I have a UMO with heated bed and hot end upgrades (does that make it a UMO+?). It has printed well for years but is now jamming and stopping extruding. I have replaced everything past the bowden tube, including a PTFE coupler and still having the same problem. The first layer is usually perfect, but at some point after that it stops extruding. I never get a finished print. I'm printing ABS at 242 and bed temp of 111. I've tried Atomic pulls but the filament always breaks in the coupler. I've even tried putting a cooling fan on the PTFE coupler. Every time it jams I have to take the whole hot end apart, soak in acetone and gradually remove all the ABS, which takes days. Any suggestions? I've getting desperate!
