The jerk.
Darren.
Because you can feel the jerk, I suspect there is some backlash compensation turned on that needn't be.
It works like this.
Say the backlash compensation is set to 0.002", then when you change direction, the screw will reverse (by the 0.002") instantly, just as you are measuring.
This is setup in the CNC machine setup. I don't know this unit, but it looks like the experts are on hand.
Neil.:cheers:
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.