My Prusa i3 MK3 forgot his home position and it now assumes that the Z 0.0 position is right at the top of the printer. I've asked about this in the Prusa forum before and at that time, I accidentally found a solution using Pronterface.
So I am now in the same situation again. The printer head is at the very top. It assumes that this is Z 0.0, so I can't move it down.
Calibrating Z does not help. It will always display
Some problem encounteres, Z-leveling enforced ...
and some time later, it calibrates Z again, resulting in the same problem and so on (endless loop).
The Pronterface trick (pressing the home button) does not work any more. However, Pronterface seems to accept raw G-Code.
Which G-Code command would I need to send to the printer to let the head move down? That would need to be a command that just rotates the stepper motor and does not consider the Z-axis value, so that the head effectively moves to negative Z values.
I have also tried:
- moving the head down manually while the printer was turned off. I'd like to avoid that. It just doesn't feel right. However, it worked after the third attempt and I was able to do a XYZ calibration. However, during bed leveling, it failed and went into the "some problem encountered" state again.