Oh Blimey I bought a CNC Lathe !!!!

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awemawson:
Well I reckon that was a success ! Can now tell what appeared to be just pipe terminations on the spool valves are actually sintered bronze exhaust noise suppressors. Also there are LABELS :wave:

I might even be able to find my way around all this plumbing if things are labelled :lol:

So what next: Well lets see if we can make up some replacement capping for the stuff missing from the electrical tray:

awemawson:
:ddb: Yes that seemed to work - we're on a roll :ddb:

There was no way I could keep 750mm of the plastic conduit hot enough all along its full length to successfully squash it, So I thought I'd try just squeezing it cold in the vice a bit at a time. I expected it to crack - but no it went quite well. Curved like a banana, but straightened up ok by hand after I'd cut out the necessary strip from the back with the angle grinder.

Now need to leave it to completely dry off as meths contains quite a bit of water. Also need to make up the 24v DC supply to go in that empty place next to the transformer.

awemawson:
I spent a little time last night identifying the thirteen wires left disconnected from where the Power Supply is missing. The two red ones are obvious as they emanate from the 21v o/p of the transformer having passed through a fuse. Two more are obvious as they connect to the 0v and 24v inputs to the PLC. Another two are obvious as they connect to the 0v and 24v of all the inductive proximity sensors.

That leaves a further seven wire unaccounted for. Oddly each one goes to the driven side of a relay coil, and also to the relevant PLC output that is driving it. I can only assume that the original power supply must have incorporated a snubber diode for each of the relay drives. If this is the case then the various air solenoid coils which are also driven by the PLC outputs don't have snubbers!

Anyway as the fellow with the original psu isn't answering emails I thought I'd make one anyway. I bent up a little chassis, picked up the existing holes that mounted the original one, mounted the bridge rectifier and reservoir capacitor, and put a 'din rail' on to take din terminals. Although I have some 4mm ones already they are a bit bulky, so I have some 2.5mm ones on order that hopefully will come tomorrow.

Have a few pictures:

awemawson:
The 2.5 mm DIN terminals arrived today, so I've assembled the replacement power supply. A little bit of 'solder sculpture' to wire up the seven clamping diodes for the seven relays, but all went to plan. I only had to extend one of the original wires to fit my version of the power supply, and this was only as I wanted the clamping diodes to appear in the same sequence as they are physically laid out in the chassis. (It makes thing so much easier later on in years to come when things fail!)

Once the power supply was installed I disconnected the 230v AC feed to the transformer, and powered it up from a local mains feed. All checked out OK. The PLC seems to be running its program, and responds as I, for instance, bring a lump of metal up to the various proximity sensors. Can't test it in earnest until I've disabled the various interlocks that would have come from the lathe.

The air plumbing is (slightly) curious. Basically there are two double acting cylinders. One raises and lowers the alloy extrusion that holds the current bar that is being fed. The other advances or retracts the pusher 'lance' that feeds the bar into the lathe. The 'oddity' is that there are three air pipes coming out of the back where the regulators and filters were before the vendor vandalised them. I 'think' that the air enters a filter, regulator, oiler unit, and goes to a pair of spool valves controlling the bar advance / retract. And that a feed is taken from the retract side, via a second regulator, to feed a second pair of spool valves that operate the 'Up/Down' of the extrusion. This would make sense in that it effectively prevents the extrusion moving unless the pusher is fully retracted. There is also a pressure switch on the retract feed telling the PLC that there is or isn't pressure on that side.

Anyway that is the way I'm plumbing it up for testing, though I've had to order another regulator / filter / oiler unit - I had a brand new one but it's a massive 3/4" BSP size whereas all the stuff originally seems to have been 1/4" BSP

Hopefully when that is all fitted I can start testing in earnest.

Have some holiday snaps:

awemawson:
After an enforced delay due to being invaded by hoards of grand children over the last two weeks at last a bit of progress. Firstly a very nice man emailed me a pneumatic diagram for the bar loader, which shows my initial concept was wrong. Turns out that the third regulator exhausts to atmosphere as an 'over pressure' safety device in case the machine pushes back!

This has allowed me to plumb up the pneumatics

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