My other printer

[jdurand]

I'm still printing those structured water devices on my Afinia printer and other than then "natural" filament having a few bad spools it's been plugging along with no problems. Well, today two prints aborted with a jammed nozzle. I ran a wire through it and extruded some more and looked at in under a microscope. OMG! WTF, there's assorted crap in there! I extracted the filament and cut off the end to look at under the 'scope. Crap on the very end but nothing up higher. ?? Had the thought to take the extruder apart, there was a ball of black fuzz in there going around with the drive gear. I presume bits were getting stuck to the filament and fed down to the nozzle. Cleaned it all out and starting a new print now. Hadn't expected to find dust balls inside the extruder.

I do run the filament through a piece of foam rubber, some spools seem extra dirty but this one seemed to be running clean. No idea when that fuzz got in there, I've run dozens of spools through that machine since the last time it was apart. Even the build-tak surface is running around 250 uses and still going strong.

Almost forgot: sharks with frickin lazors

[Nylocke]

Do you have the "top" of your dust filter labeled? Maybe you flipped it on accident and dust from previous prints came out the top (assuming its a standalone item).

[JFettig]

probably crusties building up inside the nozzle - burnt stagnant filament breaking free. I had something similar happen once - all I could figure it to be.

[jdurand]

I use a new piece of foam each time so I don't do that.

I was thinking it was a buildup but I ran a piece of music wire through which being cold pulls out a blob of plastic and it wasn't covered in gunk. I'm guessing the fuzz built up over the last couple of dozen kg of filament since the nozzle was last cleaned and just got to the point of having bigger chunks get dragged into the nozzle. The overnight print ran fine and I started another one 4-1/2 hours ago and it's doing fine.