This is an issue that I debugged at our local makerspace. I couldn’t find much information when I searched the internet on what could be causing this problem, so I thought I would post it once I figured it out.

The problem was caused by the focus lens not sitting tight in the focus lens holder. In addition, you should check if all the mirrors are sitting tight and do not have any room to wiggle around.

If this does not resolve it for you, it could still be one of these things:

  • The belts are not tight enough, and there is too much room
  • The settings you are using are too aggressive (cut jerk, acceleration)
  • Some other mechanical part is lose

Let me know in the comments what caused wobbly lines for you! :-)