RE:
same problem here with my Kit Core One received sept 15 2025 : random calibrating/homing/bumping XY to front corner .... some times it bounce 5 times ... sometime endless bumping
--Gantry is perfectly align -- done belt tension adjustment multiple time = OK -- still have random calibration/endless bumping -- extended homing also create bed over heat when you ask chamber temperature to reach higher setpoint : initial bed set point is 115degC when chamber need to pre heat
Open a prusa chat for help , keep telling me to adjust belts ! Belt adjustment should not be a science project !!! the tolerance for this initial X-Y homing/calibration is simply too tight ! all my prints are OK so this initial calibration/homing have impossible tolerance to achieve ... Prusa is not interested to change this in the FW so i'm stuck with my expensive unrialable printer because return shipping would cost too much 😡
Printing since 2019 , Ex MK3s owner , current Core One owner
RE:
same problem here with my Kit Core One received sept 15 2025 : random calibrating/homing/bumping XY to front corner .... some times it bounce 5 times ... sometime endless bumping
--Gantry is perfectly align -- done belt tension adjustment multiple time = OK -- still have random calibration/endless bumping -- extended homing also create bed over heat when you ask chamber temperature to reach higher setpoint : initial bed set point is 115degC when chamber need to pre heat
A mistake I kept making in the first couple of weeks was not fully understanding out how belt tensioning affects gantry squareness. Prusa need to do a better job of explaining this because I feel it is a source of a lot of frustration. To start with, the gantry needs to be square with the belts completely loose. Next as the belts are progressively and evenly tightened, squareness needs to be periodically checked. After completing the tensioning process it needs to be checked again. My view is that Prusa should redesign how the gantry is attached to the y-axis smooth rod bearings.