What drives do you have on your lathe, black ( Kollmorgan ) or badge ( Siemens ). If you have the rotating tool option then you may have a rotary scale between the spindle belts and the head-stock ( Hiedenhine) or you have a resolver/encoder with a timing belt around the rotating spindle. Check your prints and look at the back of the spindle to tell us what you have. How did you change out the hard drive and who changed it??
MIKE
CNC Machine Services INC | Cincinnati Milacron MachinesCNC Machine Services