[BillStrahan]

I purchased a 1997 VMC15XT. It was under power, everything worked, and all was well. Then I had it loaded up and moved it a few hundred miles and now having some spindle issues. The first few times I turned the machine on the spindle load meter was bouncing around between 0 and 35% even though the spindle was off. Then when I went to start the spindle (S500 M3) I heard a relay click, some hissing air, and after a few seconds I got "motor overload error 10 C axis" or something very close to that.

I powered everything down and back up a couple of times and tried reseating the cards in the cabinet and looking for any connections that might have become loose in transit. After a few times of that, the bouncing spindle load meter went away, and I was very hopeful...but when I tried to start the spindle it sounded horrible, jerked forwards and backwards at perhaps a few hundred rpm before I stopped it. The errors are gone, but this jerking back and forth and surging motion is all I can get from the spindle at this point.

I tried an M3.1 to ignore the spindle index magnet and that made zero difference. When turned by hand the spindle and motor both sound fine.

I have converted a few mills to CNC, have two Tormach 1100s and at the moment I'm lost as to where to go next. Any help would be appreciated. I can upload a video if the back and forth surging description is inadequate.

Bill

[machinehop5]

...which Spindle Inverter do you have? There are some things you can check. Read more about it in this manual.
https://www.fadalcnc.com/media/pdf/t..._and_Motor.pdf

[BillStrahan]

Thanks, I have the Baldor Small drive, after looking at the document you linked. I think it is the encoder on the motor. I got up there and just played with the wiring, disconnecting and reconnecting and checking for anything loose. After doing that, I powered back up and the spindle came on without a problem. For about 3 minutes. Then it started surging and eventually got an error 9, overload. I'm going to mess with it again as soon as I can get time for it.

[machinehop5]

...the Encoder would be the 1st suspect. I see that Encoder is a US Digital ENC-0007 most likely on your machine.
http://www.fadalcnc.com/media/pdf/te...MC_15_15XT.pdf

https://www.fadalcnc.com/index.php/enc-0007.html
...if, you can access the Disc inside there should be a very small Set Screw on the Disc hub that maybe has become loose over time. You may have to use a special tool for setting the spacing from the reader head. You can see the hair pin tool which I think is what they use. Or possibly the Disc has gotten dirty some how.

Happy Hunting,
DJ