How to Clear and Prevent Filament Jamming on Your 3D Printer

More or less, we’re likely to encounter filament jamming while using a 3D printer. How to clear and prevent filament jamming surely becomes a question for most 3D printer users. And the best is to understand the structure of a 3D printer first.

Generally, an extruder of a 3D printer is composed by a cold end (which is also called extruder by a lot of users) and a hot end which includes melt zone and a nozzle. 

3D filament is pulled by stepper motor driven gear and bearing assembly on the cold end (extruder) into the hot end.

And 3D filament melts and extrudes at the hot end and filament commonly jams at this part.



Causes and Solutions for 3D Filament Jamming

When filament jams on your 3D printer, it’s mainly caused by below situations. And we also enclose solutions for jammed 3D printer in this paragraph. 

  1. Heat Creep

Heat creep commonly happens when the hot end heat sink works improperly and heat creeps into the heat sink part before the melt zone. It causes half melted filament stacking inside heat sink and filament jamming happens.


Stop printing when filament jams and clear the extruder. Check if the fan works properly or heat sinks are installed well. If not, fix the problem for a better heat dissipation.

  1. Low Temperature Hot End

Low temperature hot end results in insufficient melting of filament and jamming happens too.


Set print temperature according to recommended value for your filament. Normally, it’s better to set around 200℃ print temperature for PLA filament and 245℃ for ABS filament. If it still won’t work, rise up the print temperature until it begin to extrude. Be aware of that, do not set a print temperature higher than that of the hot end can bear. Of course, before you reset print temperature, please clear jammed filament first.

  1. Too close distance between the nozzle and print bed

If the nozzle is too close to the print bed, certainly filament would be blocked inside while extruding.


Recalibrate and level the print bed again for an appropriate distance between the nozzle and the print bed. Also refer to this link print bed leveling.

  1. Inconsistent Filament Diameters

Inconsistent filament diameters lead to incoherent filament pull-in and cause an instable filament melting. And finally, the extruder jams.


Check diameters of your filament in different positions with a caliper. If measured out diameters vary great, please consider a new filament brand for your daily 3D printing.

  1. Dust particles on filament

When dust particles cover the filament you’re using, they tend to burn when get inside the melt zone and jam the extruder.


Use cold pulling method to clear jammed filament. Below are detailed instructions to do it step by step.


Cold pulling out of jammed filament in 3 steps

Most 3D printer users are likely to use a heat gun to clear jammed filament and some others even use fire or chemicals to do that. And we recommend you use a much safer way to clear extruder by cold pulling. You need only three steps to go for a clean extruder. 

To do a cold pulling, you should set print temperature to a glass transition degree first. The jammed filament will turn into a more friendly mixture in half solid and liquefied status for easy pulling out by hand. The cold pulling method is quite suitable for nylon, ABS and PLA materials.

Of course, before you go into cold pulling, remove filament inside the Teflon pipe and pull it off from the hot end first.

The first step is to heat up the nozzle to print temperature and manually push a 10cm long filament into the hot end. And when pushing in, please keep the filament in straight. If the nozzle doesn’t extrude, use a thin wire and clear the nozzle. 

The second step is when filament begins to extrude, lower print temperature to 120℃ for ABS, 90℃ for PAL, or 100-140℃ for nylon for an ideal status of filament extruding. And make sure dripping filament is cut off before you do the next.

Third, pull out jammed filament when it extrudes slower and slower. If the filament still extrudes fast, lower printing temperature; if filament can’t be pulled out, rise print temperature a little higher until it works.

The above are some very useful solutions for filament clogging that we recommend to Anet 3D printer users. Filament jamming might be caused by various reasons. Therefore, please refer to above instructions and find out the actual cause to clear and prevent your 3D printer from filament jamming.


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