Churchill Computurn 290 retrofit (again)

[Hood]

Never rains but it pours eh? :/

Good stuff on finding the issue from yesterday though

Yes and you were more or less correct in your assumption as well as it was indeed looking for a serial connection

 

[eSCHEn]

Yes and you were more or less correct in your assumption as well as it was indeed looking for a serial connection

I wasn't going to say that as I'm humble but I was chuffed inside if I'm honest

 

[Hood]

I wasn't going to say that as I'm humble but I was chuffed inside if I'm honest

I reckon you sneaked North the day before I put the mains to the machine and swapped the parameters around just so you could feel chuffed




Oh also meant to add that yesterday I tried out the limit switches and when I hit them the control will not let me jog away in the opposite direction. I had hoped that would not be the case so I will probably have to run new wiring for them at some point. I have set up soft limits just before the hard limits so I should never hit them anyway but if I do I have found if I use the MPG to try and jog off of them it will move small amounts in between each reset until after a dozen or so attempts it has cleared the limit switch. That means it is not urgent to do the new wiring but I will do it at some point as I would like it to work correctly.

 

[eSCHEn]

I reckon you sneaked North the day before I put the mains to the machine and swapped the parameters around just so you could feel chuffed

Would I do a thing like that?

Oh also meant to add that yesterday I tried out the limit switches and when I hit them the control will not let me jog away in the opposite direction. I had hoped that would not be the case so I will probably have to run new wiring for them at some point. I have set up soft limits just before the hard limits so I should never hit them anyway but if I do I have found if I use the MPG to try and jog off of them it will move small amounts in between each reset until after a dozen or so attempts it has cleared the limit switch. That means it is not urgent to do the new wiring but I will do it at some point as I would like it to work correctly.

Ahh yes I have hit (pun intended) this scenario before. You need to take into account the direction of travel before you check for the limit stop. Sort of not how you do it as it's natural to make the limit check the first thing you do to save it ploughing into something.

 

[Hood]

The limits are all wired in series, bioth positive and negative. I spent a few hours earlier in the week gaining access to the connection boxes with the intention of splitting them out to positive and negative like the control was wanting but eventually after a lot of tracing wires I found it would require me running some new wires so I decided just to leave them.

Looks like I may be doing the limit rewiring sooner than I thought as this afternoon has not gone well. There must be a problem with the machine side wiring as when I tried the spindle again the limits would flash and the turret unclamped/clamped rapidly several times and even attempt to index. I think some I/O may also be shot on the control. Looks like there may be a problem with the wiring down to the solenoids and possibly it has put 110v into the control

Not been a great day, started off good but went down hill rapidly, to cap it all off it is probably why I was having random weird issues with the last control and likely I could have just rewired the machine side and all would have been ok. I suppose the wires are about 35 years old so can't complain too much and at least I will be able to thin out the amount of wires as I will not be using half of the ones that are currently in there. I wonder if I can also get 24v solenoids to fit the valves as I am just not keen on the 110v ones and this has proved the point.

 

[rory1]

Yeah that was me I can help out with Mitsubishi software (an older version so no good for their later models) if anyone needs it.

@daleyd , I've got a pair of Mitsubishi fx-1s plc's that I've been hoping to use in a project but I've been unable to locate any software..... would you have anything for programming them?

Sorry to hood for hijacking the thread.

 

[awemawson]

The limits are all wired in series, bioth positive and negative. I spent a few hours earlier in the week gaining access to the connection boxes with the intention of splitting them out to positive and negative like the control was wanting but eventually after a lot of tracing wires I found it would require me running some new wires so I decided just to leave them.

Looks like I may be doing the limit rewiring sooner than I thought as this afternoon has not gone well. There must be a problem with the machine side wiring as when I tried the spindle again the limits would flash and the turret unclamped/clamped rapidly several times and even attempt to index. I think some I/O may also be shot on the control. Looks like there may be a problem with the wiring down to the solenoids and possibly it has put 110v into the control

Not been a great day, started off good but went down hill rapidly, to cap it all off it is probably why I was having random weird issues with the last control and likely I could have just rewired the machine side and all would have been ok. I suppose the wires are about 35 years old so can't complain too much and at least I will be able to thin out the amount of wires as I will not be using half of the ones that are currently in there. I wonder if I can also get 24v solenoids to fit the valves as I am just not keen on the 110v ones and this has proved the point.

I feel your pain Hood, these set backs can be very frustrating and sometimes not a little expensive !

 

[daleyd]

@daleyd , I've got a pair of Mitsubishi fx-1s plc's that I've been hoping to use in a project but I've been unable to locate any software..... would you have anything for programming them?

Sorry to hood for hijacking the thread.

We can probably sort something out, drop me a pm Rory

 

[Hood]

@daleyd , I've got a pair of Mitsubishi fx-1s plc's that I've been hoping to use in a project but I've been unable to locate any software..... would you have anything for programming them?

