@Garfield said in E3D heatbreak inner diameter question:
It's my experience that jams are often caused by cheaper filaments or over enthusiastic retraction - some of the defaults I found for firmware retraction when setting up my Duet (based on initial codes produced by the online tool) were excessive in the extreme (10mm) more suited to a bowden than a direct extruder - even then it's a lot.
By retracting too far you pull molten plastic back into the heat break where it has no place being, it cools and bam ....
Agreed. I just checked my config.g and indeed it's set to 2mm... Max practical retraction on my HEVO is 1.5mm or so due to high PA value. Nice pointer! I forgot to uncomment a line in the config.g as I was testing something the other week.