The Craftmans Shop > New from Old

The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)

<< < (15/254) > >>

awemawson:
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

seadog:
Ok Andrew. Glad you sorted it.

awemawson:
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.

awemawson:
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.

PekkaNF:

--- Quote from: awemawson on June 17, 2018, 01:11:54 PM ---.....
I wanted to prove the PSU was OK but only the +5 volt output had test points. I was fairly sure that it also was supposed to put out +15 v and -15 v.  Pulling the PSU apart it's only output connector is a three row  96 pin Eurocard type. I was surprised to find that mains for the 240 volt rack fans is routed via this connector. Inside I found a pair of 15 volt regulators confirming my suspicion, and also a Ferranti Uncommitted Logic Array - in a PSU for goodness sake WHY ?
....

--- End quote ---

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

Navigation

[0] Message Index

[#] Next page

[*] Previous page