My Smoothieboard-driven OX Openbuilds CNC is coming along great.
I have connected proximity sensors to X&Y, allowing homing to work exactly as I want.
BUT, I just connected a floating Z-plate to allow me to home Z to the top of stock.
What you do is place the conductive plate on top of the material you are going to machine. The cutting tool grounds the plate, which is connected to Z-min making a Z-min endstop detection. This, combined with a Z-min offset of <the thickness of the plate> works great for setting the Zero point perfectly.
Unfortunately the home button G28 homes XY&Z when a Z switch is enabled. I absolutely cannot do that as the Z might crash through the stock, the fixings or even the table! I have to Home X&Y, and then manually position Z over the stock before homing. So what I want is:
G28 homes X&Y only
G28 Z homes Z only
Is this possible?