018, 02:06:36 PM
Awesome!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 24, 2018, 10:29:24 AM
I knew it was too much of a co-incidence. The chap flogging the Renishaw Probe used to operate this machine at Portsmouth University :clap: :clap:

Not only that - he still has manuals and training materials - negotiations ongoing . . . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on May 24, 2018, 12:23:02 PM
Man that's what I call fall over in Doris' sty and coming up smelling of roses :D
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on May 24, 2018, 01:03:07 PM
Have we done the Balding Beaver joke yet Andrew?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 24, 2018, 03:46:31 PM
Just come off the phone from a long chat with the Renishaw Probe seller - he still works at the Uni . . . .

. . . . 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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 30, 2018, 10:57:16 AM
Still not managed to get the machine transported - seller hasn't mended his forklift yet, and no one can tell me what the machine weighs  :bang:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 30, 2018, 01:14:35 PM
And the good news keeps rolling in  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: chipenter on May 30, 2018, 01:53:43 PM
Was that on ebay last week ? if so they wanted £100 loading fee , I am not surprised it nod not sell .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 30, 2018, 02:58:30 PM
Yes Jeff, and it's been re-listed. He is paying huge warehouse fees and is getting desperate poor chap.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on May 30, 2018, 05:00:57 PM
A word to the wise....

...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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 31, 2018, 12:58:44 PM
I speak as I find, and to be fair the chap has been very helpful to me - he made a special visit to the warehouse to photograph the documentation for me, and try and find a weight for the machine. If it doesn't sell on eBay this time round I've no problem getting back in touch with him, but obviously I will keep your caution in mind Ade.

There's good and bad in all of us I suspect  :med:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 04:46:43 AM
Well after several false starts and delays I got the call 08:30 this morning to say it's loaded to the wagon and on it's way  :clap:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 10:19:18 AM
So rather surprisingly we were able to get Geoff through the dentist slightly ahead of time, and I got a text from a friend just as he was finishing, to say that a big lorry was pulling into the farm and did I need a hand !

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 10:24:12 AM
The firm I used had all the right equipment and the driver certainly knew his Hi-Ab. Superb lorry, nice Toe Jacks,, good skates and a massive hook on the hi-ab that probably weighs more than that Denford Mirac that I mended !

Of course it would never have moved if Geoff hadn't given a push at the crucial time  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: j1312v on June 12, 2018, 11:25:07 AM
 :jaw: Nice Project Matt!!!

I that the ex-uni lathe or the one in the Midlands?

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 01:39:25 PM
Ex Portsmouth University

. . . 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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on June 12, 2018, 02:09:47 PM
Look out for capacitor filter arrays that are centre tapped to ground, but if it has been stood in a damp shed for a few months, it may just be moisture, good luck with it Andrew. A new saga begins!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 02:28:35 PM
I'm rather hoping that the earth leakage is tied in with the controller not showing life - maybe it's internal PSU. Going over to have a gander shortly when my supper has settled  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 04:29:35 PM
So back to it, objective being to get to the back of the controller. It's in a pretty well totally sealed box apart from the Operators Panel (below) and a filtered vent hole to the right.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: j1312v on June 12, 2018, 04:37:40 PM
Sorry Andrew, because of the "ew" at the end all Matthews and Andrews are the same in my head   :doh: don't know why  :scratch:

Good luck finding that earthed bit on the machine, one think that helps is to disconnect, clean and reconnect... :dremel:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 04:41:13 PM
To get better visibility I removed the filter from the vent and shone a torch in revealing  a niffty bracket along the top of the controller stopping it sliding forward.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2018, 04:47:40 PM
So at last the rear of the Controller is revealed, but so is a lot more corrosion, and absolutely no sign of the back up battery  :scratch:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 12, 2018, 11:58:51 PM
Nothing by halves, Andrew! The brown juice, not so nice.  :(  I'm sure you'll have this thing spinning, though.  :dremel:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 05:58:19 AM
Progress report:

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:)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 06:02:25 AM
So with the controller on the bench I attempted to remove all the cards from the card cage - again in places the corrosion defeated screwdrivers and some screws had to be drilled out.

But finally all cards were removed from the card cage - quite a bit of electronics here  :bugeye:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 06:15:21 AM
Now Card-B would appear to be the root cause of all this corrosion.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 06:28:32 AM
I think my next task must be to see if the controller Power Supply works with all the cards out - and if it doesn't then fix it.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Spurry on June 13, 2018, 08:41:08 AM
That's an incredible amount of damage from what looks like a puny little battery.
I wonder how long it took to get to that state...
Pete
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 10:15:54 AM
Well Pete, the sticker says that the battery was changed  18/09/08 so best part of ten years ago . . but which battery are they referring to . . the other one mounted in a sliding drawer over the CRT unplugged reads  3.65 but drops to 0.15 volts when plugged in according to it's monitor points, but they don't seem to go directly to the battery - four wires leading away from the tray into the depths of the controller. To get that (good until 2007!) battery to drop to 0.15 volts I have to load it with 2.2 ohms so obviously those wires are going somewhere else !

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on June 13, 2018, 10:39:55 AM
Pardon my ignorance. Are these cards made by Siemens for a number of different applications or are they custom built for the manufacturer and model?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 11:12:58 AM
Siemens made a range of industrial CNC controls under the Sinumerik name - dependant on the machine tool makers requirements a standard controller crate would be stuffed with more or less goodies.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: NormanV on June 13, 2018, 11:20:53 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"

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 03:03:33 PM
Manual Pulse Generator. A twiddle knob with an encoder on the back to allow manual driving of the axis when not under CNC control

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: NormanV on June 13, 2018, 03:23:40 PM
Manual Pulse Generator. A twiddle knob with an encoder on the back to allow manual driving of the axis when not under CNC control
Oh, that's ok then.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on June 13, 2018, 03:24:12 PM
With the boards appearing to use through hole components, wouldn't it be relatively straightforward (but tedious) job to replace the individual components that are damaged and salvage it if an identical replacement sub unit can't be found?

I presume the battery on the replacement board will be remotely mounted for safety and easier access.   
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 03:38:22 PM
Yes quite feasible. The problem comes if the electrolyte from the battery has destroyed any of the copper traces.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on June 13, 2018, 03:42:54 PM
How about ultrasonic cleaning with distilled water?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 03:55:45 PM
They might end up going through the domestic dishwasher  :lol:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 13, 2018, 04:21:33 PM
Washing it might work, the trouble is you don't know how long for.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 13, 2018, 04:33:59 PM
Years ago we took on the support of all Eastern Electricity Board's white goods distribution system - loads of terminals in shops and offices.

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: )

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on June 13, 2018, 04:50:30 PM
I used to do the same with DEC VT220 keyboards. That, and repairing the silver track on mylar which, due to a design 'fault' used to rub through. RS silver loaded paint was an excellent product.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 14, 2018, 03:58:40 AM
We have company for lunch today so no real play time having done the animals, but I did manage to draw up a sheet metal 'Shelf' in Autocad to replace that bit of aluminium that I'd previously balanced on the bars.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 14, 2018, 11:21:58 AM
Glad to say after a bit of negotiating I've come to a settlement with the German Siemens Sinumerik Card Flogger, and Card-B (my name) and it's daughter memory card are on the way to me - cheeky chappie is charging two set of (expensive) carriage but I bet they arrive in the same box !

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'
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 14, 2018, 03:20:36 PM
So I got a little time this evening when guests had departed to fix the shelf and bars together. I drilled the bars 6 mm and counter-bored them 1/2" so that nothing sticks downwards under the bar to catch you out, and a hex socket will fit in the recess.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 07:24:46 AM
Today's task: Get the Input / Output crate out and find how extensive the damage is.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 07:34:06 AM
Now with the panel out of the way I can reach in and unscrew the four mounting screws for an L shaped mounting bracket obviously made by Beaver rather than Siemens - it's the white bit.

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!)

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 07:38:34 AM
Then it was a case of disconnection of the cable forms but labelling them up first. All came off nicely except one that had a screen earth on a screw tag that was inaccessible without removing the top cover - time to drill a hole I think  :lol:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 07:44:25 AM
So now I can put the I/O unit on the desk and dismantle it to see how extensive the damage is and identify the card part numbers.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 07:51:04 AM
But the corrosion damage to the metal work was actually worse than I thought. No issue, it can all be  grit blasted and painted and will be fine . .


 . . .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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 15, 2018, 08:56:03 AM
Excellent progress so far Andrew. Feels good seeing something being properly restored from an internal disaster.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 12:21:54 PM
Thanks Steve.

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 ??

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 12:25:02 PM
DOH - it's Siemens  :lol: :lol: :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 12:45:09 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.


. . . now where is my 7.5 mm x 3 mm flat bar stored  :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.


. . . now where is my 7.5 mm x 3 mm flat bar stored  :scratch:
you mean this guiderail?
https://www.partsfinder.com/parts/siemens-medical-solutions/1097492
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 05:11:45 PM
Interesting - I've registered and am awaiting a quote ! So how do I find the extrusion that the guides fit ?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 15, 2018, 06:05:48 PM
Had the reply and Parts Source are saying that they can't ship internationally  :bang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vintageandclassicrepairs on June 15, 2018, 07:34:04 PM
Hi Andrew,
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on June 16, 2018, 03:29:31 AM
Andrew, I will be in Seattle for three nights in July, the first to the fourth. Maybe something can be arranged.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 16, 2018, 06:43:41 AM
Seadog that is extremely kind, but I think I'm now sorted as the following paragraphs will show  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 16, 2018, 06:55:22 AM
Then to slit it off the parent angle - I never like using slitting saws, but this went OK, but I made sure it was a very rigid set up. Setting the height of the saw blade I cheated and offered up one of the original square nuts - made life so much easier.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on June 16, 2018, 09:20:21 AM
Ok Andrew. Glad you sorted it.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 16, 2018, 01:13:20 PM
So in that frustrating time 'waiting for bits to arrive' I've been poking around familiarising myself with the various cabinets of contactors, relays, and axis drives - it all looks fairly sensibly laid out and even without drawings it doesn't look too bad to find my way around.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 17, 2018, 01:11:54 PM
A little bit more progress today:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 17, 2018, 04:39:01 PM
Pekka,

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'
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on June 17, 2018, 05:33:31 PM
Those PSU external contacts are normally routed to big red light on the control cabinet and to maintanance system to tell maintenace dude to change the filters..or check esternal cooling air system. Think that overheating and some other stuff trips them. There were more signals on the bus. But that was in S5 industrial PLC, just earlier noticed that much of hardware and numbers looks pretty much the same I was used to see - long time ago.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on June 18, 2018, 05:48:39 AM
Andrew,

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 Ĺ 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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 18, 2018, 07:17:47 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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 18, 2018, 03:43:03 PM
This is the coolant tank that slides under the machine and catches coolant from above. A pipe to a self priming pump sucks it back up and squirts it about at a great rate of knots.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on June 18, 2018, 08:37:51 PM
Truck bed liner.  Make sure they heat it before applying.  My father in law made a mobile steel pool lined with the stuff 10+ years ago.  Still going strong!

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 05:41:02 AM
I realised that getting the coolant tank where it needs to be might be a bit of an issue, as the workshop is a bit cramped now (!) so I made up a bit of wood to act as an analogue of the tank  - much easier and lighter to manipulate - and in fact there is no problem.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 Ĺ AA size lithium batteries and it seems to be only 1.2 Amp hours. 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 11:19:09 AM
The nice man from UPS (Jock) came in after lunch with a parcel from Germany containing the replacement I/O card, Sheradised mounting plate and Umbilical cord that connects the Sinumerik 820T controller to the remote I/O unit. All second hand but looking in excellent condition
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 11:24:03 AM
So with no more ado I marked up the new items with the arbitrary numbers I had put on the old as I removed them, checked the jumper settings on the card and started re-assembling the I/O sub assembly.

It looks slightly better than it did  :ddb:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 11:29:18 AM
Then when I escaped from some neighbours who had dropped in for tea (excuse - I need to feed the pigs !) I was able to start putting that mad octopus tangle of cables back hopefully where they came from and re-fit the I/O sub-assembly from whence it came.

Apart from bally inaccessible screws it went well. I could then start re-wiring the Control Panel ready for re-fitting
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 11:36:00 AM
Now the corrosive fluid managed to put a drip or two on the 9 pin 'D-Type' plug and socket for the MPG Encoder - I've opened up the cable mounted socket and there was not much there to clean out - mainly just external - I've not opened the Euchner Encoder - I'll leave well alone unless it proves not to work when finally I get everything back together.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 19, 2018, 02:55:34 PM
Just goes to show you that something that looks on the outside to be a very nicely kept machine can hide a whole host of problems.

Is all that damage from one little failed battery Andrew or is there another source for the corrosion?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 03:31:10 PM
Just one 8 ampere hour 3.6 volt Lithium Thionyl Chloride  primary battery Pete, but left for best part of ten years to  ooze and rot. :bugeye:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: chipenter on June 19, 2018, 04:09:25 PM
Two pack car paint stands up to a lot nowadays and is available everywhere .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 04:22:24 PM
But doesn't it need extensive air fed masks etc?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Will_D on June 19, 2018, 05:14:54 PM
You've just re-furbed your hydrovane - so no shortage of air!!

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 05:23:50 PM
According to the HSE vehicle paint sprayers have 90 times the chance of asthma than non sprayers:

http://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vintageandclassicrepairs on June 19, 2018, 05:51:26 PM
Hi Andrew,
Would galvanising the tank be an option?
The last lot of hot dipping I got done was very good value

John
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 19, 2018, 06:01:41 PM
It would be an excellent solution but probably pretty expensive, I'll ask around
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on June 19, 2018, 06:24:39 PM
I knew POR prices had gone up, but never realised they're now that expensive.

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 19, 2018, 09:27:07 PM
Hate to say this amidst the high tech solutions, but here, I'd just brush on some Rust-Oleum. I bulit a 13 foot by 4 foot shared coolant tank for two Fadal CNC mills this winter and added a centrifugal cleaner to remove the glass fines (these mills are used for diamond coring thin film coated glass). The coolant used is full oil, not soluble oil. And yes, I brushed it after fabricating, with less than a quart of Rust-Oleum. About $7, U.S. Been going 6 months so far. Paint is as new.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 20, 2018, 03:04:19 AM
That's very interesting Steve. They offer something here called 'combicolour' that sounds good, but whether it is the same formulation that is sold in the US I don't know, I'll give them a call today.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 20, 2018, 06:41:07 AM
Well I've gone with the Rust-Oleum Combi-Color (spelt the American way so maybe it IS the same formulation) in a tasteful  'Steel Grey Satin' not that the colour matters a jot as it's hidden under the machine!

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 20, 2018, 07:20:15 AM
Come on Andrew - we are Mad Modders - MODIFY it  :lol:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 20, 2018, 07:27:32 AM
 Hi Andrew, Rust Oleum here in quart brush style cans is only found in gloss. So I'm guessing your satin stuff is different. Rust Oleum as I know it is a oil based enamel. Word was, in the old days that it contained fish oil. Don't know if that was true. But it was advertised as being suitable for covering rusted steel, iron etc. Always did seem to do well on garden furniture and the like. It comes in spray cans as well, but I have found that the paint coat does not last nearly as well if sprayed. My guess is that it is a different formula.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 20, 2018, 07:37:34 AM
There are other oil based enamels here, minor brands, which claim to be good for rusty metal. Probably similar. I don't have much experience with them. Mainly because I'm familiar with R/O, and long term results with it. But likely most any good oil based enamel tor metal will do.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 21, 2018, 12:45:39 PM
Well oh boy what a day !

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:


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 21, 2018, 02:15:37 PM
Well the day seems to be ending on a high  :clap:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 21, 2018, 02:35:31 PM
Excellent!

This would be the point at which I would consider myself properly 'on the road'.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 21, 2018, 03:32:53 PM
Yes Pete I'm sitting gathering my thoughts in a mixture of exhaustion from today's activities, quiet satisfaction in getting some sense from the controller, and relief that the lathe hopefully now won't be a very large, expensive, and slightly embarrassing door stop  :clap:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: pycoed on June 21, 2018, 03:59:30 PM
Isn't it amazing what Old Speckled Hen can achieve? :drool:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Will_D on June 22, 2018, 04:59:28 AM
A great day Andrew. Thanks for the pig(x)s!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 22, 2018, 06:18:32 AM
You are welcome Will - you have a Saddleback and two Berkshire there  :thumbup:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on June 22, 2018, 01:22:44 PM
What a result on the electronics side Andrew! 40 bar, wow thats quite a lot, is that air or hydraulic, I assume hydraulic, does the machine have a pump on it?
Phil.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 22, 2018, 05:51:21 PM
Yes hydraulics for opening and closing the chuck and advancing the tail stock from a built in biggish pump.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 23, 2018, 04:12:54 AM
Today's task - put the last coat of paint on the inside and top surface of the coolant tank. So having let out and fed the cat, the geese, the chicken and the pigs, and returned the dogs to the house it was painting time.

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 23, 2018, 04:59:52 AM
That was all very well, but I was just packing up and I realised I'd totally forgotten to grit blast and paint the 'Funnel Strips' that fix on to the tank and presumably try to avoid to much fluid being lost   :bang:

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 23, 2018, 06:56:19 AM
Ade, the ironic thing is it will never be seen! It's tucked away under the machine out of sight down that tunnel - the only bit that will show is the broad end, which will have another thick plate sitting on it holding the pump and intake filter.

Actually the finish isn't that bad considering it's grit blasted rust, but not car body standard !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 23, 2018, 10:08:53 AM
Exciting read, Andrew, about the compressor fire and the console coming alive!  :coffee: :coffee:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 24, 2018, 01:21:03 PM
Frustrating day today going round and round in circles :(

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 24, 2018, 02:29:12 PM
Andrew what would be the option for a person who bought such a beast and absolutely had no chance of getting the controller working again? Would it mean a full-on retro-fit or would the machine be basically spare parts?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 24, 2018, 02:50:58 PM
There are firms out there that would repair and reload the controller for a price.

