Using an E3D Lite6 with a Bowden Configuration is a pain in the arse. I’ve had them on 2 FB2020s now (Stop-gap hot ends), and it’s been nothing but trouble. The 2 main issues I’ve found are that the PTFE Tube doesn’t make a good enough seal, even with the collet fully up, and when it does it’s most likely too close to the heater block, so it’s going to degrade quickly. The main issue I’ve found with a Lite6 in Bowden config is the pressure is too high for the tube to stay reliably sealed against the top of the nozzle. The best way I’ve found is to back the nozzle off and push the tube against the nozzle and tighten it back up so it pushes the tube and the collet up if you don’t get it right, you end up with the risk of the tube being partially in the heater block. For Bowden, I’m sticking with the v6, the Lite 6’s will stay on the Prusas, which are direct drive, so a lot less pressure. I’m sure there’s people out there using Lite6’s in Bowden config, but, it’s not for me.
I made this http://www.thingiverse.com/thing:989886 to combat the bowden tube moving around in my E3D v6 (full version). Push the bowden tube in with the heat break unscrewed slightly (only half a turn at most), put the clip under the bowden release ring, screw the heat break back up. It makes for a REALLY tight fit.
I insert the Teflon tube past the opening. Then pull it back to engage the collet. Lock the collet down with the clip then trim off the excess tubing with a sharp razor. Then I’ll screw on the heat block and nozzle.
Well my v6 heat break and heat sink came in today so, I’ve no longer got the issue. Just running the final tests before I throw some Colorfabb XT in there and run off a set of FB2020 parts…