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homing problem motor wired wrong  

New Member
homing problem motor wired wrong

when i hit auto home it goes to the back left of the build plate i thnk its the wiring it wrong or i need to flip it. any help or suggestions on what to do. i have a prusa bear mk3s with bondtech

This topic was modified 2 years ago by michael.r48
Posted : 01/04/2020 9:32 pm
Eminent Member
RE: homing problem motor wired wrong

If you can, reverse the plug on your y-axis stepper in its socket on the Einsy board and then rerun the calibration process. 

Note - The Prusa supplied steppers have cables with polarized connectors at the einsy board end that only allow insertion in one orientation meaning that the connection cannot be easily reversed at the einsy end.   

If there is an menu or gcode option  to reverse the y-axis stepper motion in the standard Prusa Mk3 firmware then you could use this and possibly save this to eeprom to permanently reverse the y-axis stepper movement until the next firmware update.  Alternative is to create a custom version of the standard Prusa Mk3 firmware (or Marlin firmware) to do this and apply the change to each subsequent new firmware update as needed.

In the case of polarized einsy connectors and no other corrective option, you'll have to flip the physical y-axis stepper so it is mounted facing the opposite direction on the x-axis either:

  • by swapping the y-stepper mount and its corresponding idler mount between the front and back of the bear frame. This will keep the y-axis belt at the same height but may have y-axis stepper cable length issues.


  • by flipping the y-axis stepper motor and its mount upside down and translating it along the x-axis in its current y-axis location to match the current x-axis location of the y idler and belt mount on the y carriage. This may cause the y-axis belts to change their height at the stepper motor end and may also have y-axis stepper cable length issues.



Posted : 02/04/2020 3:48 am