Re: Which printable replacement head?
Ok, I figure it out. It is caused by the hot end not being assembled correctly.
This can happen if you take apart your hot end to try and clean it, or buy a self-assembly j-head.
If all the parts in the hot end are not screwed up enough so that they all touch, you will get a gap that will fill with melted filament and block.
The image below shows the filament removed from a j-head after I didn't assemble it correctly and it blocked. The wider filament on the left would have been in the PTFE sleeve. Then you see the largest diameter part of filament, this is where the gap between the PTFE sleeve and nozzle was and is the blockage.
The second image shows the same problem, but with the standard solidoodle hot end.
I've reassembled the J-head and so far so good with extruding filament only. About to a test print now...
