You should have a nominal KV of 2.0 and you should adjust the gain for about 204.5 and then adjust the drive for a gain of 2.0 when moving the axis. The X, Y and Z axis MUST be matched at a gain of 2.0 when moving _+ 0.01.
The problem with scales is that the motor position is fighting the scale position because of lost motion in the thrust bearings. With a machine about 20 years old, it is time to replace the thrust bearings mostly in the X axis we have found.
The reason you you are having problems on a 45 degree angle is because your servo gain is not matched in the X and Y axis, one axis is moving faster than the other, classic gain mismatch.
MIKE
CNC Machine Services INC | Cincinnati Milacron MachinesCNC Machine Services