Pretty sure I’m having heat creep up the Bowden tube, as it’s getting jammed a few cm back from the hot end and then can’t push the filament any more. When I get it out there’s a little molten bulb at the filament.
In this fail, I think it jammed as usual and the extruder found a way to keep going.
I tried turning down the hot end from 215 to 200 and it’s still failing. My cooling fan is running at 100%.
This is the third time I’ve had this print fail at about this layer, around 1 hour into what will be a 26 hour print.
Any ideas?
Well, if you found the jam inside the bowden tube, there’s no reason to keep second-guessing, it’s jammed.
If it always happen at the same point, I’d look at what the printer does differently there. For example, I know that if I set the cooling fan on my printer to more than 10%, it almost immediately jams (due to a design problem). But since it’s all the way into the tube, I’d suspect some absurdly large retraction.
Or, maybe, look for another heat source near the failure point. It doesn’t take a lot to bulge PLA, any electronics touching it may be enough.
(But just to add, yeah, jamming either looks like that or the extruder eats up the filament and loses contact. The better designed your extruder is, the more likely that it will look like that.)