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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 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 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 didnt 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 840T 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)