This week was spent outfitting the printer with the new extruder. The Herringbone extruder was quite a finicky device to build in the end. It's considerably more difficult to mount than the other two extruders I built, but the results have been well worth it by way of better quality prints:
(And yes, it works!)
I also finished the heat bed and mounted that to the Y axis:
Now that I have a heat-bed I've had another attempt at printing ABS plastic which is supposed to be stronger than PLA. Unfortunately results haven't been promising so far. In the following photo the first piece is one I printed a few months ago in PLA, the next two are versions I printed this week in PLA (the shiny side was in contact with the heatbed glass) and the last piece was one I also printed this week in ABS:
I haven't calibrated the RepRap for ABS yet but even so it seems to extrude "blobby", has more trouble sticking to the bed and just doesn't produce good results. Of more concern is the fact that it jammed my extruder....again! ABS is normally quite soft but when it's heated and cools down it seems to go very hard. This seems to have happened in the PTFE liner in my heater nozzle, and since the drive bolt couldn't push the filement through it proceeded to tear it to shreds:
For the time being I think I'll stick to PLA and maybe give ABS another go with my next machine. My next task is to finish off calibration and then start work on printing the parts for a whole new RepRap. Exactly what I do with those parts, I haven't yet decided...