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 )

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 24, 2018, 04:45:44 PM
While I was waiting for the Chicken to put themselves to bed I bolted the 'Funnel Strips' back on the coolant tank. This involved replacing four of the M6 'hank bushes' that I'd had to remove to get the rusty bolts off. Fortunately the ones I carry in stock had the same diameter body, so it was just a case of tapping them in with a mallet and setting them with the special mandrel tool.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 24, 2018, 11:09:25 PM
I feel your pain, Andrew. This winter I worked on resurrecting an MTI dicing saw circa 1990's, all Fanuc boxes, with a bad XYZ servo amp, bad HSSB fiber optics comm card, and NT4 Windows uber-computer with about a 3 gig hard drive and "difficult" controlling software, and little useful documentation. Mfr. no longer in business.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 25, 2018, 09:20:48 AM
Things have progressed in leaps and bounds  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 25, 2018, 02:29:41 PM
So enough of this software malarky - let's get something physical done !

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 26, 2018, 09:25:17 AM
The hunt for the earth leakage goes on!

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on June 26, 2018, 11:45:24 AM
Andrew, I am lost in admiration at your fault-finding ability and sheer breadth and depth of know-how.

I must however sound a note of censure - your boots man, they are a disgrace!

I offer in evidence post #106.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 26, 2018, 12:23:33 PM
You are  NOT the first MadModder to comment on my footwear  :clap:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 26, 2018, 05:02:12 PM
Now of course the mistake Mr Plonker made fitting this fan was to draw 240 volts from one phase referencing it to earth. All well and good if the earth current isn't being monitored by a safety device (The RCD)

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 26, 2018, 05:23:27 PM
I think I've seen one of those in a disused panel at work Andrew. I'll have a look tomorrow.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 26, 2018, 05:35:35 PM
Thanks Pete, I'll wait with bated breath  :thumbup:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 27, 2018, 06:25:16 AM
I spent a bit of time this morning studying the KTK-Mentor DC Spindle Drive power board to see how feasible it is to replace those dodgy capacitors, and indeed try and determine what they are through the 'stuff' they have exuded.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 27, 2018, 12:44:16 PM
It turns out that this lathe was at one time equipped with two probing systems. As well as the tool probe which is hard wired, there has been a Renishaw LT02 optically coupled work probe that sits in a pocket in the tool turret and can measure a work piece.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on June 27, 2018, 03:54:10 PM
You've already found what the cap is... but I was going to suggest it looks a LOT like an AC smoothing capacitor. Sharp fitted them (or one very like them) to all of their 1980s computers... and these days, most of those computers (often having spent years in cupboards and attics) usually blow them fairly soon after being plugged in. As a side note, somewhat oddly, they're connected directly to the mains before the switch.... so an old Sharp can give a scary-sounding  :zap: BANG and a cloud of magic electrical smoke even when it's turned off!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 27, 2018, 04:15:40 PM
Reading up on RFI suppressor capacitors it's actually an interesting and more complex situation than you might imagine.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 28, 2018, 10:26:15 AM
THE RFI suppressor capacitors arrived this morning, so no excuses - replace them !

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 28, 2018, 10:36:47 AM
Then it was a case of un-soldering the old capacitors, cleaning the board up, and soldering in the new. The old capacitors were very degraded, with blobs of I presume solder escaping from the cracks in them. These could not have been left unchanged safely I think.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on June 29, 2018, 03:55:46 AM
Good job with RFI capacitors.

How do those MOV:s feel?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 29, 2018, 04:20:28 AM
Thanks Pekka  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on June 29, 2018, 03:29:57 PM
Knew I'd seen one somewhere, just took me a while to remember where and get round to finding it...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 29, 2018, 04:58:05 PM
What a gentleman  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 29, 2018, 07:01:42 PM
Good man, Pete!  :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 30, 2018, 06:11:54 AM
So with the mention of possible unresolved gear changing problems when still at the University (it HAS gears - news to me  :scratch:) time to see what this beast has by way of transmission.

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 . . . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 30, 2018, 07:16:51 AM
Well I found the spindle encoder ! It was hiding behind the tin work that protects the hydraulic chuck open / closer.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 30, 2018, 12:42:55 PM
A bit more data mining, and I think I've found the Gearbox that the Beaver one is a modification of. It's the MSD-size 353 in the attached  screen grabs of their catalogue.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on June 30, 2018, 01:00:41 PM
Chased that one down.  :clap:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 30, 2018, 05:17:18 PM
I think the combination of digital cameras (iPhone 7 in my case) and Google have made this sort of thing so much easier.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 02, 2018, 09:35:06 AM
Today's foray into the electronics of this beast was to resolve some oddities regarding the pair of 24 volt 7.2 amp power supplies that are housed the the rear left hand cabinet with the turret drive electronics.

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 )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on July 02, 2018, 02:24:45 PM
This machine seems to have a lot of surprises under the hood. The manmade type! Good detective work, Andrew.  :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 02, 2018, 03:33:04 PM
I suspect most machines of this age have a few issues lurking un-noticed, after all it IS 29 years old - almost older than ME  :clap:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 02, 2018, 04:20:37 PM
I think that it would be wise to try and manually drive the Z axis to see how stuck or free it is. By dangling my iPhone into the works I've managed to get a picture of the servo motor name plate - if I'm reading it correctly it's developing 15 Newton Metres of torque at 2000 RPM and taking 25 amps at 150 volt to achieve that  :bugeye:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on July 02, 2018, 04:42:21 PM
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 IC
What vintage is this machine Andrew?
I can remember building power supplies like that 30 years ago, and they were a little dated then.....
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 03, 2018, 01:35:22 AM
Spot on PK, it's 29 years old !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 03, 2018, 03:32:00 AM
This morning, bright and early, I whipped the cover off the Z axis ball screw pulley and tentatively  tried turning it by hand. It turned remarkably easily, but before any significant travel  I needed to move a pile of tooling that came with the machine, and clear as much of the rust on the ways as I could.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 03, 2018, 07:38:35 AM
I managed to grab a few more minutes and cleaned up the ball screw - it's not perfect but perfectly serviceable. Before actual powered use I'll have another go at it.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 03, 2018, 02:29:37 PM
As it happens where I first plonked the transformer is a very handy place. Those bars are tapped M6. So I made an adaptor plate, fixed the transformer and wired it all up.

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 04, 2018, 04:49:35 AM
One thing leads to another . . . .

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 )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 04, 2018, 07:05:32 AM
The Postman (well actually woman - Steve is on holiday!) brought the electronic components for me to be able to continue the repair of the 24 volt Kayser power supply.

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!)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on July 04, 2018, 08:19:43 AM
Andrew,

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 04, 2018, 08:25:07 AM
Thanks for the suggestion. I do have one of those somewhere, but I was somewhat unimpressed - maybe they have improved but mine gives horrid 'fish eye' distortion and is rather low resolution.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 05, 2018, 10:11:21 AM
Bit busy with other things today, so I set myself a nice simple objective - remove the tail stock end panels so that I can clean up round there and inspect the ways for rust and debris.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 05, 2018, 10:30:30 AM
Well the tail stock movement question was easily resolved. I couldn't crank the handle because it has a locking detente - pull the handle out and crank away. But even moving the tail stock fully towards the headstock it is very much in the way for access to those screws behind the way covers   :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 06, 2018, 07:12:28 AM
Determined to get at the bolts to remove those panels, I started investigating inside the tailstock hydraulic cabinet below the controller. There is a wiring duct with a bolt on cover that just might give access to one screw on panel "C". So off it came - sure enough I can see the rear of the hank bush that the bolt goes into, but no way can I undo the bolt itself. OK duct cover replaced, and a clean up inside the cabinet was in order.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 06, 2018, 07:23:05 AM
Having started a bit of a cleaning spree, I thought that I'd clean up behind the tailstock before I wound it back out of the way. Just as well I did - it revealed another panel that just might . . .well you get the idea  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on July 06, 2018, 08:13:04 AM
I suggest Dzus quarter turn fasteners.  They are spring loaded, easy to use, and vibration resistant.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 06, 2018, 08:17:26 AM
Pekka, I agree about the swarf attracting properties of magnets !

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on July 06, 2018, 01:16:34 PM
Because you NEED to know what's behind it ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on July 06, 2018, 04:26:32 PM
And. . It tightens with vibration too!
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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on July 07, 2018, 01:18:23 AM
You clearly just needed special service tool part number X542984-45-92-VW

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 07, 2018, 07:13:52 AM
So carrying on the 'Mrs Mop' cleaning theme I decided to attack the rusty swarf guards. I've wanted to do this for a while but realising that a wire brush on an electric drill was the only realistic way, and also realising that the brushes that I had were far too coarse, I had to wait for finer ones to arrive.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on July 07, 2018, 12:04:13 PM
Nice Job Andrew! It seems like these CNC machines (of which I have zero experience) suffer from the same disease as modern motor cars, the electronics pack up long before the mecanicals wear out, and this makes them an uneconomical repair, because few know enough (me included) to repair at board level, and boards are expensive!. Can't wait to see it spinning! Having said all that, I often find myself repeating an old mantra that was hammered into me when I was an apprentice, "Don't always assume that the fault is complex, and Dont always assume it is in the electronics"! My wife has a mild form of motor neurone malfunction, and the other day her stairlift quit. I tore into it with the AVO, and was baffled.........untill I ticked myself off for not lifting one end of the fuses when I was testing them, and sure enough, an aged fuse failure, quick repair with 5a fuse wire (6.5a fuse) proved that there was no excessive current, and it has worked faultlessly since.
Phil.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 07, 2018, 12:39:12 PM
Thanks Phil, glad the stair lift is working again  :thumbup:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 07, 2018, 03:15:34 PM
I escaped this evening "to see how the 3D printing is going" and managed to clean up the Tool Disk of the Tool Turret - this is the big round thing with 40 mm holes in it that takes the VDI40 tooling.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on July 08, 2018, 06:42:18 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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 08, 2018, 06:44:18 AM
Well the Cetus finished making what it was told to make - pity I forgot to include the location hole in the 3D model  :bang:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 08, 2018, 10:05:54 AM
I went to check on printing progress of the Mark 2 VDI40 blank plug and was amused to find that the Cetus 3D printer had a passenger - a grasshopper had (presumably) hopped onto the build plate and was taking a ride - remember in this printer design the build plate traverses back and forth - little chap was lucky that I hadn't turned the plate heater on  :lol:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 08, 2018, 04:42:36 PM
So coming out to inspect the finished (third) plug I thought I might as well see if I could set it going overnight to print a pair side by side. They just about fit on the build plate, so I set it going and wanted to wait until it had at least begun the second ones first layer.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 09, 2018, 05:31:53 AM
Well the overnight run printing two plugs at the same time came out a bit of a mess. The left hand one must have detached itself from the build plate shortly after I left it, resulting in a birds nest of PLA in pretty pink  :bang:

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:)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: John Swift on July 09, 2018, 06:57:44 AM
Hi Andrew

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RotarySMP on July 09, 2018, 10:06:01 AM
You got lucky with only a birdsnest from your 3D printer. Whenever I leave mine alone, the filament ties itself into a cloves hitch on the spool, and then the Z Axis climbs itself up the filament untill the Z nuts are free. Causing birdsnest plus need for realignment and leveling.
Mark
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 09, 2018, 10:40:57 AM
John, when the faulty 24v psu was in it went to nearly 35 volts. The regulator is fine at the moment, it's just that talking to a chap who used to be involved with these lathes, apparently it's a common point of failure. Anyway nicer to have a separate 5 volt supply off the mains rather than draw up to 3 amps off the DC.  (24-5 = 19 volts drop at maybe 3 amps is 57 watts just there alone and the 24 volt supplies are regulating down from 38 volt to 24 at 14 amps - there's another 196 watts !)

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 )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 09, 2018, 05:11:22 PM
Time to install the new power supplies, first I made up an adaptor plate to mount the DIN rail clips on the back of the 24 volt supply, then I removed the remaining old linear one to make way for the new.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 11, 2018, 05:20:08 AM
Well at last I've received the drawings for the wiring, so a bit of printing out and studying called for today  :coffee:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 12, 2018, 04:10:10 AM
OK time to bite the bullet and put the controller back in - a bit fiddly, but far easier than taking it out - at least now all the connector retaining screws work, rather than having to be sheared off due to the corrosion !

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 12, 2018, 04:26:36 AM
Time to grit my teeth, and power the machine up  :bugeye:

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'

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on July 12, 2018, 01:16:25 PM
All door lock sensors functional, Andrew?
Limit switches?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 12, 2018, 04:17:47 PM
Amazingly there are no interlocks on the cabinet doors, and the sliding door giving access to the actual lathe not only has an interlock, I can read it as a logical 'bit' coming in and changing as I open and close the door.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 14, 2018, 11:49:20 AM
So Hydraulic Digger Pump replaced, earth shifted and now back able to play  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 14, 2018, 02:33:59 PM
Well, progress through adversity  :ddb:

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 !!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on July 14, 2018, 10:09:15 PM
Finally!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 15, 2018, 05:26:13 AM
After more 'going round the houses' with a meter and wire sniffer (*) I've eventually deduced that those two small relays are nothing to do with monitoring the 24 volt power supply  :bang:

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 15, 2018, 05:50:35 AM
 :clap: :clap: Well guess what I've found  :clap: :clap:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 15, 2018, 11:53:01 AM
Back from entertaining relatives at the Pub, and straight back to the workshop to chase that fault. Lucky I was the driver, so my head is quite clear on only Soda and Lime !

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 15, 2018, 01:58:11 PM
Well no point in putting it off - remove board - replace capacitors - return board to it's rightful  place and switch on keeping fingers crossed.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on July 16, 2018, 04:11:29 AM


Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 16, 2018, 05:24:09 AM
Thanks Russ

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on July 16, 2018, 06:10:11 AM
Sort of points to the possibility that some other accesory, now removed, was connected between 99 and 100 to modify the sequence, tracing the two non standard wires may give a hint!
Phil
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 16, 2018, 10:59:23 AM
OK Turret Initialised  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on July 16, 2018, 11:16:53 PM
Just catching up....exciting day yesterday!  :thumbup: :clap:

An you're moving right along today, with all axis moving. Good man!  :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 17, 2018, 11:22:27 AM
As is the way with these things it's one step forward, one back !

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 18, 2018, 04:09:31 PM
Well an extremely frustrating day today  :bang:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on July 18, 2018, 05:13:56 PM
Andrew, I'm curious.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 18, 2018, 05:51:13 PM
You have to remember that this machine has sat un-powered and unused in two locations over the past 10 years. Things deteriorate, connections corrode and problems are bound to emerge as it is brought back into commission.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 19, 2018, 03:31:51 PM
Another day going round in circles, but I've reached a tentative conclusion. But before I reveal that I took a break from diagnosis (to preserve sanity!) and did some metal bashing.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 19, 2018, 03:48:56 PM
Before the tin bashing I had come to the suspicion that the drive fault that is being reported is actually the FXM-3 Field Coil current driver - clue - it's little red light was not on and should be !

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RotarySMP on July 20, 2018, 06:42:50 AM
How does a farmer get to be an experienced Mechatronic engineer? You are very good at this troubleshooting.
Mark
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 20, 2018, 08:07:10 AM
Answer: he didnít start life as a farmer!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on July 20, 2018, 01:41:14 PM
I did 10 years of S5 and S7 and always needed some support manauals! No matter if the printed probram was only 150 pages of ladder/blocks or 10x that, there were plenty os stuff.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 21, 2018, 04:58:23 PM
Another jolly old day wandering aimlessly around the maze  :bang:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 21, 2018, 05:21:25 PM
Now the oddity about the tool change failing if it involved an anti-clockwise turret rotation sort of fitted in with my observation that if manually unlocked and rotated by hand it was more difficult in one direction than the other. There seemed to be a slight bias aiding turning anticlockwise. Maybe the servo null point needs adjusting.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 22, 2018, 07:21:38 AM
Another interesting journey this morning !

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on July 22, 2018, 10:04:01 AM
Is there a continuous magnetic field in the area? Something magnetized?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on July 22, 2018, 11:17:51 AM
I got the impression that this proximity switch has open collector output, they can be ORed, that (or other output) would burn totem pole output. Also I got impression that it is and inductive sensor, those are not that sensitive to magnetic fields (HAL is a different animal).

