Quote Originally Posted by Geoff View Post
Sorry to be a party pooper, but I have never had my $12 nozzles leak from internal junctions - ever. There is a brass nozzle attached to what appears to be a steel cylinder which heats up and pre-melts the filament before it's pushed into the hot end - there is nowhere for it to leak. I've been through close to 50kg of filament.

I am still having trouble understanding the short 'melt-zone'

can you explain that in a bit more detail please?
Yeah, some people experience leaks, some people don't. It really depends on the hot end and the assembly.

As for the short "melt-zone", basically I am referring to the length of the heated portion of the hot end. A short "melt-zone" means a short heated portion, which translates to a smaller volume of molten filament in the hot end, which in turn results in less "ooze" from the nozzle. 'Ooze' is caused by gravity acting on the liquid molten filament pulling it down through the nozzle (you can test this by turning your printer upside down! No more ooze... but it is awkward having your printer upside down). By decreasing the volume of molten filament in the hot end, you are decreasing the pressure that gravity is exerting on the molten filament and therefore less plastic oozes out of the nozzle tip.

Hence, shorter "melt-zone" = less "ooze" ---------- longer "melt-zone" = more "ooze"

Eric