Filament gets stuck above the PTFE tube  

Eminent Member


I have a Prusa I3 MK3s and filament got stuck twice today for the same reason - as in the image.

The problem appears above the PTFE tube as in the image. What could be the problem, do you think the filament is bad or maybe something else?

Thank you.


Posted : 09/11/2019 4:57 pm
Illustrious Member

A few things can cause problems with feeding filament in the upper extruder:

  • If you are printing PLA in a hot room or enclosure, temps can get high enough to soften the filament and cause feed problems. Cool the extruder area down and improve air flow.
  • If you are doing a long print, or any print with intense retractions, it can contribute to heat. Investigate retractions and also improve air flow.
  • If you are printing flexible materials with overly-aggressive speeds, it can buckle and cause feed problems. Slow speeds way down.
  • If the bondtech gears are not aligned with the filament feed path, it can cause binding. Does filament fed by hand through the top feed without snagging?
  • Some filament is out-of-spec. Try another filament to confirm it's still an issue.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 09/11/2019 6:35 pm
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