I have a 1993 vmc15xt. I just replaced ball screws in both Y and Z axis along with the thrust bearings and seals. Also a new servo motor on the Y axis. Before the repair, I had this problem in the Z axis. Now I have it in the Y-axis.

If you jog the table in Y+ and then stop, it jumps back .0002. If you jog it in Y- it stays just fine. The fact that it jumps like that to me means it isn't a mechanical thing because that might be with outside force, so something is telling the servo motor to move. I have the back lash setting at zero right now and it jumps that little bit.

Now ultimately, that isn't going to affect my parts at all as I do some rather loose stuff, but damnit, it should be right.

Any idea what might be wrong here?