The Prusa CORE One, CORE One L, and the Original Prusa XL, MK4/S, MK3.9/S are equipped with a loadcell. Thanks to this component, starting from firmware 6.0.0, the printer can detect whether the filament is stuck and not moving, for example when the nozzle is clogged.
If this is detected, the print pauses and the printer shows the message: "Stuck filament detected. The filament seems to be stuck. Please unload it from the extruder and load it again."
Once the unload button is pressed, the printer unloads the filament. After this, it prompts filament loading and resumes the print.
Repeated detections
Loadcell troubleshooting
In case of multiple, repeated stuck filament detections in rapid succession, troubleshoot the loadcell and the components around it, using the steps in the dedicated loadcell troubleshooting article.
Temperature and speed settings
If loadcell troubleshooting does not improve the multiple and repeated detection, consider slight changes to temperature and slight reductions in the movements and extrusion movements. Those can be set individually through PrusaSlicer, or in a single print speed setting, mid-print, using the Tune menu.
Deactivating the detection
It is possible to deactivate the stuck filament detection in LCD Menu -> Settings. Deactivating the detection comes with an increased risk of nozzle clogging.
34 comments
Well in my case it did, but I did do two things at once. Apparently the tension on the idler lever is pretty crucial, it actually mentions in the instructions for the kit in BIG BOLD LETTERS, STOP TIGHTENING AS SOON AS THE SCREW TIPS REACH THE FRONT FACE OF THE IDLER NUT..
I also ran the gearbox alignment step and I have a feeling that this was the actual issue because I had tried just about every possible tension scenario that I could think of.
As a side note the teeth on my extruder gear (the ones that grip the filament) have a pretty clear wear pattern, I assume from a couple spools of Fiberon PET-CF.
My printer had this problem so often that I couldnt get through an entire print without having to deal with it. Going on about a month now of several hours worth of printing and haven't had anymore issues.
I also installed the latest firmware and then downgraded back one version. That didn't help either.