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 22, 2018, 01:18:07 PM
Well chaps what I SHOULD have done is disconnect the three wires and test it 'in situ' using my Proximity Sensor Tester, that I had completely forgotten that I had until a lull in the music this afternoon  :bang:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 23, 2018, 06:46:49 AM
 :thumbup: :thumbup: Well developments  :thumbup: :thumbup:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 23, 2018, 12:25:57 PM
So to celebrate I at last got round to changing the hydraulic solenoid 'Tell Tales' - originally there was a DIN 43650 socket fitted to each hydraulic solenoid valve, with a 24 volt 'Pea Bulb' to indicate the state of the valve.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on July 23, 2018, 01:01:03 PM
We have those on some of the demo robots at work. They ain't half handy when something doesn't move when you tell it to, cuts down the diagnostic time drastically.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on July 23, 2018, 03:20:00 PM
There used to be...or maybe still is a thin washer kind of socket that had a lindicator LED and you could just slide them between solenoid and socket.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 23, 2018, 04:40:54 PM
That's a neat idea  Pekka :thumbup:

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 24, 2018, 09:22:26 AM
A couple of developments today:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on July 24, 2018, 02:06:27 PM
I'm just getting caught up with this thread.
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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 24, 2018, 05:15:50 PM
The Dog mounted in the turret is spring loaded, and the dog mounted on the tool is fixed axially. As the control selects another tool with a 'T' command, the tool disk moves forwards, rotates to the new tool, then clamps back engaging the dogs.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 25, 2018, 06:36:33 AM
Adrian the ParcelForce man brought my RS Components order of the extra illuminated DIN 43650 sockets for the three extra ones I'd 'discovered' the other day, so I set too with enthusiasm. Now these devices are tucked away in a dark and difficult to access corner. First original one came off fine and got replaced. Second one was obscured by a hydraulic pipe - no big issue, slacken the fitting and rotate it a bit out of the way. It was when I was disconnecting the cables on this one that the light bulb went on. Hang on, these are wired differently, the cables don't go to terminals 1 & 2 they go to 1 &3 - what gives :scratch:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 26, 2018, 02:12:57 PM
I dusted off the GoPro camera and filmed the machine moving X & Z axis's and doing tool changes - a little diddy program I wrote just to see how you enter code into the controller and exercise the machine a bit.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on July 26, 2018, 05:22:32 PM
Looking good.
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 26, 2018, 05:49:37 PM
I tried altering the field of view of the GoPro and shot a walk round tour of the lathe - not sure if it's any better  :scratch:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 27, 2018, 06:43:12 AM
The cable marker 'flags' and an appropriately fine 'Sharpie' marker are now here, so I cleaned off the sticky mess that was the previous labels and applied the flags.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on July 27, 2018, 10:46:26 AM
When I'm designing hydraulic machines, I specify Turck polyurethane cables with moulded on DIN 43650 ends.  I spec both a light and an MOV.  The whole thing is much cheaper than good cable plus labor for field installed connectors and is actually watertight.  AND field installed 43650's totally suck!
They also make ones with two lights for switches.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 27, 2018, 10:53:33 AM
The Field Coil Driver PCB turned up curtsy of the UPS man Mac - motor specifies a maximum voltage for the field coils of 170, I really wanted to set the system by current but the motor plate carries only the max voltage - OK they are related, but the actual current is pulsed DC so not exactly by Ohms Law.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 28, 2018, 06:27:55 AM
So now I am able to actually do things with the machine it's time to get to grips with the programming. The Sinumerik input method at the console is not exactly intuitive. For example this morning I spent two hours finding out how to delete or edit previously input code. I suppose really it's intended that code is generated off the machine and uploaded, but the controller does have quite a comprehensive graphical set of guides for the various G & M codes

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 29, 2018, 12:52:33 PM
I've had an intermittent fault on the Tool Turret for a while - it seems to come and go but I convinced myself that it was heat related. Manifests itself as the SMCC card and or the 820T controller reporting it is at a wrong tool location when a tool change is commanded. Leave it alone for half an hour and the fault clears only to come back later.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 29, 2018, 02:53:31 PM
Not surprisingly it turns out that these  proximity sensors are modular. After much unscrewing the defective module came out revealing another part number. I've traced one to eBay in Germany and am waiting confirmation of postage charges, but it does mean that if the module isn't available, I can get a two or three way version and rob it for spares
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 30, 2018, 03:37:41 AM
This morning I repeated the test on the individual Proximity module under slightly more controlled conditions, and sure enough it's still faulty. Loaded with 4K7 ohm / 5 mA it takes a matter of seconds before it ceases to work - specification is I(max) of 125 mA. Dowsing it in IPA and blowing with an airline to cool it by extracting the latent heat of evaporation it returned to the working state, then again rapidly failed.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 30, 2018, 11:08:12 AM
Chap in Germany has now accepted my order for the Balluff proximity module and is posting today, so hopefully later this week it can go back together. Actually I bought two, so one to put in the spares box :thumbup:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on July 30, 2018, 12:55:11 PM
I reckon that's why the turret wasn't working properly Andrew - it couldn't see what it was doing :lol: :lol: :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 30, 2018, 02:10:56 PM
Very Droll  :clap:

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 !!!!! )


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on July 30, 2018, 04:38:03 PM
I guess its karma paying you back :thumbup:.

BTW why not a LED strip light like the Traub? Better lighting for the obligatory videos when the project is finished.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 30, 2018, 04:48:02 PM
At the moment NRML I cannot even get the fluorescent one out never mind installing an LED one  :palm:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 31, 2018, 06:07:18 AM
This morning I rubbed down the tinwork, filled a few of the more obvious blemishes, and sprayed a coat of Machine Enamel from Craftmaster Paints in Cambridge in RAL9010 'almost white' - the stuff left over from painting the Denford Mirac - on the insides and undersides. Hopefully I can get the outsides and top sides sprayed this afternoon.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 31, 2018, 08:31:08 AM
As I had hoped I was able to get the other sides of these items sprayed after lunch.  Not perfect as I got a small run that I had to brush out, and will need flatting before I start on the top coat - might have to let it harden for a day or two to be able to do the flatting without tearing the paint.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RotarySMP on July 31, 2018, 10:44:53 AM
Are you really considering rubbing out a paint run on internal sheet metal covers within a CNC lathe enclosure? Just turn stainless once and the stringy birdnest will thoroughly rub it out for you :)
Mark
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 31, 2018, 11:11:26 AM
Mark

If you're doing a job you might as well do it properly. I was taught to take a pride in my work  :med:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 01, 2018, 02:37:08 PM
Overnight the paint had hardened sufficiently to flat down the blemishes and when it was delivered spray the inside and undersides with the RAL9001 creamy colour, which seems to be quite a good match to the original - just looks cleaner !

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JerryNotts on August 02, 2018, 04:19:42 AM
Andrew,
What film thickness meter are you using. I presume you are  using wet paint, not powder coat.
Jerry
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 02, 2018, 07:30:06 AM
Jerry, it's a rather nice device made by Sheen that I must have bought yonks ago. I'm ashamed to say that when I dug it out of the cupboard the 9 volt battery was dated 2004 - I always scratch a date on batteries in equipment when I install them - fortunately this one hadn't burst and actually was still measuring 8.5 volts, but obviously I changed it.

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 !




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 02, 2018, 10:28:11 AM
A diddy program Steve is just an off the cuff small bit of code created usually at the console to test some function or feature - in this case the Tool Turret tool change reliability.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vtsteam on August 02, 2018, 10:41:30 AM
ah, a test loop  :med:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on August 02, 2018, 07:14:03 PM
I'm trying to understand what bits of the turret actually slide/turn. Looking at your second encoder wheel picture in reply/post 240, I'm confused.

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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 03, 2018, 02:49:33 AM
MC there are two Hirth couplings. One with half on the body of the turret, and half fixed to the rear of the tool disk. The second has half connected to the central shaft and half connected to the belt drive system. They are arranged so the when one is engaged the other is disengaged. So the hydraulic cylinder pushes the tool disk and shaft to the left freeing the disk to rotate and coupling it to the servo motor drive. A combination of the SMCC card, the 820T controller and the Simodrive servo cards rotate the turret to the demanded tool and the hydraulic cylinder then locks the front Hirth and disengages the rear one, leaving the servo motor free to drive the powered tooling.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on August 03, 2018, 06:43:29 PM
It makes sense now.

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..
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 04, 2018, 02:04:20 AM
Yes Moray, item #17 is a co-axial hydraulic cylinder that is double acting, operated by a two way spool valve.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JerryNotts on August 04, 2018, 03:33:28 AM
Its important to not become too hung-up on what you might see in patents. For many years I worked in a (British) company that patented almost everything that was thought of in its extensive laboratories. Part of the philosophy in that company and other R&D based companies was to issue so many patents for similar things that competitors found it difficult to work out which patents might apply to the item in front of them. Of course every patent could be backed-up by records showing how, if callenged, the patent was arrived at.
Jerry  :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 04, 2018, 03:50:36 AM
I agree Jerry, but in this case nowhere else are there any drawings or descriptions of how the thing worked, and I've talked to three people who worked for Beaver maintaining these turrets. Even then drawings weren't available and they just had to muddle through and do what they could.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 04, 2018, 11:59:51 AM
I spent this morning altering a Post Processor for FeatureCAM to generate code suitable for the lathe. Not there yet but distinctly 'on the way'. I also spent some time investigating the commands for the Powered Tooling discovering little quirks like:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 04, 2018, 03:00:38 PM
I decided to have another go at the cut out for the catch on the Tail stock Door. Remembering how well lead free solder works with galvanising I soldered up the 'over cuts' where he'd been a bit reckless with his cutting disk, then flatted it down with a sanding disk.

Now at least the remaining blemishes are hidden by the rim of the catch
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 04, 2018, 05:07:20 PM
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 05, 2018, 04:39:17 PM
ish !

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on August 05, 2018, 11:28:01 PM
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 ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on August 06, 2018, 05:11:23 AM
Hi there, Andrew,

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!!! 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

"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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 06, 2018, 06:06:03 AM
Pete the dogs seem fine together  :thumbup: Remember we frequently have people with dogs staying in the cottages, in fact the other one has two at the moment, so three extra dogs on site !

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 06, 2018, 12:15:29 PM
Milton,

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: DICKEYBIRD on August 06, 2018, 02:22:31 PM
Thanks a lot Andrew, I believe it's finally starting to sink in.  When I finish the latest homing sequence update, your tutorial & actually keying it in at the lathe a few times should sort me out! :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 08, 2018, 11:23:34 AM
It's been a bits an bobs day for the last couple of days, chasing up and investigating things. A few positives:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 08, 2018, 01:55:14 PM
I've been having trouble with the tail stock. It is clamped to the bed by spring loaded clamps biased in the 'clamped' direction, and un-clamped by two small hydraulic cylinders. M51 comand clamps it, and M52 unclamps it. In addition there is a pressure switch on the hydraulics that reports the clamped state back to the controller.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Will_D on August 08, 2018, 04:22:40 PM
I am so impressed with this thread Andrew. Yout rabnge of skills/knowledge is oustanding.

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!!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 09, 2018, 11:50:56 AM
Will-D those two Berkshires are off on a one way journey early Monday so don't tell them !

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: modeng200023 on August 09, 2018, 03:04:05 PM
If you go on improving the machine like this your friend will want it back!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 13, 2018, 04:41:34 PM
Well I'm STILL going round the houses trying to get 'spindle orientation' working.  :bang:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on August 14, 2018, 12:40:21 AM
So, the rubber duck approach : explain to us ducks exactly what you are doing, what you expect to happen, and what does happen.
Sometimes the act of explaining it helps you to realise the issue.
Or, less likely, one of us may see the flaw.



Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 14, 2018, 02:05:30 AM
It also helps to vent my frustration Russ !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on August 14, 2018, 06:23:09 AM
I agree fully with your method Andrew, go away and do something else that keeps your mind busy, and let the unconcious computer have a go at the problem. You can only get so far in one session, and then you start to get frustrated and think yersen round in circles! Take a break. Earth shifting sounds fine, but always leaves me with a flasback just as I am falling asleep, I am back on the digger, and it has just gone beyond the point of no return, and is going over!
Phil
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 14, 2018, 08:13:39 AM
Mostly sorted Andrew..you are becoming a leading expert on the Beaver machines  :D I'm not far behind you having re furbished and repaired a few in my time.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 14, 2018, 08:28:23 AM
On the spindle orientation..a very odd fault..as you would think the control would alarm if it wasn't in the correct position?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 14, 2018, 12:09:51 PM
Welcome to the forum, why don't you post a bit in the Introductions section and tell us a bit about your projects ?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 14, 2018, 04:27:51 PM
I decided that at least I could easily solve the issue with the FXM-3 Field Coil DC Drive Card overheating by adding a fan - actually easier than making a larger, but remotely mounted heat sink, which was option 2. The heat sink is up at 415 volts so needs to be away from fingers!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 14, 2018, 05:29:52 PM
Thanks Andrew, yes I will do an introduction had forgotten about that..  :Doh:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 14, 2018, 05:45:08 PM
John, I'm putting in code copied directly from the Beaver hardware manual, also from a set of Beaver programming course notes that I have. I'm doing it under MDI, and also running it from a small program of the same code loaded into the machine, all with the same result.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 14, 2018, 07:11:18 PM
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!

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 15, 2018, 08:07:00 AM
So having picked up a load of grass seed from the merchant early this morning, I was able to get on and fit the fan.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 15, 2018, 09:42:40 AM
It's funny I was going to mention if there could be a difference in the PLC software or the parameter set...my Partsmaster parameters  from new where changed at the college to add/remove options over the years but no records were saved..
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: David Jupp on August 15, 2018, 12:05:59 PM
http://forums.mrplc.com/index.php?/topic/24709-alternatives-to-step-5/
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 15, 2018, 12:13:47 PM
Thanks for that David, but the available one of those is £600  :bugeye:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 15, 2018, 12:28:47 PM
So Andrew is the cooling fan on the FXM-3 a part fix or can you run the motor at full current now..? I've never seen one of Mikes boards but looks very similar to the standard issue FXM-3..are there any advantages using Mikes newer board?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 15, 2018, 01:04:59 PM
Mike told me it was designed for a maximum of 3.5 amps, so it is on the limit with the size of motor in this beast. But he also told me that of the boards he made, he only had transformer failures, never the thyristor. So having re-set it at 3 amps it's still on the conservative side of the spec, but I far prefer electronic to run cooler than hotter!

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 15, 2018, 01:42:40 PM
Thanks Andrew that's good to know.. I'm not sure what amps the original board was rated at?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 15, 2018, 02:00:38 PM
The same 3.5 amps - it uses the same thyristor - a BTW68-1200n . There is an upgraded one the BTW69-1200N that is OK for 50 amps , but of course it's the dinky little heat sinks that cause the issue.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 15, 2018, 03:29:31 PM
My Partsmaster has the same electronic cabinet as your TC20..same spindle drive and Siemens servo rack with the same style AC servos.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 16, 2018, 01:14:14 PM
One of the modules in the Sinumerik 820T controller that could conceivably be a cause of the angular positioning fault is the 'Measuring Card' - unlikely but possible. Now I have no issue with buying spare cards as shelf spares if the price is right,but these things have been fetching several hundred pounds on eBay, and some sellers asking  over £1K  :bugeye:

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 18, 2018, 05:53:08 AM
Today the Post Man brought a mystery package from deepest Hampshire - odd - not ordered anything from there. Well my face split into a grin when opening it I found two 25 mm shank index-able lathe tools kindly sent to me by Pete W. - gosh Pete thank you so much - those will be extremely handy :thumbup:

 :mmr: :mmr:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on August 20, 2018, 06:09:32 AM
You're welcome, Andrew,

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!! 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 20, 2018, 09:03:52 AM
I have holders that will accommodate both left and right handed cutters, you just have to remember to rotate the chuck the right way for the cutter you are using as you mount right handed ones inverted. The holders differ in whether the clamp press the tool up or down.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 20, 2018, 09:24:12 AM
For those of you wanting to practise before you apply to Bletchley Park to join the Cryptology course  I'm attaching the 'Sub Program' or subroutine that does most of the probing.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 22, 2018, 12:39:04 PM
Today I got more parcels from Germany  :thumbup:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 22, 2018, 12:47:25 PM
So having totally failed to unscrew some hydraulic fittings this morning I returned to the Beaver for consolation and set too with the Tool Probing Software.

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 22, 2018, 01:14:36 PM
Here is the Video - Tool Probing Tentatively at very low feed speed !


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on August 22, 2018, 02:15:01 PM
Looking good! Iíve been watching eBay boards for a while they can be quite expensive. Our lathe has been sitting for a while it did work but now just says ďHost control initializingĒ but everything passes there is a guy that is suppose to look at it in the near future that has worked on them before so fingers crossed!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 23, 2018, 07:02:24 AM
Thanks Tom  :thumbup:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 23, 2018, 11:25:03 AM
Then I got really brave - or maybe reckless - and tried a Type 4 tool. In fact this was because I wanted to define an offset for the 'second edge' of the parting tool so that dependant on which offset you choose, the  kerf comes from the part left in the chuck (D7 offset) or the bit you've turned (D17 offset). This controller lets me define up to 99 offsets, so with twelve positions in the turret there are lots of options.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 26, 2018, 05:26:16 AM
Having got a bit more understanding about the tool setting process, I've spent some time creating a 'Tool Crib' in FeatureCAM that replicates the tools so far installed.

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 !



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Will_D on August 26, 2018, 05:59:17 AM
Nice clogs!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 26, 2018, 06:03:48 AM
Yes Will I must find some simple video editing software - don't have any atm !  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 26, 2018, 04:38:45 PM
The spindle sound good considering it's been sat for 10 years or so  :headbang:

Under the finish tab in Feature Cam it has finish point and start point..I presume you have tried that with no effect?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 26, 2018, 05:18:43 PM
That might be on a later version perhaps as I'm not aware of those options. Can you confirm version and put up a screen grab of the feature ?

I'm running FeatureCAM 2007 V 13.1.0.28
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 26, 2018, 05:42:12 PM
It's an old version 2004.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 26, 2018, 05:48:52 PM
Managed it..brain fade again  :doh:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 26, 2018, 06:02:46 PM
. . . ah that looks interesting. Also interesting that your drawing does to same over enthusiastic finishing pass.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 26, 2018, 06:13:59 PM
I'm pretty sure the setting are the same in later versions I don't think FC has changed much even on the latest version..I also noticed the x position going below center line but it leads in at an angle and only touches the work piece at the center line by the looks of it...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 27, 2018, 03:14:46 AM
John, you are entirely correct - this feature IS in the 2007 version that I have, BUT - up bright and early to test it out (well actually up bright and early to get the bins out - yes they collect on a Bank Holiday!) and the results are not at all what I expected.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 27, 2018, 03:56:28 AM
OK problem solved  :thumbup:

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:



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on August 27, 2018, 05:25:25 AM
That is very nice. Tool path looks nice with 30 degree approach angle and sounds logical.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 27, 2018, 07:08:36 AM
No nor do I Pekka - it's very odd  :scratch:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on August 27, 2018, 09:39:03 AM
You are welcome Andrew  :nrocks: Probably with it being a different version of FC but mine defaults to 30 degrees lead in and lead out on turning and milling. You can set up all these things before hand by using the manufacturing tab then the machining attributes tab  :headbang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 27, 2018, 03:59:47 PM
Oddly John, when I go into the Manufacturing -> Machining  tab it is set to default to 30 degrees, so goodness only knows how it got set to 0 degrees when processing that simple dome . . . life is full of these idiosyncrasies  :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 30, 2018, 02:59:59 PM
Time to re-wire the lathe and the associated bits of infrastructure wiring !

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.



