UMO(+) Ultimaker Original+ filament always deforms inside PEEK/teflon coupler/brass pipe

[ansonl 19]

Occasionally my UMO+ extruder head gets PLA filament clogged between the teflon coupler (D), PEEK (E), and bowden tube. When I do an atomic pull at 80-90C, I always get a deformed bit of filament about 3.5mm from the tip of the nozzle (see picture). This seems to be at the space within the PEEK where the teflon coupler above stops and the brass pipe (C) that screws into the bottom of the PEEK stops. The filament is always forms an offset notch that I can't seem to get rid of even after disassembly and verifying that the teflon coupler is perfectly round and the brass pipe is screwed in until it is stopped from further screwing in by the flange on the brass pipe. 

 

The clog I am experiencing stops filament from extruding during a print and it seems like the filaments gets stuck where the notch and no longer keeps feeding to the nozzle. The remaining liquid filament drips out of the nozzle and an air gap is left in the new void in the brass pipe and nozzle. The heat then travels up the stuck filament and it expands and gets further stuck in the bowden tube where meets the teflon coupler. I print PLA at 205-210C and the clog seems to occur more at the higher temperatures but not reliably predictable. 😞

 

So I actually have two questions:

1. How can I prevent this clog?

2. Is the filament's deformed notch normal for the UMO+? It doesn't look right for retraction. 

 

Thanks. 

 

[Tim_08082001 0]

Hi

I had the same problem with my Ultimaker Original printer.

In my case the screw of my feeder tensioner was loose.

So the feeder wasn t able feed the nozzle.