We’ve had an abundance of print failures since upgrading to Cura 3.6.13 and we’ve noticed that it has got to be the filament extraction protocol. If, when the print is just starting, we quickly snap open the filament clasp and push the filament down until it stops, all prints work as expected. If we don’t, filament just sputters and doesn’t feed properly.
We suspect that the initial pre-wipe GCODE is over-retracting. Here’s what we see in a typical gcode file, pre-wipe (note that we have a dual extruder):
G1 E-15 F100 ; suck up XXmm of filament
T1 ; switch extruders
M82 ; set extruder to absolute mode
G92 E0 ; set E to 0
G1 E-15 F100 ; suck up filament
So TWICE we push filament back OUT of the extruder for 100. Twice. This seems excessive, and while I can manually edit the gcode it seems like this should at LEAST be an option that I can turn off somewhere…