I have plenty of the same part to make. More than I can cut in a day. For starters, my system is a C32 board from CNC4PC that is fed from an ESS. This goes out to my Dugong DG2S16035 drivers to my 26Lb/in servo motors. This is all on a Bridgeport Knee mill that was originally made as a CNC. My problem is that after setting my Dro's as Persistent DRo's and deactivating the zero upon home feature ( how come that doesn't stay off all the time when the check turns to an X???). I have to deactivate the zero upon home so that when I home upon machine start up, which if I don't, the soft limits have a hissy fit, I won't lose my position on the dros. I need all that because after all, if the dros stay the same I will maintin the same part Zero. Well, the problem is this, after all that trouble, say every twenty parts or so the position moves by about .010" it seems in X and Y axis. I am running at a fairly low MMR and an average speed of around 15 IPM, 3100 RPM, .514 Axial DOC and .032 Radial DOC w/ a 3/8 carbide 4 flute e mill. If there is anything I can do about my zero being lost I would appreciate it. I have little oscillation in my system, My servo drivers max error is 1500 steps, my encoders are set to 512 PPR and the encoders are read in 4X mode.