Clearing the Bowden Tubes




  • 2mm hex key (if clearing the fiber Bowden tube)


Note that some images in this article feature the A3648 plastic extruder; for more information on different versions of the plastic extruder, see the A3016 and A3648 Plastic Extruders support article.


Unload Material in the Bowden Tube

When loading material after the previous spool has run out, you may need to remove any leftover filament that may remain in the tube between the extruder motor and the print head. This process involves extracting filament from the Bowden tubes and heating one or both nozzles to release the melted material from the print head.

  1. Select the menu icon from the dashboard.

  2. Select the Utilities tile from the available options.

  3. Select the Manual Control tile from the available options. 


  4. Select the Temperature Control tile from the available options.

  5. When prompted, select the Heat option on the screen.

  6. When prompted, select the nozzle(s) corresponding to the Bowden tube(s) that you wish to clear.

  7. Press Done to exit from the manual heating utility.

  8. While the nozzle is heating, remove Bowden tube from the extruder.
    • Plastic: Remove the thumbscrew that connects the plastic Bowden tube to the plastic extruder.
    • Fiber: Use a 2mm hex key to slightly loosen the top left socket head cap screw on the fiber extruder, then remove the fiber Bowden tube from the fiber extruder. 
      Note: Do not unscrew it all the way. It should require no more than one full turn to loosen.

  9. Once the nozzle is hot, pull the filament from the Bowden tube.
    Note: The tip of the filament that was within the print head may be hot.
  10. Once the fragment of filament has been removed, reattach the Bowden tube to the extruder.
    • Plastic: Insert the nut into the plastic extruder and tighten the thumbscrew.
    • Fiber: Insert the tube’s metal insert into the notch on the front of the fiber extruder and tighten the screw.
  11. Load new materials. For more information, please read Load Plastic and Load Fiber

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