Steve,
I finished rebuilding my Y axis to be identical to the X, same counts per inch, brackets, etc.. The problem of losing position (thru DMC Smart Terminal) got worse and more erratic! An electrical engineer I consulted with said he has seen this when there is a floating ground. SO I plugged in an extension cord and took an Ohm meter from that ground to the motor body, router, frame, etc, all seemed well grounded. The cable shields connection to my 100 pin break out box were also grounded. The problem was the cable going from the 100 pin break out to the amps was shielded but not grounded, I grounded that reran the test in DMC terminal cutting the same hole 70 times and the size only grew .001. Next in Mach3 programmed a a loop to cut a hole measured it, then put it in a loop to cut the hole 50x, again only grew .001. So the ultimate issue was a floating ground.
For somebody in the same boat of losing position here is a list of things I did when trying to fix this problem.
>Try a test cut in DMC ST or Galil Tools (Problem showed there when I increased AC and SP, which rules out a Mach3 setup). Be sure that you have your Galil setup properly good PID, AC, DC etc and BN.
> Replaced all the cables with shielded and grounded cables.
> Formatted and rebuilt my PC. (probably should have been the last thing I tried, the PC does not have much effect on a Galil)
> Checked and rebuilt my mechanical drive to make it as good as possible.
> Tested the ground of all components. (Found the shield on the cable going to the amps was not grounded, this caused my position loss issue).
All is well now, now I get to cut some cool stuff, can't wait!!
Thank you so much!
Matt