Just put it together... Axis's don't know when to stop!

[bobby4718]

Try checking the height of the proximity sensor. If you put the nozzle on the bed, the sensor should be the thickness of a credit card away from the bed.

More detailed instructions here, just do step 2.2:

SM2 calibration

First, you can update the software and the firmware via the following links: Please do as follows to adjust the proximity sensor(for A150 as well): It seems that you need to adjust the proximity sensor and check the platform. Normally, when the nozzle is close to the surface of the printing, there will be a red dot in the nozzle. Please do a calibration process, and record the process to check if the proximity sensor works during the process. 1, Please check if you have assembled the plat…