Todays Job On A Nice Little Lathe!

[Sidewinder]

Got a job today on a copy lathe, YOM, 1972!

Used for turning profile rolls for a steel mill.

LVDT acting as the profile follower, analogue electronic rack interfacing with the profile follower and controlling the (retrofitted) CT Mentor II drives & dc brushed motors on the carriage and cross slide.

Was originally all Siemens, as it is a German machine, the drawings are not perfect either, but they did have some!

Found an analogue output out of balance on the drive speed controls, so getting one of the bench guys to look at that now, then we'll see what comes along after that.

No pics of the machine, but I did take some of the panel & control just because it was that old!

I may be going back tomorrow/Thursday to refit the control card & try & get it going, I'll take some more pics if I can, it's only a small machine!

Forgot to say, in the pic of the control, on the RHS the last 3 connections on the terminal rail are 3ph!

Not what I expected until I read RST on the terminal labels.

 

[Marvo]

Wouldn't be surprised if it runs. Somebody has been giving it some love over the years by the looks of things.

 

[NozSpark]

Jeez... those slot in cards remind me of some of the old harrier (mk3?) stuff that I have worked on.... newer than the Buccaneer stuff though

 

[Andy™]

probably more reliable than a new one

 

[Sidewinder]

It was running Marvo, sort of the speed command signal for the drive speed / direction, derived from thh +/-10V is skewed.

The saddle drive is running slow in one direction, and the drive is showing an alarm light, even though it carries on running.

The control boards are all through hole discrete components, none of this ASIC surface mount stuff!

 

[SLIPSHOD & SLAPDASH]

Got a job today on a copy lathe, YOM, 1972!

Used for turning profile rolls for a steel mill.

LVDT acting as the profile follower, analogue electronic rack interfacing with the profile follower and controlling the (retrofitted) CT Mentor II drives & dc brushed motors on the carriage and cross slide.

Was originally all Siemens, as it is a German machine, the drawings are not perfect either, but they did have some!

Found an analogue output out of balance on the drive speed controls, so getting one of the bench guys to look at that now, then we'll see what comes along after that.

No pics of the machine, but I did take some of the panel & control just because it was that old!

I may be going back tomorrow/Thursday to refit the control card & try & get it going, I'll take some more pics if I can, it's only a small machine!

Forgot to say, in the pic of the control, on the RHS the last 3 connections on the terminal rail are 3ph!

Not what I expected until I read RST on the terminal labels.

2014-02-18 11.02.03.jpg

2014-02-18 11.02.12.jpg

Maybe domestic smokes work in the same way  :B-

 

[SPECIAL LOCATION]

Maybe domestic smokes work in the same way  :B-

Nahhhh...

No HUSH button!

:coat

 

[ProDave]

It may be a "little" lathe, but it looks like the control cabinet is probably larger than the machine?

That brings back memories of tuning brushed dc servo systems by twiddling individual trimpots on the boards.  None of this plug it into a PC lark.  Hook an oscilloscope on a couple of testpoints to see position and velocity signals to help tuning.

 

[Sidewinder]

The little bit was a bit, tongue in cheek PD, the chuck was about 1.5m diameter, it was for turning steel rolling mill rolls.

Bed length about 3m between centres.

The headstock was about 2m from the floor to the top, IIRC it was around a 90kW motor, didn't take note to be honest as it was not the headstock that was at fault.

They were dc brushed servo motors with CT Mentor II drives (retrofitted in).

Yes the controller did, have the test points and pots for tuning, the drives were a bit more digital though.

Also, no position encoders as the positioning was done off the profile follower.

The guy I had training with me yesterday went back & refitted the card today, I was busy, after the bench guys had found & fixed a fault.

Machine working, so it looks like it was a fault related to a skewed OP Amp circuit.

Me, I've been building water filters, doing a medical survey visit, and a pneumatic fault closer to home.