Prusa i3 Printer Slips on X and Y axis

So I have a Prusa i3 by Geeetech, and their customer service isn’t great, so I am asking here.

Recently, 4 out of 5 prints fail because of a slip. 3 of 5 times, it’s the bed (Y axis) and 1 of 5 times, it’s the extruder (X axis). I thought it was the slicer I was using, so I got a new slicer and exported the gcode, but that didn’t help. So I’m pretty sure that it’s the printer, but I don’t know where to start. Any ideas?

  1. Might be failing PSU. Use a multimeter and check the power supply output for 12v.
  2. Might be stepper drivers overheating.
    • Add cooling-fins (if necessary) to the back.
    • Add cooling-fan , to blow across.

I think I fixed it by loosening the belts. I read about the motors slipping if they were too loose or too tight. Thanks though!

Hello @caitlin_le, let use know if your modification has fixed the issue. If not, please send some pictures of the failures as that will help to diagnose the cause.

There are many aspects that could result in a stepper motor skipping steps, or jumping. The cause is lack of motor current to do the job in its current situation. So, what that means is…

1.) Not enough current to begin with, as in, the motor control boards have not been adjusted correctly for the motors they are driving. Less current will equal less torque the motors can provide which would equal having to slow the print speed down to compensate as a slower print speed will equal less inertia that can overcome the motors holding torque.

2.) There could be too much resistance(load) on the motor such as a overly tightened belt or bad bearing or just a heavy axis. If your printer was printing OK before but not now, that could indicate something is failing hardware wise.

If you are positive that you have the power available to the motor and the axis isn’t difficult to move manually, then another thing that you can do to compensate for jumping in a print is lower the acceleration rates in the EEPROM. You should only need to adjust this if you know you have a heavy axis, usually a moving Y axis bed. Generally not an issue with pre-configured printers.

Hello @neilblue

I think I have just fixed the problem. I just loosened the belts a little and it seems to be working fine. Thanks for the solutions!