Hi,

I calibrated Y axis according to maintenance manual. On the way from machine origin south, this reliably lands me on the right spot (traveling 430mm) even after 10 repetitions. When I do the same distance from south to north, with the same Pulse_Y setting, all by using the "execute" button in the "set aligment calibration values" window, it doesn't get back to 0 on the ruler. If I go back and forth 5 times, I end up at >1mm error.

It seems that the calibration value works in one direction but not in the other. What can be the reason? All speeds are super slow (max 2/4) and the machine moves very smoothly.

Thanks in advance,
gj

The problem was as you indicated: the shaft coupling wasn't tight enough. Thank you!