Although I’ve taken pains to get the extrusion amount calibrated, I have had many problems with print quality. There is a tendency to get “globs” of plastic that either get picked up by the nozzle, or they harden and cause a collision, which can cause big problems. I had heard rumours that the Makerfarm nozzle I use is different from most J-head hot ends. I began looking around, and found that most J-heads have a much smaller protrusion on the end of the nozzle. Furthermore, the subsequent revisions have no protrusion (or nipple).
I decided to modify mine and see what happens.
Will this improve prints? Stay tuned. Maybe I’ll be buying a new hot end.