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 01, 2018, 07:58:59 AM
Sounds like a shop tour coming on..great to see some British made machines are still making parts..
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 01, 2018, 10:47:38 AM
Today the bits arrived to mend one of the Powered Tools. I'd diss-assembled it a few days ago, revealing a pair of rather nice opposed pre-loaded taper roller bearings taking the main load, and a needle roller bearing supporting the drive shaft, with seals at both ends.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 01, 2018, 10:49:31 AM
...continued
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 02, 2018, 06:04:38 AM
I had a free couple of hours this morning, so I decided to attack the second Baruffaldi Powered ER32 collet chuck. I'd taken the precaution of ordering two sets of oil seals and needle roller bearings so should have been equipped for war !

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 . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 02, 2018, 09:15:00 AM
Looking at the nut and the cut-out at the top of the thread, it looks to me as though peening is the correct method of locking it, just not done very neatly in this case.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 02, 2018, 11:54:02 AM
I think it's been reworked previously, and as you say the peening has not been done very neatly. The nut is 28 mm x 1 mm pitch, which doesn't seem to be a common one (other than on scooter clutches !). I'll probably re-use the original, but re-making would be reasonably easy.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 02, 2018, 12:04:00 PM
All you need is a CNC lathe and it'd be a doddle... :Doh:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 02, 2018, 12:30:25 PM
It's actually a simple enough job on a manual lathe and mill (had to do one on the Tractor Flail Mower rebuild) but I'll probably re-use the original.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 02, 2018, 12:34:13 PM
"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."

You should have put your overalls on then... :)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 02, 2018, 04:54:10 PM
Driven out of the house by Vanity Fair on the TV I took refuge in the workshop and re-assembled the powered tooling.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 04, 2018, 10:03:03 AM
The other day when I was experimenting with threading cycles, the motor was accelerating to max revs and decelerating, all very impressive, but doing it a few times I managed to trip the 32 amp three phase breaker in my workshop distribution panel. Also feeling the 2.5 mm 5 core 'SY' cable that fed he lathe, it was distinctly warm  hot  :bugeye:

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 )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 04, 2018, 10:20:39 AM
It always amuses me when making PG threads, which I've had to do a few times for Commando Plugs & Sockets, that all the dimensions are metric, until you come to the thread pitch, which is 'turns per inch' - 16 in  this case  :ddb:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 04, 2018, 04:57:54 PM
For peace of mind I ran the threading program several times over and over, then measured the temperature rise of the 6 mm 5 core SY cable, and the 4 core SWA cable. Both had gone up by only 7 degrees, so unless I go into mass production of widgets 24/7 I reckon I'm in the safe zone. Both cables are rated up to 70 degrees C and they only got to 30.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 05, 2018, 02:23:59 PM
Indulge me, and bear with me as I try to sort a few things out in my head regarding tooling  :scratch:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 05, 2018, 02:35:07 PM
Maybe their interpretation of what is left or right handed is not the same as yours or mine?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: DICKEYBIRD on September 05, 2018, 03:12:55 PM
It should be that M3 causes the spindle to rotate clockwise as viewed from the rear of the spindle or chuck & M4 the opposite direction.

I know you British folks drive on the left side of the road but do your clocks run backwards :bugeye: as well?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 05, 2018, 03:54:00 PM
Milton, this lathe, and other ones I had (Traub, Denford Mirac, etc) , definitely rotates clockwise looking from tailstock to chuck for an M03

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 05, 2018, 04:00:22 PM
I agree with your interpretation of handedness, it's the standard as far as I'm aware. It seemed like that might be a possibility without having to use any brain power (reducing by the day) to analyse what you'd said.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 05, 2018, 04:35:26 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 Mirac

. . . .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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 05, 2018, 05:51:41 PM
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....
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 Mirac
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?

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 06, 2018, 04:06:18 AM
Just to convince any doubters, myself included, here is a little video showing an M03 starting the spindle !



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on September 06, 2018, 05:52:12 AM
No there isn't...

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 06, 2018, 06:36:06 AM
Strange - it's marked as Public  :palm:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on September 06, 2018, 09:37:22 AM
Love the spelling  :doh:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 06, 2018, 09:51:32 AM
Yes it is a bit hit and miss isn't it. I've noticed that on several of the Beaver documents
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 06, 2018, 02:36:34 PM
Although when I set the machine to cut a thread 'in the air' it appeared to be cutting correctly, now I've been brave enough to cut metal (and actually mount a threading tip, and measure it's offsets, it is obvious that all is NOT well. It looks to me as though the spindle rotation is not synchronised to the Z travel. Presumably the controller should wait for a reference point in the rotation before firing off the Z movement whereas the two look to be asynchronous to me.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on September 06, 2018, 03:14:09 PM
Is it supposed to be a  LH thread?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 06, 2018, 03:51:05 PM
Nope !

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on September 06, 2018, 04:56:27 PM
So there is a dichotomy beween simulation and the actualisation.

I suspect that beetroot juice has got in the gigglilator sprocket and is confolunding the fundamole.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 07, 2018, 07:10:30 AM
OK I finally think that I've gone MAD  :bugeye:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 07, 2018, 07:34:24 AM
I've seen this..... oh bugger, where have I seen this?.... I vaguely remember a discussion about threading with rear toolposts in the days of turbocnc... 

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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 07, 2018, 07:40:06 AM
M3 spindle anti clockwise looking from the tailstock end..and the tip facing down to the floor..basically a manual lathe with the tool post rotated 180 degrees around the chuck..a throw back from when early cnc lathes which were modified gap bed lathes..the swarf could then be fired down into the trough so it was easier to leave the machine running without the operator needing to clear the swarf.

The Hitachi Seiki 4nE11 was this same configuration.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 07, 2018, 07:42:08 AM
As the Beaver is running clockwise in M3 upward facing tools all the way.
 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 07, 2018, 07:53:06 AM
SOLVED  :clap:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on September 07, 2018, 08:48:03 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...



Sent from my SM-G965F using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.








Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on September 07, 2018, 11:03:45 AM
All this testing is producing masses of swarf
Surely a smaller bit bar, or a bigger nut would reduce the masses...  :)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 07, 2018, 11:18:59 AM
I know this sounds silly, but the hydraulic chuck jaws that I have on only close down to about 20 mm so I am using 25 mm (well actually 1") stock for testing. I do have soft jaws to fit but don't want to waste them. The jaws fitted are hard jaws.  :palm:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 08, 2018, 06:26:47 AM
After much digging about in the inner workings of the FeatureCAM Post Processor I managed to prove that the program was outputting an 'absolute'  depth of thread rather than a 'signed' value as required by the Sinumerik 820T control. But I also realised that actually I could determine if when the threading cycle was entered it was an internal thread (requiring a positive depth), or an external thread (requiring a negative depth) by testing an internal variable called <OP-TYPE> that I discovered.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 08, 2018, 07:16:05 AM
That's why i like Featurecam..editing posts is really easy..the whole cam package is built with machinists in mind  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 08, 2018, 09:31:07 AM
Yes I haven't gone that deep into pp editing..I know just enough to alter a standard post for 3 or 4 axis.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 08, 2018, 09:58:47 AM
These may help
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 08, 2018, 12:24:36 PM
Great..I hadn't realized these manuals were out there..now I can learn properly and not by my usual method of trial and error  :Doh:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 09, 2018, 08:42:13 AM
Pekka,

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












Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on September 09, 2018, 08:52:42 AM
Nowadays I am next to useless on S5/S7 et.al. I should send a colleque. She is younger, smarter and she has S5 on laptop, but she has two teens, another is a rally driver and another is pricess....should be a lot of fun.

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 09, 2018, 09:02:17 AM
At least you have done it in the past, I've never even seen it running  :bugeye:

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on September 09, 2018, 10:32:01 AM
I used program and start machines, mostly with S5/S7 and mostly in ladder. But that was long time ago and there was always someone to call, beacuse there were leasto of 20 of us at any given time. Therefore my knowledge is very limited and spesific. But I could ask some pointers from the new blood.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 09, 2018, 11:11:29 AM
Pekka that would be very kind.   :thumbup:


Presumably with the right software PG 675 / 685 / 720 or 740 would work ?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: David Jupp on September 09, 2018, 01:57:15 PM
Where I used to work we had S5 PLCs controlling some plastic compounding equipment.


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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on September 10, 2018, 05:53:22 AM
Uhh. it is actually now bigger problem than it used to be. I asked the SW engineers and they all said that it is nearly impossible to get any of the S5 application program running on modern/latest laptop.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 10, 2018, 06:57:28 AM
Pekka, I have a working Panasonic Toughbook CF-50 running XP with a real RS232 port - in fact I loaded OPERA browser on it only this morning as  Chrome, Firefox etc no longer support XP

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on September 10, 2018, 08:05:46 AM
For serial communication, we needed
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 10, 2018, 04:15:48 PM
I spent some more time today trying to investigate why I can't get the Renishaw optically coupled probing system working.

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.



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 10, 2018, 04:24:08 PM
Now from previous work I had proved that the OMM is transmitting an IR 'wake up' signal, comprising a 250 millisecond burst of 125 uSec period pulses every second. I did this by cobbling together my own IR receiver.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 10, 2018, 04:47:26 PM
So the next job was to remove the electronics and power them up on the bench. The MI12 supplies 10 volts to the OMM so that's what I gave it. To my surprise although the power LED came on, the Yellow 'wake up' LED didn't. (it had in the machine) Investigating further showed me that the 1 second / 250 millisecond / 125 microsecond bursts were actually formed in the MI12 - the OMM just passes them on as IR - (this fact becomes relevant later)

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 10, 2018, 05:37:21 PM
The ICL7660 is a switched capacitor circuit, it's commonly used to produce a negative rail for op amps. The output voltage should be a negative mirror of the input voltage, so measure pin 8 vs pin 5 (with pin 3 as your reference) the voltage on 5 should be the negative equivalent of pin 8.... If it's not then you have a cap or over current problem.

PK
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 10, 2018, 05:56:43 PM
Thanks for that PK.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 10, 2018, 10:08:28 PM
Yeah, that looks like the bulk cap for the input to the 7805, look for ripple on the little output ceramic in that picture.
Anything more than a few hundred mV is bad.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on September 11, 2018, 04:29:01 AM
Looks promising..if that capacitor is blown chances are it's something on the circuit that has gone out of spec and blown the capacitor rather than it failing all by its self.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 11, 2018, 09:34:51 AM
IMO, input caps for regulators tend to blow when they see voltage spikes, so I wouldn't be too concerned about root cause..... Just replace it and trust in Jesus......
PK
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 11, 2018, 10:09:31 AM
I've got an SMD capacitor on order, and I won't pull the OMM again until it's to hand. But if it is the input cap for the 5 volt regulators then I doubt that it's the fault, just 'a fault' as both 5 volts regs measured ok on the Fluke - this thing takes in 10 volts from the MI12 which is itself regulated (I'd assume) so as PK says - just change it !

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 13, 2018, 05:53:33 AM
The ordered SMD capacitor arrived by post this morning, so I braced myself for some VERY tiny soldering. But when I opened the envelope I thought - 'by heck those ARE small'

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 13, 2018, 08:30:38 AM
If the voltage rating is adequate, then just solder them in. 7805's aren't particular about input  caps.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 13, 2018, 08:58:51 AM
PK at that scale I don't fancy putting in wire extensions - it's about the limit of my soldering dexterity to get them off and on, never mind extra floating bits of wire  :lol:

(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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 14, 2018, 07:57:27 AM
In anticipation of the correct capacitor arriving, I made up an extension cable, in order that the OMM could be be driven by the MI12 on my desk for testing purposes.
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 SIGNAL

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 14, 2018, 09:01:53 AM
I made up a mounting jig to stop the PCB skidding all over the desk when testing !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 15, 2018, 03:36:24 PM
I came across this Youtube video where Tom has done quite a bit of investigation into the OMM. Not all relevant but some useful stuff there:


&t=2184s
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 16, 2018, 07:30:38 AM
OK so the problem is to try and work out which component or components is drawing too much current from the negative rail, and dragging it down from -5v to -3.5 volts.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on September 18, 2018, 08:07:27 PM
Are you able to inject -5v separately? If something is dragging the line down, that may make it more visible (eg hot), or show it is the converter itself at fault.



Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 19, 2018, 10:45:32 AM
Russ,

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on September 19, 2018, 01:36:15 PM
I have a hot air gun if you need to borrow it Andrew.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 19, 2018, 01:40:41 PM
That's very kind Pete, let me have a think about it - you can't lend me two good eyes and non trembling hands as well can you  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on September 19, 2018, 02:27:20 PM
SMD working isn't that bad, although I'm not sure I'd want to start with trying to fix something quite so expensive!

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 20, 2018, 06:15:26 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.

Very many thanks to PK who is definitely a 'good chap'  as I was going cross eyed chasing this problem :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.

Very many thanks to PK who is definitely a 'good chap'  as I was going cross eyed chasing this problem :thumbup:
Another example of "It's not what 'ya know, it's who 'ya know!"
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 20, 2018, 11:33:32 AM
Or rather:

 :mmr:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: kayzed1 on September 24, 2018, 04:09:10 PM
 Is it back yet dad? :) :) :lol:
Lyn.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 24, 2018, 04:21:22 PM
Still going round in circles as usual Lyn !

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 27, 2018, 02:34:57 PM
OK a tiny weenie bit of progress on spindle orientation. The format of the code is:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 28, 2018, 05:45:29 AM
And a bit more progress. The OMM PCB and probe have arrived with PK in Perth, Australia and he has it on the bench with power on and is looking at it. I just hope it doesn't make his head spin like it did mine !

Thanks PK  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 28, 2018, 06:50:51 AM
So the first thing you do when someone says: "Can you take a look at this for me, it's doing X,Y, and Z",  is fire it up and check that its actually behaving that way and there are no other obvious faults.



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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 :) :) :)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 28, 2018, 07:23:54 AM
Yikes PK  :bugeye:

. . . 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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on September 28, 2018, 08:19:06 AM
Yeah, it could well be the thing that amp is driving that is causing the problem, I'll test the amp and that transistor tomorrow. At least we have a starting point now...

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on September 29, 2018, 05:03:40 AM
PK, if it's like other Renishaw stuff I've opened up, it'll be O ring seals I suspect.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 02, 2018, 03:17:57 PM
In anticipation of PK working miracles with the Renishaw Probe electronics, I decided that it was time to plan a re-do of it's wiring. As I think I've previously mentioned, it seems to be a field upgrade with the necessary wiring just draped any old place that they could get it. The MI-12 interface unit is hard wired in, and just sitting on a shelf.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 02, 2018, 03:25:24 PM
So a quick pencil sketch, rapidly followed by an Autocad drawing whose DWG file was processed by SheetCAM to give me a CNC-Plasma ready file to cut.

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 04, 2018, 11:24:11 AM
Well a bit of progress today. A couple of weeks ago a CPU card for the Sinumerik 820T  controller popped up on eBay in the USA at an attractive price - usually people ask silly money for them - whether they sell or not is another matter!

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.


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 04, 2018, 12:28:52 PM
Before Parcelforce delivered the CPU card I had started an intensive review of why the 'cracked' version of STEP5 PLC software wasn't loading. Now I would not normally entertain 'cracked' software, but STEP5 has been updated to STEP7 by Siemens and they had given me an official copy to try, but sadly STEP7 cannot talk to this particular PLC, and oddly Siemens can't provide a copy of STEP5 so I felt 'sort of' justified. Even so, these things can be lethal to down load with all sorts of nasties embodied. So with full virus protection and a pair of rubber gloves on, I 'had at it'  :clap:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on October 04, 2018, 03:17:45 PM
Do you know if it uses a standard serial cable or null-modem type Andrew?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 04, 2018, 04:09:42 PM
I'm pretty sure the cable I already use to up and download the files to the 820T from my desktop will be fine Pete. It's a question of putting the controller in a state whereby the serial port is 'looked at' and 'talked to' by the STEP5 program. Early versions of programmers that talk to this controller used 'current loop' and ran under CP/M but I know that although the 820T is fully capable of being set up for current loop, later programmers used RS232 as per the up and down loading.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 04, 2018, 04:21:08 PM
For any one passing this way who is familiar with STEP5 software and can offer help, this is the version information:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 05, 2018, 06:34:25 AM
Progress comes in tiny little bits after expending hours faffing about  :lol:

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 . . . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 05, 2018, 06:45:01 AM
I know your google-fu is far better than mine... I presume you've done the obvious & googled for system message 0334?

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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 05, 2018, 06:52:46 AM
Thanks for that Ade  :thumbup:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 05, 2018, 06:55:12 AM
Hmm, ok, answering my own question.... looks like the product matrix indicates v7.23 is compatible with Windows XP SP1,2 & 3. So that shouldn't be a problem - although I might still be tempted to try a Win 95 system.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: DICKEYBIRD on October 05, 2018, 06:55:23 AM
Win98 is the last OS that will boot to "real" DOS if memory serves.  Ahh, the good ol' days! :beer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 05, 2018, 10:15:36 AM
If my memory serves me correctly, older Step5 versions tried to communicate to COM3 directly. If there were other programs, there were conflicts. But I never used any windows version and Step5.

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 06, 2018, 05:22:17 AM
I started this morning with three objectives:

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 ????
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 06, 2018, 06:43:01 AM
This:

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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 06, 2018, 06:56:20 AM
A thought occurs to me... as this is a "real" serial port, rather than some witchcraft thing, can you set the default values in the BIOS to match your requirements?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 06, 2018, 07:44:32 AM
Good thinking - I'll experiment after lunch  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 06, 2018, 08:47:05 AM
No luck Ade, all I can set in the BIOS is enable/disable for the port  :(

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on October 06, 2018, 10:18:55 AM
A quick Google seems to suggest that the defaults are 9600, no parity, 8 bits, 1 stop bit and xon/xoff. it suggests that you do not need to configure the handshake.

MODE COM2: 9600,n,8,2 should do the trick.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 06, 2018, 10:47:09 AM
Thanks, but if you look at the last picture you will see it actually defaults to 7 bit 1 stop and even parity  :(

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on October 06, 2018, 12:34:58 PM
I appreciate that, Andrew. I was just commenting that xon/xoff seemed to be the default. I know you've already tried it, but the suggestion is that Device Manager is the best was to configure ports post Win 95. Very strange   :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 07, 2018, 04:48:32 AM
You could try this syntax

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 07, 2018, 09:46:34 AM
Russ you are a genius  :bow:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 07, 2018, 05:57:46 PM
You could try sending some sort of response from your analyser to step5

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 08, 2018, 08:37:04 AM
Hi Russ, as I type I'm studying the 834 manual to see if I can implement your good idea  :thumbup:

(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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 08, 2018, 06:56:51 PM
Patience always helps!

