FlyStrudy - a rubber band flying extruder

This is my attempt to create a flying extruder for delta printers. I'm sorry I've no pictures to show yet, but will update soon.
The idea is to use rubber bands instead of a spring. this way you can regulate the force applied to the filament.

Print everything without supports.

Assembly stuff:
1 x M3x6 (or similar)
3 x M3x25 (maybe you'll need washers)
1 x M5x20 + nut and washer.
1 x flat bearing 16x5x5.

Edit 31/01/2017:
I just fixed two files which resulted to be non-manifold.