4-5mm shift in Y mid print

I am getting a 4-5 mm shift in the Y axis during prints. I has happened twice in a row. First time was about 5.5 mm up and it shifted about 4mm. The second was about 22 mm up and about 5mm. I missed the first one and thought it might have been a belt slip. I was right next to it for the second one and didn’t hear anything out of the ordinary. I just got my printer up and running last week and have been running through some small printed trying to get all the calibrations right. I have done four prints total and the first two this happened on the last two. I used Slic3r loaded it to and printed from the sd card. Any Ideas? Or anywhere I can check to start troubleshooting?

Imported from wikidot

Common problems :

  • Driver chips too hot going into safe mode
  • Pulley slipping around stepper motor shaft due to insufficent tightening ( very very common )
  • Too high accel
  • Too high junction deviation
  • Incorrectly set stepper motor current ( set the *exact* value your stepper is rated for )

Thanks for the quick reply. I took all the pulleys off and ground a flat spot on to them with a dremel tool. I ran another test and got another jump. It was about 5mm and only on the Y axis again. I can’t find info on my specific motors so I emailed the seller and manufacturer in the hopes that I can get a spec sheet.

What would cause the driver chip to over heat? Would it just miss a few steps and continue without a pause? I have the motors set at 1.4A based on a forum post I found on the same part number. (not exactly an ideal source). Also, I have the printer in my garage and it has been pretty cold that last few weeks so I figured that would provide some cooling.

This may be a silly question but is it possible your nozzle is hitting the print? I know sometimes if I don’t use a small amount of Z-lift when doing non-print moves, I’ve had the nozzle contact the print. It’s never been severe enough to caused missed steps in my case but figured I’d mention it.

I had exactly that problem in the X axis - It took me ages to spot it happening. It was due to over-extruding leaving ridges on the surface of the print, which very occasionally would cause missed steps and a shift mid print.