Filament Not Loading

Updated 3 months ago ​by Tomáš Chvalina

When your filament is not being properly loaded. Yet it is still able to pull the filament inside. It is usually a simple hardware problem. Which we will fix in this article.

For the start, let's go over the checklist for a proper load of a new filament.

Ideal preparation checklist:

  1. Cut the tip of the filament at a 45-degree angle 


  2. Filament goes straight around the pulley into the PTFE tube - !If it is bent slightly it may go around, especially flexible filaments sometimes tricky to align perfectly!
  3. Make sure that there are as little deformations as possible of the filament which is being loaded in.
Make sure that you are using proper nozzle temperatures. 

Mechanical problems:

  1. Loose pulley: ensure that the set screw of the extruder drive gear is secured against the flat side of the extruder motor shaft.
  2. Gummed up teeth: the extruder gear has teeth which bite into the filament, ensure that the teeth are clean and clear of any plastic.
  3. Extruder gear misalignment: the filament has to travel in a very specific path, any sort of deviation will create friction and cause the extruder to either misdirect the filament or be unable to feed it properly. Visually check to see that the groove of the extruder gear passes directly inline with the top of the hot end PTFE tubing.
  4. Loosen / Over-tighten extruder strings: extruder strings are putting pressure on the filament which is being loaded. Make sure that they are not too loosen or tighten. 
Would none of the above ease your problem. Please visit Clogged nozzle - MK2/MK3. There is a chance that you are dealing with a clogged nozzle. Rather than Filament loading problems.

Do not hesitate to contact us at info@prusa3d.com if you would have any following questions.


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