A recent print failed, which is fairly rare for my Mendel90. Unfortunately, it failed in a new (for me) way. For some reason, which probably involves one of my sons, the print bed was badly out of level. Of course, I didn't know this when I started the print. It didn't look quite right when printing perimeters, but still looked like it would work. When I came back later I found that the hobbed bolt had clogged up before finishing the first layer. It looks like the nozzle was basically blocked and the back-pressure built until the hobbed bolt tore the filament to shreds. A bit of inspection has confirmed that the hobbed bolt chewed into the filament.
Trying to remove the filament (85C, M302, retract 100mm with help from me to get it started), I can't get it to budge. I've tried hotter temperatures with no luck, but am getting nervous. I think that the filament melted well up the hot end and is unwilling to let go.
Unfortunately, with the Mendel90 version I have, I can't remove the hot-end unless it is free of filament. But if it were free of filament, all would be well.
Any suggestions? I'm thinking I might be able to get something sharp between the top of the hot end and the part that holds it. If I can cut through the filament, I can remove the hot end. But I'd rather just soften the filament to the point that I can pull it free.
