I broke my extruder!
I have used my extruder with CAPA before and it has been reasonably reliable, though I was never able to get any filament (I just rolled some bits). I gave up on trying to get any and so I recently purchased some ABS.
I put the ABS into the extruder, heated it up, and ran the last of the CAPA out. I turned the temperature up on the extruder, but was unable to get past 159 degrees. Eventually I decided that the temperature was not going to get any higher so I tried to run the ABS through anyway.
In the past the motor has stalled quite easily at low speeds when the extruder is not hot enough, but this time it didn't stall and instead pushed the heater barrel out of the PTFE rod. Presumably this is because I have never had the extruder this hot before.
I ordered some PTFE rod, some brass bolts, nichrome, thermistors, thicker cable (for connecting heater to board), drill bits and an M6 tap. This should be enough to make a few experimental barrels, although I'm not yet sure how I'm going to do this without a proper pillar drill or lathe.