I wanted to share a problem I have recently observed with my Ultimaker 2 that was recently upgraded to a 2+. I did the upgrade a few months ago, and all the feed issues I had with the original machine were solved - until about a week ago. I noticed that more and more prints were failing with a jammed feeder.
The nozzle appeared fine, so I disassembled the feeder mechanism to take a look. When I looked at the idler wheel that pushes the filament up against the knurled drive wheel, I noticed that the bearing has a steel pulley over the outer race of the bearing, and this wheel has a groove in it. However, it appears that this wheel is bonded in place with some kind of retaining compound, most likely a Loctite 680. It is this bond that prevents the pulley from sliding off the bearing. In my case, it appears that this bond was not secure, and the pulley slid from being centered on the bearing, and shifted sideways far enough to drag on the pivot arm. I have a picture showing the problem, but for some reason this forum won't let me attach it. very frustrating that I can't upload a file from my computer to attach directly. The links I have tried to the image don't work.
I was able to push the pulley back towards the center of the bearing, which allowed me to start printing again. I have had to recenter this pulley two times in the last week.
I have contacted the reseller where I purchased the upgrade kit, and they are sending me a replacement part. Thanks fbrc8! If the design appears to be the same parts, I may take the time to machine my own pulley with a shoulder on one side and an internal snap ring on the other side so it can't shift. I had done this same exact modification 4 years ago to my Thingomatic, and it worked well for years.
I just wanted other users to be aware of this potential problem if they have issues with material feeding. Other than this one slight annoyance, the printer has been working great, and the 2+ upgrade was certainly an improvement to an already great machine.
