3D Printing

Normally slopes on my prints look fine, but recently I’ve been getting bad extrusion on some prints but not all. Same materials, same print file. Could this be one of the motors starting to fail? Printed on an ender 3.

Edit: so changing the POM wheels did nothing. However, I did notice while printing the layers weren’t cooling as much as they should before the next layer started. So maybe there could be a fan issue.