Solved Extruder jambing - not clogging

I've have successfully printed hundreds of things, gone through probably 20 spools of PLA so far, and I've had little issues here and there, but this one has me kind of baffled as to what to try to do to correct it. I'm thinking too hot or too cool and extruder. As you can see from the attached photo of two of the jambs I've pulled out, the PLA is bunching up at the top of the extruder. The extruder fan is working, and I'm running standard feed speeds etc. I'm running the extruder at 200 degrees, but I am trying a test print right now at 195. It seems about 1 out of 3 or 4 things prints just fine. Any suggestions? Have I missed something?

My theory is that either the extruder is too hot, and the PLA is softening at the top, or the extruder isn't hot enough and the PLA is too thick and won't flow fast enough.

 

While heat creep could be causing it, are you sure the nozzle isn’t damaged/blocked in some way ?


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If he printed 20 rolls of PLA, then maybe the fan that cools the extruder heatsink fins is dirty / dusty, or is not performing well / failing....



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Or he could be playing Bob Marley “Jamming” ... but the first idea is more likely



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Thank you all for the quick replies. I do season my hot end, it is not new. The printer will sometimes print half an item before it stops, sometime less, sometimes everything, and it's printing as well as it ever has. I had one other thought... see the attached picture. The original extruder mount thing broke, for a while I was able to get it to hold the hot end, but I finally replaced it with one I printed from a file on thingiverse. Is it possible that this is slightly out of alignment and that is why it's jambing? I think I'll call customer service tomorrow and just order one, unless someone knows of an accurate file.

 

This one is tight, but could be misaligned I suppose. It was hard to match it to the old one as it had broken in 3 pieces, and one of the pieces fell into the abyss that seem to swallow all my screws. It claimed to be an original replacement part, but it was too thick and I did have to sand almost an eighth of an inch off to get it in there.

 

Hmmm, well, I guess that's my first option, to buy one from Robo. Of course the printer is running fine right now, I cut the temp down to 190, but I won't know until I get up in the morning if it completes the job. Either way, I will get the part direct from Robo.
I am going to leave this temporarily as unresolved until I get several prints through it either at a lower temp, or with the new hot end holder.

 

I tried to order the part from Robo but they don't sell it, they directed me to a site that had the correct stl file. Fortunately for me I have friends with 3d printers who could print one for me. It's printing like a dream now!

 

For anyone who was following this, the problems all came back. It seems likely that the fan which cools the hot end was actually the culprit. I'll know for sure in a few days. It seems the top of the hot end was getting so warm that the filament was softening and jambing. At least that's my current theory.

 

Concerning micro clogs I found on Amazon little drill bits that fits up into the nozzle. Brand name is Kamo