Filament isn't going into the Bowden tube, instead it goes "into the room"

  • The pictures explain my problem. I have already tried to reduce the retraction but that showed no effect. Thank you for your help.

    The effect is a total stop of the print (no material is extruded).

    • Creality CR 10

    • Cura 3.4.1

    I recently added this new feeder aluminium block because the 3D printed stock version was bad quality.

    Filament not entering Bowden tube

    Close up

    Can you also add what _does_ work, what changed since your last good print, etc.

    Does it seem to anyone else that the teeth marks are excessive in the filament, as if the tension idler force is set too high?

    I've always run my extruders at max pressure and haven't seen any issues related to it.

    What printer is this? and is the hotend running?

    @Trish It is a Creality CR 10. The hotend is running. Usually the raft is printed without any problems but afterwards the filament starts to fail.

  • tjb1

    tjb1 Correct answer

    4 years ago

    This is typically caused by resistance in the tube or hotend but in your case it appears to be mostly caused by a very poorly designed extruder. The filament needs to be constrained closer to the drive gear. You may be able to drill out the PTC connector to allow the PTFE tube to reach closer to the gears or print a spacer to fit in between but you need to support the filament in that gap.

    You can try raising the hotend temperature as a band-aid until you can fix the problem, do not exceed 240 C if you have a PTFE lined hotend. Long retractions can also pull molten filament into the cold zone where it solidifies and make extrusion harder.

    As an example, here is a picture of a Bondtech BMG extruder. Note how the extruder constrains the filament path all the way from the drive gear to the hotend entrance. While this example is extreme for normal PLA/PETG/ABS, it is required for flexible filament. A 4mm gap (or closer) should be fine for PLA/PETG/ABS or other hard filaments.

    enter image description here

    Thank you very much. I just installed that "upgrade" extruder (aluminium) and I'll try switching back to the stock version.

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Content dated before 7/24/2021 11:53 AM