Flexible filament (TPU) jamming
TPU bunches up inside the extruder, wraps around the gears or won't feed at all.
Also described as tpu jam, tpu not feeding, flexible filament problems, tpu tangled in extruder, tpu buckling
Try these in order
Most likely and quickest to check first. Change one thing at a time so you know what fixed it.
Printing too fast
- Slow right down: 15 to 40 mm/s, and lower still for soft grades below 95A.
Gaps in the filament path
Soft filament buckles into any gap between the drive gears and the hot end.
- Use a direct drive extruder with a constrained path if you can.
- Loosen the extruder tension slightly so it doesn't squash the filament.
Retraction
- Turn retraction down to 0.5 to 1 mm, or off.