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 09, 2018, 08:20:10 AM
The IDC-D-Type male and female connectors have been delivered, so I set to making up the three ways cable. Somewhere I have the proper squasher for making these cables, but for a one-off the vice with soft jaws was perfectly serviceable.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 09, 2018, 11:57:00 AM
We're On Line !!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 09, 2018, 12:46:57 PM
OH, happy day!

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 09, 2018, 12:55:50 PM
Oh EXCELLENT Pekka, I now appoint you the official resident expert - can I down load your brain please  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 09, 2018, 03:16:17 PM
Uuh...if I remember anything. I'm trying to learn how to weld. This should sort it out.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 09, 2018, 03:31:23 PM
I hope you're not using that Single Malt for weld preparation  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 09, 2018, 05:19:38 PM
No. That is old military stable, mostly industrial grade alcohol and some confiscated Cognac. Tastes like an alcohol. Not clean enough for cleaning and not tasty enough for consumption. Perfect for Finns. :lol:

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on October 10, 2018, 01:16:32 AM
We have this on the wall at work.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 11, 2018, 09:05:30 AM
I've been unable to work in the workshop all yesterday due to a plague of flies - literally thousands of  them, but I think I've now got them down to manageable numbers, with just the odd one or two pingng off fluorescent light tubes. I think something must have died on the roof.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 11, 2018, 09:20:29 AM
Is it downloading to a file or memory?

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 11, 2018, 11:01:40 AM
Theoretically to a file, but I'm having difficulty deciding if it actually has  :scratch:

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 11, 2018, 03:29:51 PM
Oh yes Pekka, unless I'm VERY lucky this is definitely gong to be a long haul now I have my teeth into it.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 12, 2018, 04:18:24 AM
Looks vaquelly familiar.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 12, 2018, 06:15:08 AM
Thanks for that Pekka, that's a useful document that I will add to my reading list !

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 13, 2018, 05:36:32 AM
I started the day intending to lower the baud rate on the STEP5 to 820T controller link, to try and resolve this locking up issue.

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 . . . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 13, 2018, 06:13:17 AM
So somehow the download is writing to disk in a way that the controller doesn't like..

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 13, 2018, 06:42:01 AM
Russ, STEP5 is very much in charge here !

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 13, 2018, 07:02:51 AM
Did you get your analyser running? I must I'd be surprised if you were getting flow controlled at that speed.

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 13, 2018, 07:52:43 AM
Yes I have the analyser able to run in 'monitor mode' - it's fairly old technology and gobbles up data into a buffer, and though you can see characters coming in, you have to stop the capture routine before you can have a good look at what you've captured.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 13, 2018, 08:00:44 AM
Been there... Actually yesterday, at work, looking for missing responses.

Throw in Bluetooth, packet encryption, Android and 4g network none of which take kindly to a request to explain what is going on.

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on October 13, 2018, 08:09:48 AM
Would it be worth investing in a Saleae compatible logic analyser, such as https://www.ebay.co.uk/itm/24MHz-8-Channel-USB-Logic-Analyzer-Saleae-8-CH-Logic-Analyzer-for-MCU-ARM-FPGA/112657150662 (plenty other sellers available)?

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/
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 13, 2018, 09:52:22 AM
Thanks for the link Moray, but I think it might complicate things even more than they are. I only have access to signals at the RS232 +/- 12 range so at the very least I'd need to build a simple level shifter for each CCIT circuit.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on October 13, 2018, 10:48:57 AM
I never realised this was running at full 12V signal levels.

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 14, 2018, 03:20:29 AM
Have you tried with one to max 1,5m long serial cable without any extras. I remember having same sort of problmes with long cables or faulty adapters. Laptops strugle with RS-232, their serial port buffer hardly never goes very negative, often it is even under -5v and any troule with cable is diaster. I never used flat cable, it was short shilded cable or I could not even get it to connect.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 14, 2018, 05:28:47 AM
Pekka I agree about flat cable - I'm only using it in a temporary adaptor set up for the analyser. (Though Siemens use about 1.5 meters of the stuff to link the X121 RS232 port on the CPU card to the socket on the operators panel.)

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 17, 2018, 07:31:09 AM
A bit of progress, but I've been delayed by moving a manure heap and reseeding more ground, to say nothing of still fighting the fly plague :bang:

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'
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 17, 2018, 01:30:11 PM
A tiny bit more progress, (or probably more confusion), I've been pointed to an '.INI' file buried deep in the file structure of STEP5, that holds settings for all the COM ports from 1 to 6.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 18, 2018, 04:00:13 AM
Did you also use mode to set what you need? Clearly some very odd interactions between all the bit players in this drama.

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 18, 2018, 04:14:45 AM
Russ,

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 18, 2018, 06:59:19 AM
Hopefully then the controller is not as stubborn in the parameter department as step 5...

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 18, 2018, 07:23:24 AM
The really frustrating part is that this same RS232 link is used for uploading and downloading programs to the controller and works fine.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 18, 2018, 10:19:24 AM
Farnell, good to their word, delivered the alternative MAX3232 PCB - the 'Sparkfun BOB-11189. So grabbing the soldering iron I quickly connected it up to a female 9 pin-D-Type and set the Logic SALE-AE analyser. Sure enough we can now go on line to the 820T and listen to BOTH sides of the conversation.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 19, 2018, 05:49:40 AM
This morning I set off with the good intention of getting STEP5 to start downloading block "FB11" and timing with a stop watch when it failed (this is the block that previously had consistently given "Last Segment Not Completed") My intention being to monitor with the Logic Analyser and look at the interactions at about the time of the failure.

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.


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on October 19, 2018, 09:29:35 AM
You may have changed the loading on the rs232, which could be helping some sort of voltage/reflection issue...

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 19, 2018, 09:44:06 AM
To illustrate this conundrum I'll post some screen shots of some of the blocks in the PLC as downloaded by STEP5

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on October 19, 2018, 11:03:51 AM
PB202 looks very suspect, given it should be far longer compared with the rest.

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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 19, 2018, 11:30:00 AM
Yes it's very odd Moray, and try as I may I can't at the moment see any way of getting further segments.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 20, 2018, 02:18:14 AM
Can you open the files out of step5 - notepad++ maybe - and compare the contents, at least for size?


Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 20, 2018, 04:05:09 AM
Russ that's a good suggestion but one I've failed to accomplish  :palm:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 20, 2018, 04:46:05 PM
Well progress   :thumbup:


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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on October 20, 2018, 07:16:42 PM
That is good news!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 20, 2018, 10:41:56 PM
I hate intuitive interfaces....

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 20, 2018, 10:42:28 PM
Or, 'intuitive' interfaces to be precise



Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 21, 2018, 04:55:21 AM
It turns out that the one 'Program Block' PB202 has 172 segments full of all sorts of complexities waiting to be de-coded. (But all the other blocks are 'single segment')

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 21, 2018, 10:50:51 AM
Well I've discovered a STEP5 utility that takes a file generated in STEP5 and allows it to print on the default windows printer - so that's one more hurdle straddled  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 21, 2018, 01:05:31 PM
A VERY nice man on the Siemens forum has offered to take my STEP5 project file and turn it into a PDF of the ladder logic, so I've just zipped it up and posted it on the forum.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 21, 2018, 03:57:09 PM
Is this "ladder logic" what you and I would more generally know as the G-codes which form the program? Or is this something else? Am I likely to have to learn all this stuff for my Mazak, if I ever get it going?  :bugeye:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 21, 2018, 04:25:08 PM
Ade,

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:


 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on October 21, 2018, 05:38:06 PM
I've said it before but I have to admire your tenacity Andrew.

That wouldn't be giving me any more trouble by now if I was working on it  :hammer: :hammer: :hammer: :hammer:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 22, 2018, 02:29:57 AM
Aaah, I see! Very clever  :smart: 

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).
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: David Jupp on October 22, 2018, 03:38:22 AM
But the one in Andrew's screen shot looks like an SR not an RS so Set will take priority over Re-set as this rung is evaluated.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 03:49:11 AM
Ade, I need the whole shooting match to check what is happening with the M20 command.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on October 22, 2018, 04:16:41 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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 04:23:44 AM
So it's only taken since the beginning of August to get STEP5 running, talking to the 820T controller, and getting a vague understanding of my way about inside the PLC program. Not quite three months so it could have been worse !

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on October 22, 2018, 05:45:48 AM
Have you not got it all traced yet?
It's only 33 pages, and the first doesn't even contain any segments...  :D
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 06:58:17 AM
Thanks for the encouragement Mory  :clap:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on October 22, 2018, 09:02:51 AM
That does not look too bad...Only it is ladder and I am more used to FUP. Some statement lists the but I did not spot any assembler.

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 09:24:55 AM
Thanks Pekka, not come across FUB but I do know LOTS about FUD or Fear Uncertainty and Doubt  :clap:

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: )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 09:54:13 AM
So continuing on the theme of self education, and boring the pants off you, segment 1 translates as follows:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on October 22, 2018, 04:22:11 PM
Not that boring but does make one scratch their head!
Iím waiting for the lightbulbs to turn on!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 04:40:01 PM
You and me both Tom  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 22, 2018, 06:10:07 PM
Thanks for the link Ade, no I don't have that particular manual. It's for the S5-135U  Stand Alone PLC that the PLC embedded in the 820T controller emulates.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PK on October 24, 2018, 04:21:17 AM
So I've spent a little time studiously ignoring Andrews 'How's it going' messages whilst staring at that probe trying to figure out how to get into it.... It resisted hand opening, and there seemed no way to grip it with tools without digging into the anodised finish. I'm certain that special wrench #27 exists and does the job perfectly. But I aint got one! I don't even have a 25mm collet to grip the shank..... So it sat on the healing bench for a few days whilst we stared at it..  In the end some disassembly allowed me to bolt on a strip of metal that I could get a spanner onto, and a bit of scrap bored to 25, slit, and held in a vice did the job.
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....
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RotarySMP on October 24, 2018, 07:22:18 AM
Hello Andrew,

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 24, 2018, 07:28:44 AM
PK good progress, thank you  :thumbup:

But I'm a little confused - are you saying that the OMM is now responding both ways, or the probe module ?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 24, 2018, 07:32:41 AM
Mark,

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RotarySMP on October 24, 2018, 08:07:00 AM
Thanks Andrew, since you have done a lot of this work, have there been cases where you went the other way and retrofitted?
Mark
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 24, 2018, 08:44:02 AM
VERY many years ago I did a Denford ORAC lathe and a Denford TRIAC mill. I bought both with totally destroyed controllers and fitted PC's running TurboCNC, as Mach hadn't got off the ground in those days. They worked very well and had the advantage that I knew the control programs inside out as I wrote them. Too small though so they financed the purchase of a Bridgeport Interact.

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 24, 2018, 11:45:05 AM
Just to show you that I've not been entirely idle I'm attaching the main PLC program block 'PB202' with the Inputs, Outputs, Flags, Timers etc that I have so far managed to identify labelled.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 26, 2018, 05:35:41 AM
No activity yesterday other than printing out my latest cross reference list, as a reunion with friends in Littlehampton was the order of the day - early departure and late return.

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on October 26, 2018, 06:25:43 AM
You must be chuffed Andrew...
 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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 28, 2018, 03:04:28 PM
Using the (new to me) PLC ladder testing approach is both swift in some ways, and mighty frustrating in others. Although I reckon that I have the majority of the logic 'nodes' (ie inputs outputs and flags) named so that I can find my way around, inevitably I end up in a bit of logic where I've not yet been able to plant signposts  :scratch: I reckon I've still 102 out of 490 nodes to name and identify the purpose of

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on October 28, 2018, 05:05:06 PM
Ugh.  I hate pressure switches!  Just a time bomb ticking off till failure.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on October 31, 2018, 08:21:31 AM
Taken a bit of time off to sort out some tooling cabinets for the Beaver TC-20 lathe - Versatool ones like I used for the Traub - details here:

https://madmodder.net/index.php/topic,8741.msg152687.html#msg152687

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 01, 2018, 08:09:31 AM
Major break through today in the hunt for the M19  Oriented Spindle Stop problem that has been eluding me for ages.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on November 01, 2018, 11:28:08 AM
The gain would be the obvious choice to prevent hunting. I can just about recall this was fairly critical when I was playing with feedback on RF frequency synthesizers.

Perhaps the drift compensation is damping. (Then again, perhaps it isn't)

Well done!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on November 01, 2018, 03:54:22 PM
Ooooh!  Tool (cabinet) lust!  Love the swing out shelves!  My Hardinge does that for collets.  I _might_ have made my own custom "board" out of Aluminum...

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 02, 2018, 12:16:33 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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 02, 2018, 04:02:37 AM
Thanks chaps for the suggestions.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 02, 2018, 07:59:42 AM
Monitoring the analogue drive to the Mentor DC Spindle Drive when being driven by the controller it seems believable, about 3.5 volts at 1000 rpm and 9.99 at 3500. 3500 is maximum speed so sensible that that is 10 volts ie full range. I've not tried yet driving it from my little servo battery box  as a last minute booking for the holidays cottages threw us into a bit of a panic  :bugeye: I have however managed to find the little box and check that it's batteries are still alive.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on November 02, 2018, 09:45:11 AM
Line #19 "Set resiprocation speed"? Is it explained aqnywhere? Is it overshooting speed? What will happen if you set same than approach speed? I would test that 40/50/60 values (If set speed is 50) and see if overshoot characteristics change. I guess if you set it zero, it goes only one way and either stops inside the error or overshoots and stays there.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 02, 2018, 11:55:18 AM
Pekka, the reciprocation speed is used for lathes like this one with gear boxes, to let the gears 'rock in' as you change gear.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 02, 2018, 12:24:02 PM
So Andrew does the spindle have a brake to keep it from moving when milling and drilling etc ..and could you mill a large square thread for example by rotating the spindle and feeding the turret in the z axis..?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 02, 2018, 12:57:22 PM
The M20 'preparatory function' for the M19 takes the brake off if it was on, and asserts 'Spindle Enable' and 'Servo Enable' . Once the M19 function gets to target it applies the brake, and removes 'Servo Enable'

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 02, 2018, 02:38:50 PM
Yes when you think of the possibilities especially with the tail stock for holding long parts  :jaw: 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 04, 2018, 05:06:01 AM
I have wired my Fluke DVM to the analogue drive signal from the 'measuring circuit' to the Mentor DC drive, and sure enough as the gain is increased the magnitude of the position error signal increases and the 'dead band' decreases, but if the gain is set high enough for the spindle to be positioned crisply then the system oscillates. Backing off the gain so that the oscillations  cease but we are not at set point, I can manually rotate the chuck through set point and if going slowly enough the system will 'lock on'

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 04, 2018, 05:17:38 AM
Now looking at the manual for the 810T (mine is an 820T but running the same GA2 program) there are flow charts for how the servo system is controlled and how M19 is implemented, but none of it so far has triggered that 'lightbulb moment' for me to say what's wrong here!

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on November 04, 2018, 06:37:15 AM
It's like either the PLC is needing to apply a bit damping to the output, or the Mentor drive is applying too much damping/not responding quick enough.

If the PLC settings seem plausible and you're sure they're valid, what about the settings in the Mentor drive?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 04, 2018, 06:55:19 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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 04, 2018, 07:03:20 AM
Morry, the Mentor 'ramp' settings for accelerate and decelerate seem to be the only ones relevant. Yesterday I had gone from a setting of 20 to a setting of 50 (not sure of the units) with no effect. Now this morning I took the ramp settings up to their maximum value of 255 but again with no apparent change. (I was surprised not to to see a difference when just starting and stopping the spindle with an M03 / M05 though)

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on November 04, 2018, 07:38:25 AM
I would of thought the Mentor would have more than ramp settings.
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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 04, 2018, 09:42:39 AM
Well a bit more aggressive Googling has found me the correct 'Mentor 1' manual - a 'good thing'  - All 24 m Bytes of it.   :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on November 04, 2018, 09:56:45 AM
I bet it's 999.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on November 05, 2018, 05:30:47 AM
Or 000, 111,222,333 etc.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 05, 2018, 05:59:59 AM
Well it's even simpler than Pete's 999 . . .

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 05, 2018, 02:40:42 PM
So a bit of intensive parameter investigation today - I put together a document with the best description of each (apparently) involved parameter concerning the Spindle Orientation and M19 that I could find in the various description that I have. 

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on November 05, 2018, 06:21:34 PM
Sounds like there's a deadband set in the Mentor.

I'm assuming you can view the AD value on the Mentor some how going by that bit text?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 06, 2018, 11:28:58 AM
I awoke to the realisation that although I thought that I'd eliminated the Measuring Card by substitution, that was BEFORE I'd cured the M20 fault, so M19 wouldn't have worked anyway  :bang:

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on November 06, 2018, 11:44:33 PM
Those bangs are clamping and releasing?

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 07, 2018, 02:37:06 AM
Yes that is the spindle brake being energized and released. As soon as the servo system has locked onto set point it puts the brake on and it is released by the next M20 command or a specific M32 unlock command.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 07, 2018, 07:20:34 AM
Once again I'm impressed by your persistence.  :bow:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 07, 2018, 10:36:48 AM
Russell,

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 07, 2018, 11:34:55 AM
An interesting (but possibly irrelevant) bit of maths entered my head this afternoon:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on November 07, 2018, 01:35:48 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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 07, 2018, 01:54:24 PM
Hi Andrew

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


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 07, 2018, 06:06:09 PM
The delay 'tv' is timer T1 in segment 69 of the program, which is triggered by 'on target' and is the 300 mSec period during which  'on target' has to be asserted.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 08, 2018, 05:01:34 PM
Hi Andrew
 
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 08, 2018, 05:08:43 PM
Russell, yes I agree. The parameters that I managed to get from the lathe user had the approach speed (cut off speed) at 5 rpm but as I'm sure that you are aware from reading my posts I cannot get it turning reliably lower than 8 or 10 rpm.

