My filament jamming/plugging fix

[kinggorilla 0]

I have been meaning to post this for a while now, just had those pesky real life issues keeping me busy.

I'm not entirely sure which version of the hotend my ultimaker shipped with, but from the start I had constant issues with the filament getting jammed in the bowden tube and then the extruder would just grind it. I also would occasionally get plugs in the hotend.

Reading through the forum and thingiverse, I saw all the different variants of bowden clamps, threaded tubes, nuts and other devices people had come up with, but I thought there had to be a more elegant and simpler solution.

First off, I switched out my bowden tube from stock to 4mm i.d. and 6mm o.d. This took care of the filament jamming up in the tube. i also installed the extruder drive upgrade from Ultimaker.

Next I looked at the hotend plugging / tube popping issue. I tried a few different ideas, but this is what has ultimately worked for me. Also I never kept track of all the dimensions when i machined things, but you should be able to get the general idea.

To start, I removed the screw and nut on the corner of the wooden box where the bowden tube went to make room for the peek tube that would be going there. Then I machined a PEEK tube that goes from the top of the extrusion head and fits into the teflon insulator. I initially tried to eliminate the insulator, but still ended up with plugs after a few prints. i then threaded the top of the tube, and screwed it into the inside of my bowden tube. To secure it all together, I cut a groove into my new PEEK tube that an aluminum strip would lock into and secure in place when the original thumbscrews were tightened down.

I've been running this setup for a few months now, with *ZERO* jams or plugs. it all clamps together very snugly, but comes apart very easily without any tools when you need to fiddle around with the hotend.

PEEK tube going into insulator

Top of extrusion head, with clamp and bowden tube connection

Same view, different angle

The PEEK tube and clamp disassembled

I think that about covers it... if anyone wants more info I'll try to answer any questions.