UM2 and IRobertI feeder - filament snaps behind bearing

[reibuehl 42]

Hi all,

 

I use IRobertI's feeder (https://www.youmagine.com/designs/alternative-um2-feeder-version-two) now for many years but recently experience an annoying issue: Suddenly, sometimes after a few layers, sometimes very far in the print, the filament snaps behind the bearing in the feeder and then can't be moved anymore. This seems to happen more frequently after I change filament but that might be unrelated.

 

I already printed new feeder parts and replaced the bearing but nothing seems to help.

 

Has anybody that uses this feeder - or any other feeder - experienced a similar issue? How could I fix this?

 

Reiner

[Curven 28]

Hello, do you use an Umlimaker 2+

We experienced this issue on our almost nex UM3 (same feeder as UM2+) at work, tried cleaning the feeder, changing filament, changing tension in the feeder but it always came back sooner our later... Finnaly we had to send our machine to the resserler to get it fixed and now every thing is OK.

 

Sorry I can't help more...

[reibuehl 42]

No, mine is just a regular UM2 (no plus). It is also a fairly old machine (>5 years I think), so no warranty anymore.

[Curven 28]

Yeah sorry actualy just noticed that if you have the IRobertI feeder you muste have the UM2... Sorry about that...

 

You could try this piece here :

https://www.youmagine.com/designs/mod-to-lrobertl-feeder-enhancement-yoke

 

One of them has a guide for the filament.

[shurik 87]

After a while, the yoke and maybe, some other parts become distorted and bent.

I just keep another set of Robert's feeder details and replace them from time to time when their time is due.

After printing a replacement set, you may disassemble the feeder and almost certainly some parts will look worn out.

[reibuehl 42]

I already did try replacing the parts... that didn't help. The current parts only have a few hours on them.

 

[Curven 28]

Did you try different filaments?

Old PLA can get hard and difficult to push trough bowden and the melt and extrude. If there is to much resistance it could end up by deviating the filament where it can...

 

Before we upgrade to UM2+ I used this feeder, based on IRobertI . 

https://www.youmagine.com/designs/yet-another-ultimaker-2-feeder

 

The guide included helps to stretch the filament and so it goes in the feeder with a smooth angle.

[reibuehl 42]

I see this behavior with new filament and old filament. I have now printed and installed the yoke version with the guides that you mentioned and will give it a try for a while. I modufied it slightly to work without the need for spacers and longer screws and have done one successful print up to now. But since the issue only shows up sporadic, I need to test with that yoke version for a longer time.