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 09, 2018, 05:58:54 AM
Hi Andrew

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 09, 2018, 07:34:50 AM
Russell it is feasible to measure the voltage, but it means temporarily removing the cooling fan that I fitted to save the thyristor cooking. I may well add some remote terminals to make the job easier and safer as it's easy to get a nasty shock when probing (ask me how I know!)

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 09, 2018, 12:28:47 PM
Well I modified the fan mounting plate to allow me to get at the field coil connections while tweaking the field current pot. Taking it all the way up to maximum only got me 165 volts, plate rating is 170. I shudder to think what the current was.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 09, 2018, 05:57:03 PM
That's interesting, but not especially helpful - except that all information helps.  I'm sorry if I diverted you up a blind alley.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 10, 2018, 04:39:05 AM
I might have missed it in the thread but have you checked the belt tension motor to spindle..presuming it's a toothed belt..might be some back lash there when you change direction or maybe the belt needs replacing if it's been stood a long time?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 10, 2018, 06:23:43 AM
Good thought but there is no sign of belt slippage or squeals. It's a very wide multi-groove affair.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 13, 2018, 05:20:18 AM
Well the usual running round in circles and chasing my tail has produced results.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 13, 2018, 05:34:29 AM
So I decided to read the Mentor-1 DC spindle drive manual from end to end leaving no commas and full stops unmolested  :bugeye:

. . . 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


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on November 13, 2018, 05:42:14 AM
I knew you'd find it! :nrocks: :nrocks: :nrocks:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 13, 2018, 07:58:38 AM
And now the new parameters are saved  :ddb:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on November 13, 2018, 09:59:32 AM
Well done that man  :headbang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on November 13, 2018, 11:40:08 AM
RTFM failure :D

Well done Andrew!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on November 13, 2018, 01:35:45 PM
Very good job!

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 13, 2018, 02:38:26 PM
Thanks Pekka,

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 14, 2018, 05:40:18 AM
Perhaps the machine was supplied without the c axis option..ie. the parameter turned off in the Mentor . If the customer requested the c axis it would be an easy fix.. Beaver charges £££ to simply alter a parameter..I know I'm being cynical but this type of thing does happen especially on the Japanese machine tools!!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 14, 2018, 08:50:31 AM
Ya-but. . . . .

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 15, 2018, 07:30:20 AM
Well today is ANOTHER official GOOD DAY   :ddb: :ddb:

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on November 15, 2018, 08:16:10 AM
Now that is what I call excellent after sales service. Nice to see that they still take the time and effort to support their products after such a long time.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 16, 2018, 05:57:02 AM
Just out of interest Andrew..is it possible to upgrade the C axis to full 4th axis or does that require replacing major components like the Mentor drive..?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 16, 2018, 07:02:24 AM
Well the spindle encoder is there (1024 lines) and the DC Drive would do it, but the firmware embodied in the controller isn't set up for it as far as I can tell.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 16, 2018, 08:41:17 AM
I see makes sense..maybe it was an option back in the day.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 17, 2018, 06:48:43 AM
Having got the Spindle Orientation now sorted the next barrier to knock down is getting the powered tooling working, after all that is why I need the Spindle Orientation in the first place.

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 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 17, 2018, 11:59:01 AM
So embryo replacement drive dog drawn up in Fusion 360 and now printing on the Cetus 3D printer. This is just to let me better visualise what I need before I start machining - be nice if a 3D printed part could just be used as is !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 17, 2018, 03:05:03 PM
So the 3D Printing has finished, and I've been able to use the model to measure how long it needs to be to engage, and yet have clearance when the tool disk rotates.

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.




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 17, 2018, 04:18:00 PM
I'm tempted to make a 'D-Bit' to a 12.5 degree taper. The real problem is that the 'root' of the gash at the inner (narrow) end is only 2 mm wide, so any cutter will be fairly delicate.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on November 17, 2018, 05:33:24 PM
Can't you cast one in bronze or brass from a 3d print and do the fettle to final fit on manual machines and hand tools?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on November 17, 2018, 06:55:58 PM
Can you post a picture of the mating end?  I really wonder how it was made!
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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: chipenter on November 18, 2018, 01:42:36 AM
Tilt the rotab over 12.5 degrees and use a slitting saw  .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on November 18, 2018, 01:58:22 AM
Surely you could wire EDM the sides but I don't see how you could do the bottom.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 18, 2018, 05:30:59 AM
I wonder if Baruffaldi has a part you could modify with the teeth already machined..it's a curvic coupling..these are hardened and ground to micron tolerance usually..larger ones are used on 4th axis horizontal machine centers to locate the pallets. Any slop would cause wear over time hence the need for a precision fit?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 18, 2018, 06:00:10 AM
I'm sure that the original Baruffaldi drive dog was steel, and machined. But of course I have never seen one, as my lathe was fitted with the dog to fit 'hens teeth rare' Beaver powered tools. So my 3D model is entirely guesswork but must be close. The dog shaft actually slides and is spring loaded into contact.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mattinker on November 18, 2018, 06:07:22 AM
Andrew,

how about a three D printed core and cast in bronze using  a fine petrobond sand mold?

Regards, Matthew
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mattinker on November 18, 2018, 08:34:17 AM
Me again! You could print on your 3D printer two or three piece mold to cast a wax version of your part?

A passing thought, cheers, Matthew
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on November 18, 2018, 09:21:55 AM
Worth a try with plastic..if it breaks you can upgrade to steel..nothing lost..wondering though if a heavy cut in steel might sheer the teeth of a plastic version  :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on November 18, 2018, 09:30:51 AM
Our demo machines have splined plastic couplings from the 22kw motor to the hydraulic box. Worth a try IMO epsecially if you can beef up the sides and put healthy fillets on the diameter transitions.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: DICKEYBIRD on November 18, 2018, 11:54:11 AM
Seems pretty simple Andrew; just invent a carbon filament for your printer, whip out a reverse image of the coupler face  in CAD & print yourself an electrode for your EDM.  Easy-peasey!  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 18, 2018, 12:02:17 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 plaster has a short shelf life and only comes in big bags !

https://homeworkshop.org.uk/
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on November 18, 2018, 02:09:15 PM
I've seen a video of someone doing bearing blocks for a CNC router by lost PLA casting and get tolerances good enough to use without further machining.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: philf on November 18, 2018, 02:18:58 PM
Is there enough meat in the teeth to drill holes for steel dowels for reinforcement? (And perhaps a steel sleeve over the OD below the teeth.)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on November 18, 2018, 02:22:20 PM
On mulling over this a bit further, is there any reason why printing this with ABS and treating it like a wax model for casting in bronze but using an excess of acetone to dissolve away the core instead of heat wouldn't work?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on November 18, 2018, 02:41:45 PM
Or try this
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 18, 2018, 03:16:28 PM
I've been put in touch with a couple of firms who may be able to to make a bronze cast from the STL model via the Home Workshop advert.

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 19, 2018, 10:20:51 AM
Been trying to resolve the 'Turret Unclamped' switch issue where it seems very slow to operate when cold taking up to 10 seconds for the contact to close when the Turret it pushed forwards for a tool change by the hydraulics.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 20, 2018, 06:12:17 AM
I set off this morning with the intention of doing a bit of tool setting, then writing a diddy program to incorporate the Spindle Positioning and milling using the powered tooling.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 21, 2018, 07:15:27 AM
A few developments today:

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.


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 22, 2018, 08:23:41 AM
I decided that it was time to pull the new cables through for the Renishaw OMM probe that PK is  kindly working on for me.

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 !)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 22, 2018, 08:26:47 AM
...cont:


Now I just need to remember how all this tin work goes together  :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 22, 2018, 03:46:36 PM
After lunch I made off the cable ends on the back of the socket box and mounted it thinking I'd have to leave it at that until I got some flexible conduit for the far end of the signal cable.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 23, 2018, 10:09:11 AM
So having got the new cables in the ducting I could make a start on replacing the various panels that I had had to remove to get at it. You may recall that they were a pain to remove entailing making a 1 metre long allen key, and they kept up their reputation going back. Two on the external tail stock end of the machine, and two swarf / coolant guards inside.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 24, 2018, 07:16:46 AM
Time to sort out the mounting of the last end panel. Various threaded inserts in both the panel itself and the adjacent panels, but no access to fix or tighten screws.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 25, 2018, 09:28:05 AM
So why the rush to get the panels back? Well apart from the fact that they are taking up needed space in the workshop, I wanted to bring in one of my newly acquired Versatool cabinets and start tidying the lathe tooling away. Up till now it's been on the floor / work surfaces / anything vaguely horizontal and I'm running out of elbow room.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 27, 2018, 05:33:42 AM
At long last the screws in the 90 degree powered tooling head have surrendered and now all are out  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 28, 2018, 06:52:20 AM
So this morning I found a bit of time to start pulling the 90 degree VDI40 powered tooling holder apart. Everything was rather tight with two dowels refusing to let go for a long time. It wasn't until I was nearly there that I discovered that they were drilled and tapped M4 for a slide hammer to extract them which would have been so much easier !

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 28, 2018, 08:25:19 AM
. . . .then it dawned on me . . I could 'take the waiting out of wanting'  (who remembers where that quote comes from ?) by using my 60 ton hydraulic press.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 28, 2018, 12:31:19 PM
So having ordered up the Needle Roller Bearing and three seals, and 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) rather than twiddle my thumbs I decided to sort once and for all the interference between the mounting face of this device and the central swarf guard on the turret itself.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 28, 2018, 03:02:39 PM
odd that, they were my first port of call  :scratch:


... correction - no it was Bearing Boys I went first  :bang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 28, 2018, 05:10:57 PM
O ring ordered  :thumbup:

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on November 28, 2018, 05:41:07 PM
What's next? Turn a pinch collar to grip the OD with a m4 thread in the end for pulling on?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 29, 2018, 03:59:12 AM
A good idea Pete but not necessary as THE DOWEL IS OUT  :ddb:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 29, 2018, 05:41:28 AM
The next job was to make some replacement dowels - simple enough as I happened to have some 6 mm precision shafting. From a dismembered printer I suspect.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on November 30, 2018, 06:24:45 AM
The bearing and seals arrived in today's post so I could get on re-assembling it while the pottery kiln cooks a bit and dries out (hopefully).

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.



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 01, 2018, 08:28:50 AM
Big O ring still not arrived so I decided to modify the drawing for the spanner that I made for the axial powered tooling to incorporate an opening at the 'other' end to fit the locking flats on the 90 degree holder.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 03, 2018, 03:02:51 PM
At long last the rather odd sized O ring arrived - (well actually a bag of ten of them !). I strongly suspect that the original would have been fine, but whilst things are apart it's best to do a proper job I reckon.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 04, 2018, 07:22:08 AM
This morning I re-installed the tin work on the turret. Went reasonably well considering the contortions needed for screw access  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 04, 2018, 08:48:54 AM
Fortunately, by elongating the 6 mm mounting holes slightly, and biasing the cover towards the tail stock  as I tightened the screws, I was able to get just sufficient clearance for the pulley hub not to rub. It is mighty close though.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: vintageandclassicrepairs on December 04, 2018, 06:58:07 PM
Hi Andrew,
What about cutting out the damaged section and welding in a new piece?

John
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 05, 2018, 02:28:49 AM
Yes I gave that approach serious consideration before I started trying to flatten the damaged bit, but frankly the whole thing is distorted. I assume that it came into contact with the tail stock sometime in its history.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 05, 2018, 07:13:46 AM
The plan today was to measure and draw up a model of the cover, print it on paper, glue it on card, and try it. That plan fell by the wayside as I tried juggling multiple A4 print outs.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 05, 2018, 10:09:59 AM
I did actually make a third one incorporating the missing bit and then started on the second section. Just a strip folded with some interestingly close together folds that involved modifications to the folder.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 06, 2018, 11:10:52 AM
Time to glue it all together. I dug out my Migtronic KDX 250 MIG welder that is loaded with 0.6 wire but try as I might I could not get it set up. The 'burn back' circuitry and control don't seem to be working - something to fix when a RoundTuit  comes along ! So I had to resort to the Butters AMT  3205 which is loaded with 1 mm wire and better suited to welding 6 mm plate.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on December 06, 2018, 02:22:05 PM
Nice job!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 07, 2018, 08:18:01 AM
So last night the cover got a bit more tidying up and rubbing down, then this morning a rattle can coat of zinc rich primer on both sides while poor old Hugo the Vizsla  succumbed to the sedatives he had to have prior to a vet visit (swollen toe not responding to treatment).

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 08, 2018, 03:28:54 AM
Having the newly re-commissioned  kiln to hand I decided to accelerate the drying of the first coat  by cooking it for an hour at 90 deg C. To avoid radiant heat damage direct from the element I used the 'simmerstat' control on the kiln to set a very low rate of heating - this switches the elements on and off with a period of a second or so, and hopefully avoids them actually glowing at this low setting. Can't be sure as the door is interlocked with the power.

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.


Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on December 08, 2018, 06:19:04 AM
Fly damaged paintwork is one of those things that is really annoying at the time, but a few days later, you have forgotten it ever was a problem! look at it from the flys point of view.................Seriously, I find I have to curb my desire for perfection because it can drive you (me!) to many hours of work that is completely unrecognised by anyone, including yourself, even a few hours later. More to the point, what is this metal loaded filler you mention, I have a little job that might benefit from some of that.This is still one of the most entertaining and intelligent threads on the forum, and I must admit a modicum of addiction which I am trying to curb by not making Mad Modder the first forum I check every night after work. I am having some succes with this.Good luck with it Andrew, and keep it coming!
Phil
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 08, 2018, 09:34:57 AM
Phil, Thanks for the kind words. The filler is  Isopon 'METALIK' , but be aware - my tin is running out, so twice I've tried to buy a replacement on eBay (from two different sellers) and each time I was sent another Isopon product intended for repairing cosmetic damage to aluminium rims 'Isopon Alloy Wheel Filler', and when I contacted them they both said that their bulk box was wrongly labelled (and keep the tin). It may be as good for all I know but it's not the same !

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on December 08, 2018, 06:28:11 PM
Looks dam good!
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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 05:19:07 AM
Thanks Tom :thumbup:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on December 10, 2018, 01:30:51 PM
Itís never boring watching posts there is always something that gets stored in the back of the brain!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on December 10, 2018, 01:39:19 PM
Bore us to death? I am waiting for the youtube channel! Today I have been mainly welding!
Phil.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 02:11:13 PM
So how to machine these little lost wax castings ?

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 02:23:45 PM
So far so good!

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 02:27:56 PM
A little bit of cleaning up and de-burring the edges, and it could be reversed in the chuck (far safer this way round!) for the seating of the fixing washer to be cleaned up
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 02:35:39 PM
So now the keyway needs broaching. This is a standard 4 mm broached keyway - I have a 4 mm broach but no 14 mm bush suitable, my bush was too wide. Never mind - shim it! After all broaches are shimmed to get the right depth, why not the bush  :clap:

The keyway as cast was a tad over 3 mm so not much to remove - two passes did it, second with a packing shim.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 02:38:01 PM
So that wasn't too bad was it - one down and one to go. :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on December 10, 2018, 03:21:33 PM
Those castings turned out very nicely indeed. Whoever did them has done a great job.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 10, 2018, 03:44:04 PM
Gary Allen did the superb lost wax castings - a very helpful chap  :thumbup:

http://www.geallencastings.co.uk/
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 11, 2018, 04:58:02 AM
Then it was a case of 'rinse and repeat'. Second drive dog machined up and broached. Quicker this time as all the decisions had been taken!

Again the bore only just cleaned up.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on December 12, 2018, 07:58:47 AM
 Looks great.

Awfully little material over the key way. Is that fusible or just no more space?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 12, 2018, 10:41:05 AM
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 12, 2018, 04:50:08 PM
Were I doing it again I would beef up the shank, leaving more meat  by the keyway, but also make the PLA model's bore far smaller leaving more the bore out on the lathe. Both bronzes only just cleaned up, at 14.05 mm, leaving slight 'witness marks' in place - perfectly serviceable but not ideal.

. . . 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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on December 12, 2018, 05:08:54 PM
Is the crown end going to be cleaned up or will it wear into place?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 12, 2018, 05:22:42 PM
The plan is to let it wear itself in. It has room to settle in a bit, but really it's just a case of watching and waiting as it is used.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 14, 2018, 05:48:09 AM
After weeks of wandering around various carriers and transport hubs, both in the US and UK, and having paid the  HM C&E ransom demand to release it, my Euchner Precision Switch has finally made it all the way from San Antonio in Texas. It's amazing how many places it's been on it's journey  :scratch:

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:




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 14, 2018, 10:31:23 AM
I've been keeping an eye out for a suitably robust and good quality rotating centre for this lathe. It needs to be 4 MT and preferably be dismantlable for servicing, unlike most of the import versions that are about.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 14, 2018, 10:39:09 AM
So how to test it?

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on December 14, 2018, 11:04:42 AM
Do the bearings sit in an oil bath and is that oil also used to indicate on the gauge?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 14, 2018, 11:53:16 AM
I'm honestly not sure - it's quite likely I expect.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 15, 2018, 07:09:22 AM
This morning I made the pin spanner to enable me to unscrew the front seal and bearing retainer from the  Rohm centre.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on December 16, 2018, 11:09:14 AM
I'm amazed your date has any stamp left after that!  ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 16, 2018, 11:58:28 AM
Yes I got carried away  :clap:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 17, 2018, 09:38:44 AM
I decided that the Rohm rotating centre was too vulnerable rolling about on the bench. I don't want it in place in the tail stock except when in use, as it's a nice spiky  thing to catch yourself on, when setting up tools. I had intended just to pop it in a suitable hole in one of the Versatol Cabinet shelves, but due to it's length I'd have to lower a shelf and waste a lot of space.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on December 17, 2018, 09:53:08 AM
If you'd pilot drilled they wouldn't have split, Andrew.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 17, 2018, 02:08:10 PM
I'm not convinced, it's only softwood.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on December 17, 2018, 02:56:32 PM
Soft wood you'd have had no problems.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 17, 2018, 03:23:08 PM
The next issue is what coolant to use. For years I've used 'Castrol Hysol Excel', which is a soluble oil product that I've used satisfactorily in all my machines and all metals.

