Going back a ways there was a discussion about the two hot ends and some of the info from the hex owners was that the fulamant path was 1.8mm dia compared to 2mm like every other hot end out there. 1.8 is way too tight and will be prone to jams. I have 4 e3dv6 and run them nostop the past year and a half. I never have a jamming problem with them. The ptfe liner makes a big difference.