Sorry to hood for hijacking the thread.

Not a problem

I feel your pain Hood, these set backs can be very frustrating and sometimes not a little expensive !

Yes, it is the expensive bit that worries me.

Just away to head down the road again and get the numbers off of the solenoids to see if I can get 24v equivalent ones. Will also try my best to test what I/O is working and what is not. I know at least 3, possibly 4 Inputs are gone and at least one output. Inputs should be easy enough to test as all I have to do is short them to 0V, would be much easier if there was someone else there to watch the screen whilst I touch the wires but will just have to hard wire them then go round and have a look. Outputs will be a bit more tricky as I will have to write some macros up to test them. If it is just the 4 Ins and 1 out then it is no big deal but I think the Limits may also be shot and I am not sure if I can reconfigure them to other inputs.

 

[Parm]

Good work @Hood, interesting to read and see your multitude of skills

But my head hurts with all that computery stuff

 

[eSCHEn]

Damn Hood that is crappy if that is what's happened. I would have thought you could get a lower voltage coil on the solenoids you certainly see ranges of voltages on them for valves for gas and water.

Not much help but from down here.

 

[Hood]

Good work @Hood, interesting to read and see your multitude of skills

But my head hurts with all that computery stuff

Aye , expert in frying electronics

Actually it is not as bad as it first seemed. I am just back from the workshop, again, and I removed all of the connections in the cabinet for the solenoids/limits/turret and all the Inputs seem to be working when testing by grounding them, even the limits, so definitely something weird going on in the machines wiring. Not tested the outputs yet but I know others are working so at worst I will have a couple blown and enough spares.

Damn Hood that is crappy if that is what's happened. I would have thought you could get a lower voltage coil on the solenoids you certainly see ranges of voltages on them for valves for gas and water.

Not much help but from down here.

As above not as bad as feared but I am definitely going to get new coils if possible.
I know nothing about them but I will go and do some searching. They seem to be the same on the turret and the chuck so that is probably a good thing, pic below of them, hopefully I can get coils and not have to replace the valves. I need 2 for the chuck and one for the turret, that will mean I can dump the 110v supply as the only other thing working from that is the oil cooler fans and I should manage to get 24v ones easily enough.

Coil from the Chuck valve.

Coil from the Turret valve.

 

[eSCHEn]

Excellent news they're not blown

Looking at the VA they don't seem high power so dropping the voltage should be possible. Obviously need to be available and all that. Just had a quick look and yeah this is about the same sort of thing but with a 24VDC coil, sold out though but shows it's available - https://www.ebay.co.uk/itm/Rexroth-Hydronorma-Solenoid-GU35-4-A-426-/292143985261

 

[Hood]

Yes, found a few as well but they are all out of stock so maybe not available any more. Bit pricey as well, might just have to stick with the 110v ones with new wiring as I have spent enough lately

 

[awemawson]

Do the coils remove easily?

If so measure the bore and length and find a replacement 24 V coil of approximately the same VA rating that matches mechanically and it should work.

 

[Hood]

Not sure as I never looked too closely at them but looks to be, from the pics, only 4 cap screws holding them on.

 

[daleyd]

Yes, found a few as well but they are all out of stock so maybe not available any more. Bit pricey as well, might just have to stick with the 110v ones with new wiring as I have spent enough lately

Can you not fit interposing relays to isolate the 110v from your control system, to avoid the possibility of feeding the voltage back?

 

[Hood]

Can you not fit interposing relays to isolate the 110v from your control system, to avoid the possibility of feeding the voltage back?

They are worked via relays but there seems to be a fault in the wiring down to the solenoids so the relays are not much help in isolating things. I suppose with new wiring it would be fine, it has lasted 30 plus years and if it lasts that again I will be long buried so won't be caring. Just not keen on high voltages on the machine itself out with the cabinet.

 

[Hood]

I think I will probably just have to keep the 110v coils. Well not so much have to but rather that I might as well as no point in spending money when not needed.
The main reason I wanted to swap was to do away with the 110v supply. The fans are 110v as well but I could easily get 24v ones cheap enough but I have just remembered that the oiler for the axes is also 110v and that would not be so cheap/easy to replace so I will still need 110v down to the saddle so might as well just keep the 110v solenoids. I will replace the wiring down to the solenoids and also the limits wiring and will rip out all of the wires that are no longer being used. I think I will use SY cable for the 110v rather than the single wires that are used at present.

 

[MCKDAVID]

aye sounds like the best option, cleaner with cables too, especially if you have cutting fluid getting sprayed around in the chamber. As long as you can get the cables into the solenoid coils covers? Had a few battles over the years trying to terminate cable cores into next to naff all space..... As Dale said, isolate them to their own subsystems by interposing relays, fed from their own individual fuse protection that way you can segregate them away from the control circuits completely. Safer and would probably make fault finding easier too.