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 )
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on December 17, 2018, 03:38:36 PM
'renamed' this product 'Castrol Alusol A'

A good job it wasn't renamed Anusol A  :D
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 17, 2018, 03:45:36 PM
Trust you  :clap:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 18, 2018, 07:36:35 AM
This morning I ventured into the wet bits of the coolant system - things could get messy  :bugeye:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 18, 2018, 07:56:17 AM
Then, not being able to procrastinate any further I made up half a bucket  of Castrol Hysol Excel from my remaining stock. Then I put a new input hose on the pump, balanced the end of the input hose well clear of the coolant, and with the original output hose cut short then dunked under the milky liquid, I went to the front of the machine to turn on the pump motor.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 18, 2018, 10:13:07 AM
It turns out that the latest version of Castrol Hysol Excel is now 'Alusol RAL BF' - where DO they get these names from ! It actually looks quite useful and I'm awaiting a quote - it seems a simple phone call isn't good enough these days to find a price.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 18, 2018, 11:26:03 AM
It turns out looking at the Patent Application drawing, that the Coolant Nozzle is supposed to be spring loaded, so as to seal properly as the tool disk re-locates backwards on a tool change. It wasn't, it was stuck tight !

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 19, 2018, 10:39:25 AM
There's no point in getting the coolant up to the tool disk without sorting out how it is directed at the individual tools. The VDI40 tool holder incorporates an internal duct from the hole in the tool disk to the outside world close to the tool, but there needs to be a short (about 2") length of tube of some sort directing it at the tool 'action point'.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 20, 2018, 06:09:00 AM
Slight change of plan: I decided not to use Loc-Line (despite having ordered it!) and to run the powered tooling coolant in brass compression fittings and copper tube. The Loc-Line doesn't go round as tight a bend as 6 mm copper will, and having a coil of 6 mm copper tube I can easily customise the nozzle length and shape in the future if different tools are loaded.

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 !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 20, 2018, 07:19:38 AM
For the threaded spheres I thought I'd see what I could bodge together from an M6 bolt and a bit of copper pipe. The largest hole I felt I could drill through the bolt was 3.5 mm and still maintain some strength in it, so I mounted it up in the lathe by the simple expedient of running a spare nut onto the end to keep it concentric. Then I ran  the drill through and counter bored with a 6 mm flat bottomed end mill.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 20, 2018, 09:45:44 AM
Made some more up this afternoon, so now all the tools that are fitted have coolant nozzles. The two locations in the tool disk that have no tools will probably have axial drills or boring bars so will need custom lengths as and when.


(Looking at the picture I must remember to put the missing VDI40 blanking plug in!)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 20, 2018, 11:58:55 AM
I found a curious thing later this afternoon . .

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 20, 2018, 02:03:09 PM
Mystery solved  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on December 20, 2018, 02:17:37 PM
Thatís the last place anyone would look! :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 21, 2018, 04:37:04 AM
A quick bit of re-labelling this morning has resulted in far more legible buttons than previously.

Of that row of 23 buttons only 7 are used. (as far as I know !!!)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 21, 2018, 05:09:54 AM
While I was clearing up the paper cuttings from labelling, the postman brought the replacement 'In-Tank' input filter.

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' !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 21, 2018, 08:30:29 AM
Well that was easier than I had expected  :thumbup:

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!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 24, 2018, 03:48:50 PM
I spent the afternoon scanning the User / Operations manual for the Beaver TC-20. I have an original paper back copy that is getting rather fragile. Siemens don't have it as a .PDF - it's apparently lost in time (!) so I thought it'd be a good idea to do it before my copy completely disintegrates.

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)

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on December 24, 2018, 04:13:56 PM
I use PDFill for splitting and joining PDF's. It's free and simple to use. Also installs a virtual printer so you can print anything to PDF output. I use that a lot.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 24, 2018, 04:20:22 PM
You know Pete I think that's what I used all those years ago - I seem to remember stumping up $20 to get the 'pro' version. I must search my email archive and see if I still have the enable code !



Later edit:

Yes, still have the code AND it still works - thanks for reminding me  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 28, 2018, 10:01:57 AM
Over the last couple of days I've snatched the odd hour here and there to finish scanning the  Operating and Programming manual, cleaned up the scans to remove various marks and blemishes, and made the major chapter index entries into active links within the document. It just remains to load it up to my ancient iPad which at the moment is resisting to co-operate. There are about 1500 photos from 2013/4 on it that I want to delete to free up some space, but the delete feature has vanished  :bang: When I tell it to look for updates to it's operating system it says 'searching' for ever, but can update apps quite happily  :scratch:

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 . . .
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on December 29, 2018, 03:54:21 PM
I have a sense of impending doom... Another awemawson project is coming to a conclusion.
I hope you are scouring the 'good home wanted' ads for the next exciting saga.

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 29, 2018, 04:31:02 PM
Funny you should say that Russ but the same thought passed through my head this afternoon as I was fitting the neoprene foam strips on the rear faces of the electrical enclosures before the panels go back.

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)

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Muzzerboy on December 29, 2018, 05:08:44 PM
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on December 29, 2018, 11:05:12 PM
My tig has also developed a fault. Pilot arc but no welding current.
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on December 30, 2018, 07:29:57 AM
So... are you keeping this lathe? Or selling it on ready for the next pig-in-a-poke you see on eBay?  :lol:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on December 30, 2018, 07:53:10 AM
Ade
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 donít need two CNC lathes I think
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 02, 2019, 07:22:15 AM
Today I was supposed to be fitting a "Tramp Oil" skimmer to the TC20 coolant tank. Tramp oil is the stuff that floats on top of soluble oil, and is derived from the 'total loss lubrication oil' in the main, and a bit of the soluble oil that might have separated. In industry it also comes from oils put on stock to prevent rust in storage.

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)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on January 02, 2019, 01:00:35 PM
I'm sure I've mentioned this before.... but I use this stuff: http://www.lubetechshop.co.uk/product_info.php?cPath=25_51&products_id=291

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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 02, 2019, 02:30:38 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:

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 ?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 02, 2019, 04:01:00 PM
My quest was to find a soluble oil that I could use across all my machines and metals, so manual lathe and mill, CNC lathe and mill, and also a cylindrical grinder and a surface grinder with soft and hard steels, brass, aluminium etc. The Castrol Hysol SL 37 XBB  does this and, like the stuff you mentioned, is a bit over £100  per drum.

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:)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 04, 2019, 08:14:27 AM
Yesterday the Tramp Oil Skimmer arrived, so I was able to weld up the 'gallows bracket' to mount it, and give it a coat of the obligatory zinc rich primer and satin black top coats from a rattle can.

(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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on January 04, 2019, 04:26:21 PM
Nice job! What rpm does the skimmer run at?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 04, 2019, 05:23:33 PM
Thanks Tom, I'm guessing 50 - 60 rpm

By the way, the barrels of coolant arrived gone 5 pm this evening so guess what I'm doing tomorrow  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Johnny Bravo on January 05, 2019, 03:29:59 AM
Was good to catch up the other day Andrew. Will be interesting to see the lathe up and running with the Renishaw probe ... :wave:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on January 05, 2019, 04:45:13 AM
What material is that skimmer belt? Long time ago I saw stainless steel foil.

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 05, 2019, 06:24:29 AM
Johnny, yes good to meet up again, and yes . . .the Renishaw Probe . . . PK seems to have gone awfully quite over the past couple of months, I must give him another call next week.  I've had to 'bag up' the cables that should connect to the bits he currently has, to avoid the coolant getting into the connectors and trunking  :scratch:

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 !


 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 09, 2019, 10:32:25 AM
I admit to a nice inner glow and a not inconsiderably swollen head after today's achievements  :ddb: :ddb:

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  !

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on January 09, 2019, 01:16:58 PM
ommmmmmmMMMMMMM - gggggGLOW!

You can go down to nearest town with zipper open carrying a poster: I KNOW HOW TO PROGRAM S5 AND MAKE CHILDREN! :D

Pekka
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on January 09, 2019, 02:33:18 PM
Nice to see you can add to it, my mill just has a manual valve on the front of it I have to turn.




I havenít had a swollen head since that frying pan incident!  :wack:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 12, 2019, 05:38:07 AM
Thanks Chaps!

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 13, 2019, 09:53:44 AM
Still not having the solenoid valves to hand to complete the 'wash down' facility I decided to finish off the alterations to the PLC ladder to prevent wash down when the spindle was turning, or the door open - fairly obviously you can ONLY wash down with the door open and don't want the pump diverted to the gun (which will hang on the door probably) with the door closed.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 23, 2019, 05:43:00 AM
At long last the 24v DC solenoid valves have arrived so I've been able to get a better idea of the volume that they  take up. The various bits of brass plumbing have been to hand for days.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on January 23, 2019, 06:20:32 AM
They would normally be plumbed in to copper pipe which would support them. They're no different to standard zone valves in that respect.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 23, 2019, 07:35:17 AM
Absolutely so Seadog, but not when on flexible reinforced nylon ! So ...... I got on with making a 'flanged 1/2" BSP Tee Piece  :clap:

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 23, 2019, 11:28:19 AM
After lunch I drilled and tapped the machine chassis, and did a test fit of the 'Flanged Tee piece', before screwing all the plumbing together with Loctite 542  onto it, and aligned where they pointed.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 24, 2019, 05:51:18 AM
This morning I fitted the reinforced nylon hoses to the coolant system, pulling the one for the wash down gun under the machine from the rear to the front.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 24, 2019, 10:44:08 AM
Having packed up the RA17 and ordered it's collection I could get back to the coolant isse.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on January 24, 2019, 05:02:06 PM
When I was working in the Dartford Tunnel cutting out the road deck we had trouble with those hoses bursting right next to the jubilee clips. We were using the fire mains as a water supply but right at the bottom of the tunnel the extra pressure was too much for the hoses, but only where the clips were. We changed the jubilees for double-ear oetiker clips and the problem went away. The theory was that when tightening the jubilees it was dragging the top layer of the reinforced hoses round and causing it to tear where the braid was moulded into the hose.

Ever since then I have always favoured using those o-clips instead of jubilees wherever I can.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on January 25, 2019, 05:43:13 AM
   :offtopic:   :offtopic:   :offtopic: 

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? 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 28, 2019, 06:58:23 AM
Now I'm starting to use this machine in earnest  I decided it was time to check and adjust the turret alignment.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 29, 2019, 07:30:41 AM
One step forwards and three back - it seems that my various adjustments to the turret position have disturbed something within, and the turret no longer indexes properly  :bang:

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 29, 2019, 10:03:50 AM
As I thought, the Turret Servo brake was simply powered off the 24 volt DC bus, so I jury rigged a lab supply to pull the brake off, and was able to see the coupling. Getting a screwdriver onto the screws was another matter  :clap:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 30, 2019, 11:49:58 AM
Possible reasons for the Hirth coupling not always being positioned where needed include the Siemens Simodrive Servo Card. However lacking any information on the card I was loath just to tweak away. Posting a plea for help on another forum has sourced the gen letting me experiment with a bit more confidence. The Beaver manual says very little about the turret, but what it does say is the the servo gain will need to be set quite high, but it's description of which pot was the gain is wrong hence not having played with it.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 31, 2019, 06:51:40 AM
Today is the day to set the Tool Disk angular orientation :clap:

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 31, 2019, 11:05:17 AM
All done and dusted. Tool holders re-fitted and tool off set measurements updated.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 31, 2019, 04:28:51 PM
I got the turret covers back on this evening - by heck some of the screws are in awkward places !

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 !




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on January 31, 2019, 04:55:55 PM
Hi there, Andrew,

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? 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on January 31, 2019, 04:59:29 PM
Pete, I've actually got one in a box somewhere, I must dig it out and see if there is room  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on February 01, 2019, 05:51:35 AM
Good work.

...
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 01, 2019, 07:19:47 AM
Yes Pekka it's a real boon having it. Picked it up on eBay many years ago. It uses a non standard battery, so I made up a paxolin block with holes to take AAA Duracells which solved the problem

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 02, 2019, 09:18:50 AM
So Pete-W I dug out the spinning VisiPort, but unfortunately it's not going to be an easy fit. Like all these CNC  machine sliding doors, there is a wiper seal stopping blood and guts getting driven down it's side, and were the VisiPort to be glued to the door, the seal would wipe it off again  - sad but true.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete W. on February 02, 2019, 02:40:45 PM
Hear this everybody:

Never, ever, tease Andrew - he always has the resources to call your bluff!!    :D   :doh:   :D   :doh:   :D   :doh: 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 06, 2019, 06:15:44 AM
The replacement key operated switch arrived this morning, so as it was a quick job it got fitted.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 06, 2019, 06:58:10 AM
Well that was a short live pleasure!

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 !)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Alphawolf45 on February 06, 2019, 10:33:04 AM
 I have 3 of those Swisstac switches broken right now on my EDM.. And I know that the previous owner of the EDM replaced two of the 3 that has broke. I have decided that somebody chose the wrong type of plastic to make them from - too brittle.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 06, 2019, 03:04:15 PM
No, that was just the clip. (And no violence was involved!)

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on February 06, 2019, 04:30:52 PM
Serious question Andrew - is this something you should print, to ensure the material quality you need?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 07, 2019, 03:05:39 AM
The wall thickness of the switch body is the problem I think as its under 1 mm with threads in it as stress risers. I don't think I could print in the detail required.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 08, 2019, 05:18:03 AM
The replacement key switch body arrived in the post this morning and was fitted without drama  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 10, 2019, 08:35:38 AM
I'm still chasing the occasional 'wrong indexing' of the turret when changing tools, so have been chasing my tail looking at the turret servo system in some details.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 10, 2019, 10:05:16 AM
To give me a means of bringing on the turret indexing 'fault' I wrote this little diddy to exercise it - the intention being to give it long and short moves in both directions. It selects tools in this sequence 1,12,2,11,3,10,4,9,5,8,6,7,6,8,5,9,4,10,3,11,2,12 and then it cycles back ad infinitum





Of course I left it running for ages and it never failed  :bang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on February 10, 2019, 03:57:00 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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Pete. on February 10, 2019, 04:08:20 PM
If that thing needs 40 amps to operate why should a little imbalance bother it?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on February 10, 2019, 05:04:21 PM
Have you noticed it always rotates clockwise slightly when locking?
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 11, 2019, 05:34:27 AM
Moray yes I think that you're on to something there. I have long thought that there MUST be some way to set up the relative rotational positions of the Index pulse and the two pairs of Curvic Couplings.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 11, 2019, 06:02:17 AM
Well that last video was pretty useless - out of focus and still from a difficult angle. Hopefully this one is somewhat better:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 12, 2019, 03:08:30 AM
Proof of the pudding will be tomorrow morning when it's cold again I suppose

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on February 12, 2019, 04:43:02 AM
I agree, that little extra move to get final alignment doesnt look right, partly as you say, because the movement is unequal in the different rotations, from my simplistic, completely non cnc point of view, could there be some small amount of slop in the servo drive system, like a slightly loose pulley, or a partially sheared key, caused by the machine crashing, which the alignment system is compensating for, I suggest this because many times in my life, looking for a complex answer to a relatively simple problem has always come back to bite me in the arse, especially if I have assumed that the fault always lies in the most complex part of the system, ie, the damned electronics!
Phil
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 12, 2019, 04:55:52 AM
Now I've roughly tweaked the 'offset' the Curvic Coupling seats nicely each time, so although I agree it could easily have been something 'a bit loose' it almost certainly was that the offset was wrong.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 13, 2019, 07:53:51 AM
Getting so far with the Curvic Coupling seating nicely, I thought I'd push my luck, and re-install the 90 degree powered tool, which weighs literally twice the weight of the other tools.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 13, 2019, 07:58:26 AM
Then we need a wooden mould to pour the lead in. The lead I had lying about had been flashing from a roof, so it had some pitch on it, and the melting was a bit messy producing lots of dross, but we got there, poured the mould and it worked out bang on the right weight :thumbup:

Trying the machine with the turret now balanced, bingo the curvic coupling is again seating nicely, so a successful experiment
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: WeldingRod on February 13, 2019, 09:55:57 PM
That must be one heck of a pocket for that scale!

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 14, 2019, 07:09:00 AM
We don't do 'small' round here  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on February 14, 2019, 11:06:44 PM
It looks like the servo is overshooting?..I've had this on the older Siemens dC drives..it looked just like this symptom. I increased the gain with the proportional gain pot until it settled down.

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.



 

 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on February 16, 2019, 11:39:19 AM
Here is a picture from the Siemens DC drive manual. Not sure if it's relevant here but worth a try  :med:


https://drive.google.com/file/d/1_fheJGFmyK5layWUKvz-G2y88A2-c6_o/view?usp=sharing
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 16, 2019, 11:47:28 AM
Thanks old chap, but if you look 'up thread' I've already fixed this issue - it was the servo 'offset' adjustment.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: cnc-it on February 16, 2019, 12:34:17 PM
No problem Andrew. It's just that I had an Hitachi Seiki lathe that used a proximity sensor to position the turret like the Beaver here but it didn't back off and re position on the notch like yours does, it just stopped when it reached a tool position so that got me confused for a while :doh:   
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JeffK on February 19, 2019, 11:07:57 AM
Hi Andrew

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 19, 2019, 11:43:30 AM
Jeff - not fool at all - they are good machines.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JeffK on February 19, 2019, 01:10:14 PM
Thanks for the quick reply Andrew. From the photos you have posted your machine does look somewhat different to mine. I will do as you suggest and take
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 19, 2019, 01:58:09 PM
Jeff, so long as your axis's are on the 'inside' of your travel limit switches and reference sensors, then winding by hand with the power off should not be an issue. After all that is why you have to pass over the reference sensors to reset the controllers measuring system.

