Filament Pops out of Bowden Extruder Feeder

[jlittler 0]

Hi There:

I have an Ultmaker 2. I am experiencing a frequent and very frustrating issue where the Filament Tube pops out of the top of the bowden feeder. It does have the white plastic tube "holder" thing and the blue plastic retaining clip. When the tube pops out the filament just collects above the feeder and the extrusion fails. I'm using 2.85mm ColorFab PLA.

Other than this issue the printer works absolutely fine. I general the issue happens during long prints. Any suggestions would be welcome!

[gr5 2,268]

The white part has 4 little knives in it. By now they have scraped your bowden tube smaller. So the first step is to remove 2mm off the end of the bowden such that the knives bite into fresh bowden. Then use proper tighten technique below.

How to tighten bowden into head. First remove without scraping it.

1) Loosen the 4 thumb screws 3 full turns.

2) Remove colored C shaped clip

3) Make sure bowden is a bit loose (moves up and down slightly.

4) Push down on outer part while lifting bowden tube.

5) Optionally cut off 2mm

Reverse process:

6) Push bowden all the way in - make damn sure it's all the way - if you have an aluminum spacer above your teflon part then move bowden up and down 20 or 30 times until you know where that aluminimum part starts and ends and you are seated all the way. If you just have a spring - yay - you can see if it is seated in the white teflon part (look carefully at this as you insert as the bowden can easily get stuck on the rim of the white part also!

7) Hold bowden down while lifting clip with other hand (finger nails? needle nose?). Now while holding clip up, let go of bowden and tighten the 4 thumb screws so that the bowden is in tight. At this point you should be able to push up and down on the bowden with 1 kg force and nothing should move.

8) Put the C shaped clip back on.

To test, try lifting your printer up in the air by the bowden or at least lift with 5kg force. The feeder can force about 5kg only (UM2+ I'm guessing 10kg?) The printer probably weighs about 5 to 10kg.