Just about all of my prints have these lines at around the same heights, and I can’t figure out why. I tried changing the nozzle, changing the layer height from 0.15 to 0.12, and changing the speed from 60mm to 40mm. All of these seemed to have helped a bit, yet they remain. I was thinking maybe as the prints get to a certain height, the shaking of the bed (Prusa MK2) caused the layers to be slightly offset perhaps. Anyone have any other ideas?
It could be skipped steps, a warped Z axis, lash in the axis. It doesn’t look like ringing to me.
If your steppers run too hot or against too much resistance that’d be the first thing I’d check. As well as give the axes a bit of a yank and ensure it’s all to the German spec.