Pellet Extruder with Auger + Moineau screws

v0.8, Monday 22 August 2016.
UPDATE, 31 Oct 2016: a new improved version has been published as: http://www.thingiverse.com/thing:1861347

This is a *very first attempt* to design a (full-parametric, customizable) prototype extruder for plastic pellets that can work for common 3D printers. The real extruder should be obviously printed out of metal (stainless steel, probably) at a smaller scale and many parts will have to be added/improved (for example: the head should be able to accept "standa