Z axis moves below set zero

[magicniner]

My point is that so many half-informed attempts are made without a clue that double checking is always a good idea, even if you think you got your maths right, before assuming your software or hardware is broke because things don't do what you want.
I would never run a mill without checking some moves with a pointer on a rule then with a dial gauge and blocks, some might trust that the pitch of their screw is perfectly as advertised, I like to check actual movement.

[JAZZCNC]

I would never run a mill without checking some moves with a pointer on a rule then with a dial gauge and blocks, some might trust that the pitch of their screw is perfectly as advertised, I like to check actual movement.

Couldn't agree more on checking. Can't tell you how many times I've seen cheap drives with wrong Dip switch markings.
However to get the OP issue they would have to be massively wrong. Plus Mach's Auto Steps per option does a very good job of getting right provided accurately measured.

What his problem is I've no idea because is replies are much use fart in space suite.!