Z axis drift

[IainLGrant]

I would appreciate any input.

My wabeco 1210 CNC mill has started to drift upwards in Z. I have lubed and adjusted the gibs and ball screw.

Over 1 - 2 hours of a CNC program running, it will gently drift up over one inch. The machine believes it is in negative Z, but the mill is just cutting air.

The device has servo motors, the collets are tightly gripping the mill.

Any suggestions as to what to do next.

Iain Grant.

[Karl_T]

If you have ruled out all mechanical causes, it must be electrical. The only possiblity I see would be the encoder or encoder wiring and conections.

Don't know if this is much help, just my 2 cents

Karl