Hi AdCNC

The PC I run Mach3 on is down at present so I’m unable to have a play to see if I can help However looking in through the using Mach3 mill pdf on page 6-12 is the following

“Mach3 has the facility to set a lower limit for moves in the Z axis. See Config>Logic dialog for the static setting of this Inhibit-Z value.”

I Hope this is of some help.

Ivan.