I had gotten about 20-30 hours out of the last modification and I than I had a extrusion failure.
Initially, I thought I thought, the failure was the pla seizing on the nut holding the hollowed out M6 threaded rod and the PTFE tube.
Later it became apparent the my nozzle was partially clogged. In the process of removing the nozzle I snapped the threaded rod. Initially, I made a quick fixture when I drilled out the threaded rod. Basically a piece of 7/8 ? bar with a tapped hole in it. I believe the drill walked when I but the hole in and It looks like that didn’t help the cause. I broke the other one when I was drilling out the hole.
Anyway…. I’m not going to spend 8 bucks on a piece of machined threaded rod that I need to mod anyway… Soooooo… I guess I’m going to take the time to make a nicer fixture by boring out rod so it’s concentric, and doing a small production run of these and to have the PTFE liner.
At some point, I think I’m going to wind up making my own extruder… While my modded qu-bd is performing better now, I think it would be easier to have the features I want by starting from scratch.