I can't figure out why the z axis is always .010-.030 off( short of the physical zero) after I've rezeroed the z axis. Let me explain: I first set the tool and home the machine. Then I bring the z axis to my workpiece, bring the tool to the physical zero, and zero out all three DRO's.
I then re-home the machine and check for accuracy by pressing the "go to zero button". The x and y axis are accurate. The z axis is short by as much as .010. If I repeat the operation, that is, bring the z to the physical zero and rezero the DRO for the second time, the machine will run fine from this point on.
So why do I have this error only once? If it were backlash, I'd see it in the work. The machine runs fine aftewards.
tony