Geeetech

I am trying to perform the step "Define the final Z axis height". The home button works fine, but after a few seconds of the motor idling the z position will drop a little. If I give it the command G0 X0 Y50 Z2 it will move to the proper position but before I can measure the distance to the bed it will drop again. Any Ideas?

The motor will unlock itself if it idles for a few minutes, you can home the printer everytime before you measure the Z axis.

Is there a way to increase the time it stays locked?

I don' t konw how to do this, but after you home the printer and do the measure again, I think there is enough time for you to measure the height before it drops.
Or is there something wrong with your motor? check the wires if it loose or something.