Anders Olsson

I did some further investigations and I have to add some corrections: The X-axis never hit the end stop (the belt pulley), but went very close. It appeared like was hitting the pulley when homing though. My fan holders were slightly bent, not much though. Nothing close to the photo previously posted, I doubt it could have made the fan sit more than a millimeter closer to the wall when homing. I was testing it a bit now and fan is still extremely close to the wall when homing, even though the limit switch tab is bent and the fan holder looks like it is supposed to. If I move the head to the home position by hand, fan screws will hit the wall just a millimeter after the X-switch is clicking. If the tab of the limit switch was not bent a bit, the fan would go extremely close to the wall, probably hitting it. The paper squeezed between the fan screws and the wall in the following photo is 0,9mm thick in total. I put it there at the exact position when the X-switch is clicking. Here is my X-switch with it's slightly bent tab: EDIT: Mixed up X and Y-axis

Hi! I've had the same issue on my UM2. It worked fine the first few prints as I can remember, then it from time to time developed an ugly sound when homing the head after the print was finished. It looked like the whole print head bent when homing, but I did not realize that the fan was hitting the sidewall until I read this thread, thanks! :smile: Anyway, I concluded that the print head was for unknown reason not hitting the limit switch when it should, so I just bent the tab of the limit switch a bit so it activates a bit earlier. It is working fine since then. I did not realize the fan was hitting the wall, but I could conclude that the X-travel hit the end stop at he same time as the limit switch was clicking. On the Y-axis, the limit switch activated when there was a few mm of travel left. If this is generally the case at UM2, I would suggest the Ultimaker-team to move the holes for the X-switch a few mm to make this mod permanent. EDIT: Mixed up X and Y - axis