Simple, strong, Bowden Extruder

Printed solid in ABS, in an enclosure. Some support needed.

Required hardware:

* Nema17
* Mk7 hobbed extruder gear
* Grooved 608 bearing
* M5x15mm bolt
* M5 nut
* 2 of M5 washers
* Extruder Spring
* M5x25mm bolt
* 2 of M5 Slim Pre-Assembly T Nut
* M5 Bowden push fit coupling
* 2 of M5x12+mm bolts for fixing to 2020 extrusion
* 2 of M5 washers
* 2 of M5 T-nuts
* 2 of M3x12+mm bolts for fixing motor
* M3x20mm bolt