I’ve been trying to print some things in TPU, using a fairly soft 85A TPU, and I keep having under extrusion.
I’ve already reduced speeds to max 25mm/s, and reduced retraction. My printer uses a direct drive extruder, and as far as I can tell, it’s grabbing the filament just fine. I’m printing at 240°C, using my default 0.4mm volcano CHT brass nozzle.
Great tip! I spent a long time chasing issues with TPU only to realize the spool to extruder section was the culprit. Bypassed the runout sensor and put the spool on bearings to fix the issue.