Thanks for drawing the crown, using my gcode eliminates a lot of variables and really makes it a bit easier. I know for the king of drawing my crown if probably a bit…boring.
Okay, I see what you are getting at. The first two things to check are the pulley and the wire connections. For the pulley if it is loose it will be able to be pulled of the shaft, but usually still works just moves a few mm in each direction. As for the wire connections, triple check them.
A minor thing I see in the first video is some built up gunk on your belt bearings. That can cause some wobbles in your pen but most likely has nothing to do with it.