Extruder question (wade type)

I am thinking about my build. I have seen elsewhere that some RepRaps have used a feeder seperate to the actual extruder connected by an hpfe tube. This would suit my micro-mendel version nicely. I am planning to use the same NMEA17 stepper as the axis.

Can anyone verify that this works well? Where can I get some hpfe tubing??? (I am in Australia so shipping costs can be an issue)

HPFE PTFE is a sort of teflon isn't it? YES

Edited 2 time(s). Last edit at 10/03/2010 09:55PM by cluso99.

HPFE is a typo for PTFE, which is teflon. Googling the phrase 'bowden extruder' should turn up some more information.

The biggest (only?) downside I have heard of is that the PTFE tube will stretch, which causes some lag between extrusion starts and stops due to the build up and release of that tensile force. I thought maybe some steel braided hose with a PTFE liner might reduce the amount of elongation and make the effect less significant, but I have not had a chance to try it yet. Shorter tubes will have less elongation, so you can also minimize the problem by using the shortest tube possible.

Here is a thingiverse page that says what tube to use: http://www.thingiverse.com/thing:3775
They recommend getting it from here: http://www.adtech.co.uk/

Here is what I got: http://www.summitracing.com/parts/ZEX-NS6612/
It comes with fittings attached from the factory that should make a more reliable connector, but I notice that there is a slight snag somewhere on the fitting as plastic passes through it. As I haven't tried it yet, I can't tell if this snag could cause a significant problem. It doesn't seem to make a significant difference on the pull force, but if it creates a lot of dust, that might be a problem.

Edited 1 time(s). Last edit at 10/03/2010 07:51PM by dazed.dnc.