I’ve completed the Z only probe with the levelling probe attached to my plate and it completed the calibration process and returned the tool to a position above. I removed the plate and leads and jogged the tool back down and touching the workpiece surface, jogged back up 0.1mm and, hey presto -o.o8mm which I have now set as Z0.
After you have changed a tool go to the Move Window and click on ‘Probing’, and then ‘XYZ Probe Block’ for Z-only (or if you are using the newer release candidate, you can setup and use the simpler ‘Z Probe Block’) whenever you need to zero a tool: