Folks, I had my new extruder for a week or so, and managed to get filament stuck in the cold end. It was woodfill and the print failed (failed to extrude). When I tried to move the filament in either direction, It was frozen. Talking to support, they suggested jamming the cooling fan so that the transition would heat up a bit, loosening the filament and allowing it to move. That didn’t work in my case.
It was also suggested that in general, when removing filament in a controlled situation, to extrude a couple of cm of material before rolling it out.
Honestly, I’ve had my Taz for a few years now, and I never got into a situation, other than the nozzle getting gummed up, where I couldn’t resolve a jam. This new unit is a bear.
I feel your pain. Never ever had a single jam with the Hexagon… But I have had to completely disassemble the Aerostruder twice.
In my case, the jams occurred when removing filament. Once with Nylon, once with ABS. The slightly “swelled” portion of filament from the hot end got stuck in the plastic “filament guide tube” that sits between the heat break and hob. Trying to pull it through with more force just wedged it in tighter – to the point I couldn’t move it either direction.
I will confirm what Lulzbot support told you does help. When swapping filament, I now (1) Heat to full extrusion temp, (2) Slowly extrude 5-10mm, then immediately (3) Slowly and steadily retract until the filament comes up through the hob. That seems to stretch / taper the filament as it comes out of the hot end, allowing it to freely move through the heat break and that guide tube. If it stops moving at any point – stop retracting, send it back down and extrude a bit more, then try the slow retraction again. I haven’t had another jam since using that procedure (knock on wood).
I’ve also had a problem swapping filament. But I found that I can reach in with a pair of cutters to snip off the blob, and then pull the blob out separately without passing through the plastic guide hole. No need to disassemble…
Depends on where the blob is catching. Sounds like for you it was catching in the idler – I’ve had that happen as well, and there is a little access there. But if it gets caught coming up through the guide tube (which is between the hob and the heat break), there is absolutely no access to that without disassembly.
