The Bits from Bytes Polymer Extruder
The STL files for this are available from the [sourceforge.net/p/reprap/code/HEAD/tree/trunk/darwin/mechanics/bits-from-bytes-designs/STLs-for-reprapping/ RepRap Subversion repository here], so you can print them in a RepRap machine. The [sourceforge.net/p/reprap/code/HEAD/tree/trunk/darwin/mechanics/bits-from-bytes-designs/DXFs-for-laser-cutter/ lasercutter DXF files are here]. In a lasercutter cut them from acrylic. In a RepRap machine print them in PLA or ABS (note - we haven't tried this yet; it should work fine, but watch the blog for details).
The PDF file [[File:BitsfromBytesPolymerExtruder-ExtruderAssembly.pdf gives complete diagrammatic instructions on how to assemble the extruder.|thumb]]
In addition, there's a [sourceforge.net/p/reprap/code/HEAD/tree/trunk/darwin/mechanics/bits-from-bytes-designs/DXFs-for-laser-cutter/ video tutorial on putting together the heater barrel] at the Bits from Bytes site.
-- Main.AdrianBowyer - 28 Jul 2008