SmartAlu geared extruder V. 0.99b

I'm very happy with my homemade geared extruder for the SmartrapCore, so I thought I should adapt it for the SmartAlu. This one is designed to be suspended under one of the Y-axis bars, and it's inverted so that the NEMA17 motor is on the inside.

Update (may 3rd 2017) : changed the front and back body parts design, for easier installation on the alu structure.

Update (may 28th 2017) : added a small piece that keeps the bowden from rubbing against the GT2 belt.