Clearing a Plastic Material Jam

 Note that the plastic extruder and print head are factory-calibrated; do NOT adjust or disassemble in any way unless specifically instructed to do so by Markforged Support. Warranty claims for assemblies that have been adjusted, disassembled, or modified may not be honored.


When troubleshooting a plastic material jam, the first step is to determine whether the failure is in the plastic extruder or the nozzle.

Determine the source of the jam

  1. Heat the nozzle using the Temperature Control utility (Utilities > Manual Control > Temperature Control).
  2. Once the nozzle has reached temperature, unscrew the thumbscrew that secures the plastic Bowden tube to the print head.
  3. Carefully remove the tube from the print head. The tip of the plastic tube will be hot. Be sure to not let it contact your skin.

Depending on the results of the steps above, the failure is likely caused by one of the two following reasons:

  • If plastic is able to be freely extruded from the end of the plastic Bowden tube, the jam is likely in your nozzle.
  • If the extruder motor skips or does not push plastic freely, the jam is likely in your extruder.


Remedy the jam

  • If the jam is in your nozzle, replace the nozzle and reload materials.
  • If the jam is in your extruder, remove the inlet Bowden tube and then pull the plastic out of the extruder.

When you are ready to print again, reassemble all components and reload print material. Clip the end of the plastic filament at a 45-degree angle before inserting it into the print head.