xtrhdr a geared nema23 extruder for a cupcake

This is an extruder for all the cupcake owners who have the wish for a stepper extruder and have some spare cheap nema 23 steppers.
Based upon the lovely extruder from Jag; Yet another extruder filament drive thing:7113.
It uses a makerbot MK5/MK6 filament drive gear, an extra stepperdriverboard, three 606 bearings and a variety of nuts 'n bolts.

The goal was to use an old low torque stepper, the makerbot MK3 hotend (in the process replaced by something better..) and a lot of plastic. (aka