I'm quite new so please don't blame me, but I'm into deep problems with the Ultimaker 2+ in our FabLab (Bad Windsheim, Germany).
The axle-rods (the thinner ones that go through the printhead) tend to get loose from the black plastic mounts and then knock on the acrylic side of the case.
This furthermore causes another huge problem: Sometimes the rods fail to touch the end switches after printing and when homing the printhead. -> ERROR: X/Y-switch broken. The printhead can be moved with a small but consistent resistance.
What we've done so far:
- checked belt tension and alignment
- checked stepper belts for alignment
- aligned all axis with alignment tool
- replaced brass bearings with self-lubing (graphite) ones
- replaced axle-mounts (black plastic parts) with new ones
- replaced print head bearings for new (polymer) ones
- tried printing without acrylic door & cage --> same results
- tried gluing axle-rods in place --> got loose while printing
(- tried several filaments --> just to make sure)
(- tried printing with & without OctoPrint)
However, print quality isn't affected at all.
I'd be glad if anyone could help me out! Maybe somebody out there has encountered similar problems or knows somebody who has. I'm happy about any tips and suggestions! If you need (detailed) pictures of the printer to help me out, please let me know.