If your running the Schutte W305 Toolgrinder.
I do machine calibration on my machine (9 hours).
If you move the machine zero, you would have to offset everything else, wheel magazine, probe (zero), software limits.
The machine zero (all axis) is far from random, the zero for all axis is set during calibration with a 3D indicator with a 4mm ball on the probe.
Trust me, you don't want to move that zero position.