Servo drive problems

[Tomnewry]

Hi guys I dont know if anyone here can help me but here goes.. The problem I am having is for some reason when i switch on my machine and run the software program the drives just go nuts running up and down the different axis like it's got a mind of its own. It dosent do it all the time only sometimes but more times than not, it runs on three servo drives with encoders on the top of the drives. I have used the machine lots of time with no problems but it's doing my head in I have checked for looses wires but cant find any.
Thanks in advance.

[AdCNC]

Well if all 3 axis are doing it then i will be a problem with whats supplying the signal. so chances are its your board.. what board are you running btw also what software?

[Tomnewry]

Hi the software is amtechs gnc software as for the board im not sure, when i open the controller box there are three mini maestro drive boards and the controller is connected by two scsi cables.
By the way sorry for the delay in replying.
Also i have replaced the wiring from the encoders and its still doing it.
Thanks

[Swarfing]

You talk of scsi cables, is this what connects you controller to the PC? or are you using conventional printer cable to the parallel port? if you are using the later something else may be sharing the interrupt for that port.

[Tomnewry]

Hi the connections are two 37 way scsi connectors which have their own i/O cards in the computer the machine runs fine sometimes and others just goes nuts im thinking of changing the whole controll box if i cant get it sorted, is their any way of checking the drives and encoders before making any drastic decisions.
Thanks

[Tomnewry]

Also the cards are from amtechltd.co.uk hope this helps.

[Gary]

Also the cards are from amtechltd.co.uk hope this helps.

You would be best to contact Amtech.
I dont think the drivers are the problem.

[Tomnewry]

Hi Gary thanks for your reply but i have contacted amtech and they want me to sent them the cards from the computer but its going to cost a lot of money so thats not really an option thats why im trying to see if anyone might know the problem. Is there a way i can run the servo drives from a breakout board and run the cnc from mach 3 or simlair program?
Thanks

[Gary]

Hi Gary thanks for your reply but i have contacted amtech and they want me to sent them the cards from the computer but its going to cost a lot of money so thats not really an option thats why im trying to see if anyone might know the problem. Is there a way i can run the servo drives from a breakout board and run the cnc from mach 3 or simlair program?
Thanks

The driver you have is a very old analogue DC servo driver so the control signals are +/-10V.
Mach 3 and most of the other lower cost CNC controllers send out a step and direction.
So the answer is no.
If you use the machine for production and it being down cost you money, you would be best to just send the boards to Amtech.
I have known Stuart at Amtech for over 15 years and while he will charge you for any work, he is good at what he does and should be able to get you running again.

[Tomnewry]

Hi gary thanks for replying, the machine is only being used for hobby stuff and im in no panic for fixing it i just dont want to start sending away cards to be told the problem is with the encoders or someting else. Hope this makes sense im try to exhaust the less costly options first.
Thanks again