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)

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JeffK on February 19, 2019, 04:45:25 PM
Thanks Andrew - it would be good to have his contact details - though I think I will battle on myself just now as I am still making slow forwards progress.
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RodW on February 20, 2019, 08:17:53 AM
Geez, I finally gathered up the courage to venture into this thread and waded through from beginning to end. What a mission Andrew! Congratulations!

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....
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 20, 2019, 08:26:01 AM
Rod,

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: naffsharpe (Nathan) on February 21, 2019, 03:17:52 PM
Rod, I love your new word. " Slavaged" has to be the best description of refurbishment/rehabilitation of a machine I've ever heard !  Nathan.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on February 21, 2019, 06:04:08 PM
Be kind to him, he's an Australian, and spends all day upside down tangled in the corks from his hat  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RodW on February 22, 2019, 04:25:58 AM
I wasn't sure if Andrew savaged his machine or salvaged it so I had a bet each way  :) :)

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...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 09, 2019, 01:05:50 PM
I've not been convinced that my setting up of the turret was actually spot on. I suspected that checking the turret rotation setting using a flat lathe tool mounting position and adjusting to be parallel to the X  movement wasn't sufficiently accurate, so I made up a test piece.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 09, 2019, 01:21:50 PM
Never mind, I have a boring bar holder with a nicely finished 50 mm outer diameter, so I could sweep round the outside of it just as well as in internal hole.  :thumbup:

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

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on March 09, 2019, 02:48:28 PM
Any updates on the Renishaw probe?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 09, 2019, 03:40:20 PM
It supposedly was going to be posted on 19th Feb but nothing has been received. I emailed PK on Tuesday 5th asking how it was sent but as yet I've received no reply.

All very frustrating  :(  :scratch:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on March 09, 2019, 03:43:56 PM
So what is the purpose of the 3 mm ditch in the turret any ideas?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 09, 2019, 04:21:41 PM
I'd love to know Tom. The only pictures a bit of Googling gives me seem to show circular pockets on other manufacturers tool disks.  :scratch:

I've posed the question on the Practical Machinist Forum so hopefully someone with more experience than I will give us the answer  :med:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on March 10, 2019, 04:49:41 AM
That pocket shape is interesting...If I needed to quess possible logic behind that shape:
* 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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 12, 2019, 09:08:48 AM
I've just spent a couple of very frustrating days bottoming out a fault on the lathe.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: redshift on March 12, 2019, 01:33:36 PM
Will this sort your problem
Regards, Dave
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 12, 2019, 01:50:30 PM
Dave, thanks so much but I've just found one in Holland  :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: redshift on March 12, 2019, 02:20:52 PM
No problem
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 13, 2019, 10:40:32 AM
I started out this morning with the intention of removing the wires from the Klippon Block for input array #3 one by one, and numbering them and replacing to avoid confusion. I had the choice of cutting off the boot lace ferrules, slipping on small number sleeves and refitting a bootlace ferule, or using a larger diameter number sleeve that would go over the existing ferrule, and hold them in place with clear heat shrink tubing. I choose this later approach. The replacement Klippon block isn't due until next week.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on March 13, 2019, 05:39:58 PM
Is there enough wriggle room to pull open the other blocks for inspection without disconnecting all the wires? Isn't it worth sorting out while you are still working there for future peace of mind?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: russ57 on March 14, 2019, 02:39:25 AM
Is that soldering mat like the silicon BBQ/grill mats? Although direct from China might be cheaper anyway..

Russ

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 03:12:08 AM
NRML: in a word no, and then yes in that order!

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 06:13:01 AM
So I cracked on and attacked the leftmost Klippon block - IP1 - moderately populated with 14 wires needing labelling and 5 pre-numbered that need mapping.
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on March 14, 2019, 07:55:44 AM
Andrew, could you rig up some sort of tester to put, say, 1 to 2amps through each connection to see if it broke down,, that would show if you had any more dry joints. Possibly the action of pushing in the plugs helps to cause this problem? What a pain! You could of course leave it as is, because you would know where to look in the event of another failure, but also considering the job or worse that the failure might cause damage to.................I think my autistic nature would make me check them all too! Good luck!
Phil
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on March 14, 2019, 08:21:01 AM
actually, looking at those tracks, maybe 500mA!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 08:24:17 AM
Well Phil, I cracked on and did IP2 Klippon Block.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 10:49:47 AM
On a bit of a roll, I went straight ahead and attacked the first of the digital output blocks OP1. Relatively lightly populated only having 13 wires needing labelling, the rest already bearing sensible numbers, and no complications of 'two in a hole'

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  !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 12:08:43 PM
So after an absolutely marathon session un-wiring, labelling, soldering, testing, and re-wiring Klippon 37 way terminal blocks all five are now done.  :clap:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: seadog on March 14, 2019, 12:44:14 PM
It would suggest that the socket hadn't been fully located before it was soldered. The pins are hardly likely to have grown, are they?  :lol:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 14, 2019, 01:38:59 PM
Well yes they could ! It's a semi flexible structure with a heavy cable attached. I can see it happening if an operation happened to hit resonance in the cable / plug / board assembly. The socket is firmly bolted down to the PCB on stand off spacers, and presumably was so when flow soldered, so I don't think that it's a case of it not having been fully inserted as the bolts hold it fully in.

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!

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Will_D on March 15, 2019, 07:57:07 PM
I remember that ICL (our UK mainframe computer maker in Manchester) tested the large (0.5 x 0.5M) multi layer circuit boards as fitted into the main frame racks. They simulated lorry transport at all the different frequency.  There were some amazing slo. mo./strobe videos of the boards flexing by about 3 times their thickness. These were iirc 13 layer boards and about 6 mm thick fibre glass boards.

And yes they actually recorded the telemetry from a truck driving on roads all over the UK o run on the shaker table.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 27, 2019, 06:42:22 AM
Things are definitely looking up on the Renishaw Probe front  :thumbup:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on March 27, 2019, 02:24:50 PM
Nice they look like they are in good condition.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: kayzed1 on March 27, 2019, 08:00:26 PM
You meet the nicest people on a Honda I mean at MadModder :clap: :dremel:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 28, 2019, 06:33:49 AM
So testing begins . . .

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 28, 2019, 07:51:05 AM
Now to test the OMM.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 28, 2019, 11:27:57 AM
OK so it works as a lash up but it needs installing.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brent Crude on March 29, 2019, 02:12:40 AM
Yayyy! Glad to see things are progressing in the correct direction!!
Quite a project you have there!
 :beer: :headbang:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 29, 2019, 03:27:28 AM
Yes Cliff definitely a good step forwards :thumbup:

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brent Crude on March 29, 2019, 03:15:06 PM
I have exactly the same MP12 here and was able to start it using the OMI I sent to you. I used the same wiring colours as on the piece of paper I included so it may be you have a bit more wrong with your probe as you suspect. I wonder how easy they are to pop open...
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 29, 2019, 06:12:30 PM
I 'think' that the body unscrews. With my smaller probe that was sentenced to transportation, PK made a gripper for the body to unscrew it, and I suspect that the construction is similar, using an 'O' ring seal between he two parts.

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 ! ***
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brent Crude on March 29, 2019, 09:19:26 PM
Iíve seen that too. I think there were two different versions of the MP12. Mine is the same as yours. Mine isnít selling. Iím not fussed over mine. Hey, if you were to give me a silly name, you know the score, it might just appear for the cost of postage!! 🤪😃🤪😃
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 30, 2019, 03:40:49 AM
 :thumbup:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 30, 2019, 04:43:27 AM
Here's a picture of the mystery LED

(Cliff I've sent you a PM)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brent Crude on March 30, 2019, 06:54:39 AM
That LED is the one that flashes green when the probe is on and red when it is triggered.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 30, 2019, 01:03:40 PM
Spent a bit of time this afternoon writing a little program in the Siemens rather arcane '@ functions' to try the probe under program control. As usual all rather unsettling for first time running as you're expecting the probe to be crushed into oblivion any minute  :bugeye:

All went well I'm pleased to say - phew

(The Z co-ordinate is loaded into register R1)




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on March 30, 2019, 03:06:11 PM
Nice to see it work, is it suppose to just probe the one time? On our mill it contacts twice once initially to find the edge within x distance then measures position.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on March 30, 2019, 03:15:59 PM
Tom, that's just a bit of code I knocked up to try it. In real life action you could probe a few times and take an average of your readings if you wished, but this was just to prove to my own satisfaction that I understood the @720 and @371 functions - their description in the Siemens documents is not exactly flowing with detail!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 05, 2019, 10:10:24 AM
So at long last I'm in a position to try and make a VDI40 dedicated mounting for my Renishaw MP12 probe.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 05, 2019, 10:22:23 AM
So reaching for my collet set up on the Colchester Master I was surprised to find they don't go as large as 40 mm :bang: OK it looks like a 4 jaw chuck job to get decent concentricity. In point of fact concentricity isn't at all critical as the probe has four screws to adjust it's position - but if you are doing it, it's nice to do it right !

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 05, 2019, 12:29:02 PM
So, Pigs fed, part cooled in lathe - time to finish the job.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Brent Crude on May 06, 2019, 01:23:36 PM
 :beer: Good work, fella!!
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 06, 2019, 01:48:30 PM
The ironic thing is Cliff, I just tried the MP12 probe and holder in the machine, and the IR of the OMM isn't reaching the window of the probe.  :bang:

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 !






Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 07, 2019, 06:34:47 AM
Sometime these 'Gotcha's ' creep up on you unawares. Looking at the two probes side by side it is dead obvious that their windows point in opposite directions, outwards and left for the LT02S for a lathe turret, and upwards (if in a spindle in a mill) for the MP12

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on May 07, 2019, 04:26:53 PM
Glad it worked out! So why the difference in window direction? Or is that dependent on where the receiver sensor is positioned?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 07, 2019, 04:37:23 PM
The "Wrong" one is intended for the vertical spindle of a milling machine so the window points upwards with the OMM sensor at a highish level out of the muck and bullets.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: tom osselton on May 07, 2019, 05:19:30 PM
Ok thatís what I thought my Son had ours moved from the right side to the left to accommodate the 4th axis on the Haas.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: JHovel on May 09, 2019, 11:42:30 AM
Andrew, reading your exceptional progress with great interest.
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 09, 2019, 12:41:37 PM
Joe, I had considered making a prism that would sit on the existing window but 'look the other way' , but I'm not sure what optically clear (at IR wavelengths) plastics there are that are available, easily machinable, and able to be polished :scratch:

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.

 
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 10, 2019, 10:00:16 AM
So while the first coat of varnish is drying I did an experiment to see if the MP12 probe would work though glass. Casting about for glass in suitable sizes I came to the conclusion that it is surprisingly rare in my workshop  :ddb:

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: charadam on May 10, 2019, 11:24:16 AM
Canada Balsam used to be used for lens gluing, but has been superseded by synthetics.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 10, 2019, 11:42:14 AM
That's the stuff  :thumbup:

Not to be confused with Friars Balsam  :clap:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on May 10, 2019, 05:32:18 PM
Friars balsam smells wonderful. If someone accidentally spills some at work, everyone in the area drifts that way to have a sniff.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 16, 2019, 09:39:05 AM
At long last the sticky backed green baize to line the Renishaw Probe box arrived this morning so I was able to finish it off.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 16, 2019, 09:42:06 AM
And then this morning the baize went on. Knowing this stuff is great fun even on open flat surfaces, I thought that I'd be clever and make a paper template. It 'sort of worked' but this stuff stretches all over the place and when it's 'down' it stays down resisting movement. I'm not entirely happy with the result as it's not absolutely flat in places but it's definitely functional.

Some time earlier I had 3D printed a protective cap in ABS that slips over the actual probe itself, preserving the ruby tip (hopefully!)
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 26, 2019, 10:13:39 AM
When I got this lathe it was evident that the main reason for it's demise had been a leaking Lithium battery used to back up some of the RAM within the controller, and it's leaking fluid had done major damage to the electronics, dissolving away copper track, i/c pins and the aluminium extrusions of the card cage.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on May 26, 2019, 10:27:26 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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 26, 2019, 10:27:59 AM
Now part of the delay in making this modification has been that I wasn't prepared to risk damaging my replacement RAM card, and I had been waiting until another one became available. This happened a couple of days ago, so I went through an exercise of backing up and restoring to the new replacement card and running it for a few days to prove it was OK.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 26, 2019, 10:33:39 AM
Next it was the turn of the C size battery that (very oddly) slid into a holder in the rear of the VDU monitor and was wired from there to the back board  :scratch:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 26, 2019, 10:44:59 AM
 So now we need somewhere to put the box. I made up a shelf that is suspended from the 'roof' of the metalwork that houses the Siemens controller, and is in such a position that the battery holders CAN be accessed from the removable service panel without totally removing the 820T controller, unlike the previous design.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: RussellT on May 28, 2019, 04:43:55 AM
Very neat! :clap: :clap:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 28, 2019, 09:54:29 AM
So yesterday and today I've finished off a job that was started back in November last year, but was put on hold when my Renishaw parts got hi-jacked in Australia. PK still isn't answering emails, but I decided to finish the job anyway.

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 28, 2019, 10:04:11 AM
Then it was a case of removing the original wiring from the MI12 interface, and attaching the three umbilical cords. Once that was done the controller had to be slid forwards to access the interface card that accepts the two probe contact closures, and re-wire it's connector to my already laid in cable.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on May 29, 2019, 06:58:40 AM
Having yesterday completed the outstanding wiring modifications there "SHOULD" be no more need to have the Siemens 820T controller and Operators Panel floating about unfixed as now there shouldn't be any more requirements for access by pulling it out.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 04, 2019, 09:44:14 AM
It was only gong to be a little job  :bang:

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 04, 2019, 09:53:06 AM
So having drawn them up in AutoCAD to see what is what, I then transferred to FeatureCAM to generate a face profile for the jaw nose, deciding to have an initial 20 mm bore to let the boring bar in on the lathe.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 04, 2019, 10:11:43 AM
It was at this stage that I dug out my 'soft jaw clamping fixture' that I  had bought for similar service on the Traub lathe, only to find it was dinky compared to what was needed. I had been sure that it would work, but the difference between a 10" and a 6" chuck is rather a lot !

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 04, 2019, 10:30:26 AM
So at long last boring could commence  :thumbup:

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 !
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 11, 2019, 06:48:38 AM
Some of you may recall that I went to great efforts to mount a Renishaw MP12 probe, only to find that it's optics looked in the wrong direction being intended for a milling machine not a lathe.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: nrml on June 11, 2019, 08:47:55 AM
A sung fitting 3D printed sleeve to go around the probe with a suitable mounting point for the prisms would do the trick.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on June 12, 2019, 09:23:00 AM
Having had all the problems reaching over manually opening and closing the chuck to fit the jaw boring spider when I wanted to bore some soft jaws I went hunting for solutions.

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:




Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 03, 2019, 05:28:24 AM
I've been doing quite a bit of work recently with 1" and 25 mm bar stock, and not been able to use long pieces for fear of it whipping when run at speed. The solution to this is a 'spindle liner' to reduce the internal bore of the spindle to a reasonably snug fit around the stock thus preventing whip.

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 20, 2019, 03:31:54 PM
I was very fortunate recently in that I won for a modest sum a job lot of  VDI 40 tooling on eBay that included a Grippex Bar Puller.

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 .



Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: AdeV on July 21, 2019, 05:23:24 AM
A friend of mine is a CNC machinist by profession, I was talking about bar feeders to him one day, he said - don't bother... just turn up a piece of tube to be a 1 thou interference fit. Put a shallow taper in the front end just larger than your bar stock, so the end slips over. Now mount it in a toolholder. When you want to pull the bar; simply drive the tool onto the bar; release the chuck; pull the tool back the desired distance, close the chuck, then pull the tool off the bar... job done!

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:
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 21, 2019, 06:48:39 AM
The Grippex gripper works on a large range of diameters and also will grip hex. I think mine covers 2 mm to 60 mm without adjustment.

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.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 22, 2019, 08:24:51 AM
Still no parts but at least today I ran the cabling from the digital output, across three cabinets within the existing trunking, bored a 20 mm hole for the cable gland and terminated the cable on the other side of the gland  in an illuminated DIN 43650 solenoid socket ready for when bits arrive.

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:

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 26, 2019, 10:11:20 AM
The Valve and plumbing bits have now arrived so they got fitted this morning

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Johnny Bravo on July 28, 2019, 11:46:10 AM
Great to see it up and running. Should have shouted,I have spare Grippex teeth  :thumbup:
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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on July 29, 2019, 09:51:58 AM
It was evident watching that last video that there was a danger of the coolant hose getting caught on the X axis termination box, so today I fitted a spring loaded support. I've a feeling that there was something similar originally, but can find no evidence on my earlier photos. The coolant pump and filter had of course been dragged from the tank and placed on the box ways (  :bang: ) when I got it, and that would have displaced any existing support.

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.

Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: Sea.dog on July 29, 2019, 12:36:10 PM
I was thinking to mention a support for no other reason than it will prevent eventual collapse of the pipe.
A neat solution.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: awemawson on August 15, 2019, 05:09:44 PM
Just to show I've not been idle, and have been actually USING the Beaver TC-20 here's a picture of two hundred parts I've run off for an acquaintance on another forum. One part is a taper adaptor and the other a simple spacer.

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?
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: hermetic on August 16, 2019, 01:08:01 PM
I built this tumbler for my daughter, from an example on the internet, it is for rock polishing, so you would need to go up a few levels to get enough vibration, but any motor with an eccentric weight attached will do the biz.This uses a computer fan with a 10mm nut and bolt in one of the blades, and you can vary the level of vibration by using different sized bolts.
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: PekkaNF on August 16, 2019, 04:12:25 PM
I concider building one, but bought case tubler - the type reloaders use with corn or peanut husk. Maybe if I had all parts, but would have not got it any cheaper - probably whole lot bigger.

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
Title: Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
Post by: mc on August 16, 2019, 04:19:21 PM
I took the easy option and bought one of these - https://www.frost.co.uk/motor-parts-vibratory-tumbler-rust-remover-polisher-8kg/ as there was nothing else available that size for as cheap.

I made sure buy the media elsewhere though, as Frost was really expensive for it compared to the industrial suppliers.