Direct Drive Extruder for Mendelmax 2

A direct drive extruder i'm working on. Designed it for my selfsourced Mendelmax printers. Should be printed in ABS.
Video of how it works :
http://youtu.be/lGPvlqaNrRw
Assembly instrucions (german) can be found here:
queckland.de/queckprint3d/Uploads/Anleitung/quextruder.pdf
It is still a wip, it works but the design has to be cleaned up. Soon™