Is it possible to use Gcode to set a floor for the Z axis, below which it will not travel? A bit like a soft microswitch which sets the lower Z limit.

I want to stop the Z axis descending to where it could gouge the table.

I think the only foolproof method is a mechanical endstop possibly tripping a switch which disables the axis drive.

(When using my vacuum table I use an adjustable (preset) mechanical stop but I have my Z axis drive current set such that no harm will come to the machine if the endstop is accidentally hit).

Tweakie.

The "Soft Limits" setting does this for X,Y,and Z.