Extruder digging into print bed

[butool]

I recently removed the extruder on my PrintrBot simple metal plus (the old one) to clean out a clog. When I reinstalled it I tried a test print. The homing sequence goes fine but as soon as the perimeter print starts the extruder head digs into the print bed. Does anyone know the cause and/or solution for this problem?

Any help would be much appreciated

[RetireeJay]

One possibility is if you have an incorrect Z offset somewhere. The probe sequence tells the machine the Z position where the probe switches state, but then there has to be a correction to get the nozzle to the exact right height. Either the exact physical position of the probe has to be adjusted mechanically, or there has to be an adjustment somewhere in software. I never had a Printrbot with a probe, so I'm not sure how the adjustment is done, but I wouldn't be surprised if there are setting both on the Printrboard (in EEPROM) and also in the slicer that calibrate this offset between probe-switching height and optimal nozzle height. If you have either changed the nozzle or loosened and re-set the probe, you have to adjust this calibration because the offset between the two has changed.

[novice]

M212 Z0.10
M500
M501

Value shown will raise hot end .10 mm, the greater the value for M212 the higher the hot end. To lower a too high hot end, one would use a negative value as example M212 Z-0.10

M500 stores new value to memory
M501 confirms new value

[ktfergus]