Thermal Barrier Retainer for Pinchwheel extruder

So I noticed that gluing in the thermal barrier into the base of the pinchwheel extruder seemed a bit prone to failure. Also people seem to have problems with the thermal barrier bulging over time. So I drew up and printed out on the FDM Titan this part. It is made from polycarb and can be bolted on with some M5 90mm caps through the block, base, and retainer. Also it completely encapsulates the PTFE to keep the bulge at bay.

You can download the STL, and Solidworks file at Thingiverse.

[www.thingiverse.com]

Here are some pics











The barrier here is from Makerbot so is the barrel, also an FDM Quantum tip will thread right on the Makerbot barrel. I'm going to be using the FDM tips because I have a handful from our old Quantum at work.

Cool.

Curlrup, could you tack that up on the wiki as well, say at
[objects.reprap.org] Barrier Retainer
?

polycarbonate's glass transition is at 150 celsius and it melts at 267. looks like its close enough to the barrel to cop the full heat of it

Triffid_Hunter Wrote:
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> polycarbonate's glass transition is at 150 celsius
> and it melts at 267. looks like its close enough
> to the barrel to cop the full heat of it


Yeah I am concerned about that as well. I might make a mold and cast it out of a hightemp urethane, or the new FDM we got at work will be able to run ALTEM which would work very well for this.

You might design it to have a side slot that you insert a metal retaining washer in like on the cupcake extruder design or simply have a flange for the bolts that the retaining washer anchors to.

freds Wrote:
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> You might design it to have a side slot that you
> insert a metal retaining washer in like on the
> cupcake extruder design or simply have a flange
> for the bolts that the retaining washer anchors
> to.


That's the thing this is to eliminate the washer and control barrier bulge. This does the retaining the washer does. I think the Polycarb is going to run into some heat issues.