Paste Extruder Stepper Motor Printing Head

This is a screw driven peristaltic Paste Extruder. It is still experimental, so before you decide to build it please check the following videos to see it in action:

- extruding polymer blend (hair gel):
http://www.youtube.com/watch?v=1XWYLSRCcq8

- extruding viscous chocolate glazing:
http://www.youtube.com/watch?v=qIFkw5RNXqQ

- extruding polymer blend at 16mm/sec, 0.5 mm nozzle, 250 micron layer:
http://www.youtube.com/watch?v=axAP0btw4Lk

Some pictures of the printing head: https://picasaweb.google.com/ioan.festeu/ReprapPasteExtruder?authuser=0&authkey=Gv1sRgCJnau7ew38qs7AE&feat=directlink
You will find a 3D pdf file attached so you can easily inspect the pump.

Also I have attached a dxf file for the laser cutted acrylic mounting plate for Rapman 3D printers. Sorry... for Makerbots and Mendels you will have to find your solution :)

CAD drawing picture shows in yellow the printable parts. The rest of parts are stock M6 threaded rods, nuts and washers and two inex