ACRAMATIC 850SX Z Axis Loop Open Fault 106

[jimhuffman1]

I am trying to repair an old Milicron machine with a ACRAMATIC 850sxMC CNC controller.

This thing has been abused badly & I have finaly gotten it about ready to run but I can not find or get rid of the fault #106 Z axix loop open. I have even gone as far as to replace the drive, controller & I/O cards with known good ones.

Milicron has been unable to find the control drawings and manuals for this machine so I am having to do everything the hard way. The last guys who worked on it used a set of drawings for a totaly diferent machine heaven knows what has been changed or done that I have not found yet.

Any ideas, hair brained schemes. wild thoughts or experienced help would be greatly appreciated.

Thanks

[Al_The_Man]

Try swopping the X & Z axis encoders, they are probabally the same resolution. That would eliminate that as a source of the problem.
If it stays on the Z, check the cabeling back to the control.
Al.

[DAB_Design]

I've ran several 850 controls, but have never come across that error. But I agree with Al.

[jimhuffman1]

Thanks Guys...I have allready tried swaping all 3 axis motors & encoders with ones from a running machine. (older Milicrons will call a z axis fault sometimes when it is on another axsis).

Darn thing is driving me buggy

[jimhuffman1]

Well this is one for the "who woulda thunkit" file..

The problem with this machine was I aquired 4 replacement boards (old but still sealed in the box) and all of them had the same defect in the board.

Oh well at least I found it while I still have 1 or 2 hairs left on my head.

Thanks Guys.

[neluxu]

hi,
I had the same problem with my machine when I bought it.
There was a undervoltage after the secondary of the second transformer. It was rewired from 480V to 230V (208v) ? That was my problem, I rewired just the transformer on the top (main) everything started up and seemed to be normal (panel powered up, working light was bright but still some errors on DUMP board LED) but I couldn't get rid of the z-axis open loop error. After I rewired the second transformer (you have to jump some connectors, should be a diagram on the transformer) I got rid of the error and everything's working just fine.
I hope this help.
Good luck