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Debugging what looks like clogging.  

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Debugging what looks like clogging.


after re-assembly of my Original Prusa Mini+, I get results that indicate some sort of clogging to me.

Doing a first layer calibration print I get a repeated pattern of: correct extrusion amount - under extrusion - over extrusion.
It is also reflected in a few other test prints I did. In my opinion, it is not linked to retractions.
I tested Das Filament PLA (generic Settings in Prusa Slicer) and Prusament PETG (Prusament PETG Settings in the Slicer).

What I tested thus far:
- The Extruder seems to be pulling in the Filament in a constant manner. Tested by feeling how the Filament gets pulled in the PTFE Tube while printing.
- Nozzle is not Clogged. (Tested 3 new 0.4mm Copper nozzles.)
- There is no Filament building up in between Nozzle and Heatbreak.
- There is no FIlament building up in between Heatbreak and PTFE Tube.


My logical conclusion would be an issue Extruder.

Is there any test you would recommend me to do?
Do you have points I might be missing?


This topic was modified 4 months ago by NielsW
Posted : 31/05/2022 8:56 am
Famed Member
RE: Debugging what looks like clogging.

Good thing is there are only so many places blockage can occur. You've tried several nozzles, so a partial clog is unlikely. Assuming your diagnosis of no blockage in the filament path between nozzle and extruder is correct, yes, this point to the extruder. It could also be the filament snagged somewhere around the filament spool, so I'd check that as well. If it's the extruder, I'd take it apart and examine the motor axis. The stock extruder in my hands was notorious for grinding filament if the idler screw was not absolutely properly set (I now use Bondtech extruders that don't have that issue). Could be crud accumulated in the extruder.

Posted : 31/05/2022 10:42 am
New Member
Topic starter answered:
RE: Debugging what looks like clogging.

Thanks, that's what I feared. There is actually some crude accumulated. I'll test the Bondtech IFS upgrade.

Posted : 01/06/2022 12:23 pm