Plastic Bowden Tube Replacement


  • 10mm open-ended wrench (optional)


Note that the images in this article feature the A3648 plastic extruder; for more information on different versions of the plastic extruder, see the A1095 and A3648 Plastic Extruders support article.

Your printer's plastic Bowden tube wears naturally over time due to the abrasiveness of the print material; it will wear fastest where the tube bends sharply (see images below).


Replacing the tube is a relatively simple maintenance operation, taking roughly 10 minutes to finish.Below is a diagram of the plastic Bowden tube assembly. Note that the two ends of the tube have different hardware installed.


Remove Plastic Bowden Tube

  1. Begin by removing any plastic filament from the Bowden tube using the Unload Plastic utility. Ensure that the Bowden tube is completely clear of print material.
  2. Unscrew the Bowden tube retaining screw from the print head. Withdraw the screw and tube, along with the ferrule. (Note: If you are unable to loosen the thumbscrew by hand, use a pair of pliers and take care to avoid stripping the thumbscrew knurls.)

  3. Detach the extruder end of the Bowden tube by unscrewing the second retaining screw from the extruder's brass adapter. The M4 standoff (shown in step 4) is inside the extruder and will pull out along with the Bowden tube.
    Note: If you have trouble removing the Bowden tube retaining screw from the adapter, use a 10mm wrench to hold the adapter in place.

  4. Unscrew the M4 standoff screw from the extruder end of the Bowden tube. Do not pull the standoff screw directly off the tube! It is threaded onto the plastic tube and must be unscrewed rather than pulled straight off. Note the threads in the image below:

  5. With the M4 standoff removed, slide the plastic tube retaining screw off of this end.

  6. Remove the old Bowden tube from the flexible black energy chain. Grasp the Bowden tube by the print head end and pull forward until the entire tube is free of the energy chain. The image below shows the extruder, the disconnected tube, and the direction of movement:


Install New Plastic Bowden Tube

  1. Begin by removing the M4 standoff and the retaining screw from the extruder side of the replacement Bowden tube.

  2. Manually slide the print head to the back right corner of the printer. This straightens the energy chain, making it easier to snake the tube through.
  3. Grasp the now-exposed extruder end of the Bowden tube and insert it into the print head end of the flexible black energy chain, then snake it all the way through to the extruder.

  4. Once the Bowden tube passes all the way through the energy chain, install the following hardware:
    1. Slide the Bowden tube retaining bolt on first, with the threads facing the extruder.
    2. Screw the M4 standoff back onto the threaded plastic of the Bowden tube.
  5. With the extruder end hardware reinstalled, insert the M4 standoff into the brass fitting of the extruder, then screw the Bowden tube retaining screw into this brass fitting.

  6. At the print head end of the Bowden tube, carefully insert the ferrule into the appropriate opening. Now screw the print head end tube retaining screw partway into the print head. Unscrew it, then finger-tighten the tube retaining screw into the print head.

  7. You can now load material and resume printing.