Ender 3 pro standard hot-end.

[MattF]

Have you seen the mod I made to my Ender hotend? Just a little 13mm length of teflon which stops the Bowden tube from getting loose?

Linky: #16

Cheers. I'll have a watch of that later.

 

[MattF]

Only leak I had was my own fault. I didn't tighten the new nozzle properly and the filament oozed through the threads, insulating the nozzle from the hot-end and causing a blockage. Had to remove the hot end, pull the heat break tube and nozzle out, run a M6 tap through the hot end and wire wheel the nozzle and heat break to clean the threads for good thermal contact then re-install them (properly tightened this time). It all worked great afterwards but I won't do that again...

I think it's done it to me twice, now. First was with the original nozzle in, & later down the line with a replacement I'd fitted. How tight is tight enough, for the nozzles?

 

[Pete.]

I think it's done it to me twice, now. First was with the original nozzle in, & later down the line with a replacement I'd fitted. How tight is tight enough, for the nozzles?

Nipped up with a spanner I'd say. If they are already plastic-coated from a previous leak I'd take measures to get the plastic off, or at least get the hot end hot then nip it up so it squeezes the film of filament out of the threads.

 

[m_c]

A common trick is to heat the hotend hotter than you'd normally run it, then nip it up.

 

[Screwdriver]

The fundamental issue is that either you use a tight teflon tube which resists heat but is a bit too tight OR use the regular Capricorn tube which is slipperier but can melt.

Even a slight softening or melting allows the bottom join where the hot plastic goes into the heat break to wiggle loose. The filament goes in and out a lot during printing so unless the join is perfectly connected, eventually a bit of molten plastic can escape. Soon as it starts to get out, the effect is amplified until the hot end becomes a solid brick of plastic.

So the mod uses a bit of teflon which is independently clamped hard down to the heat break, then the capricorn tube is held (loosely!) in place well away from the heat. Best of both worlds, never had a problem since.

 

[Mart63]

All metal heat break is cheap enough. You have to reduce your retraction setting though.

 

[MattF]

The fitting instructions, (or rather lack of), which come with that hotend are shocking.