Hey all,
I am experiencing some Z-ribbing after having corrected a layer-offset problem earlier this week on my Ultimaker 2+. The set screws on the belt pulleys had come slightly loose, resulting in prints that look like this.
After tightening the set screws on all of the pulleys, this problem largely went away, although the printer now has a z-axis ribbing issue that wasn't there before. Now the surface of my prints has slight (<1mm), yet undesirable, horizontal ribs in both axes.
So prior to any of these issues (for the past 2 months or so), I noticed that the printer makes a slight squeaking noise that is a bit more pronounced in the y-axis. When I physically move the print head around, there is uneven resistance in the y-axis that increases near the center of the travel between the two extremes. Here is a video of the noise:
https://photos.app.goo.gl/QYNZBZaztJ3jcARY6
Anyway, the noise seems to be coming from the back of the printer-- maybe the stepper motors? It's hard to pinpoint. It looks like they are impossible to get to without disassembling the printer. It looks like disassembly will also cause all of the axes to come loose from the guides. It looks a bit of a challenge to put back together, so I'd like to avoid doing that if it isn't the issue, but maybe there is a guide to doing this somewhere?