Printruder II

After the success of my first printable extruder design (the Printruder, see http://www.thingiverse.com/thing:958 ), I wondered, if there would be an even simpler and better design for a Printruder.

This is what I came up with.

Please note, that there are two flavors of the main part ("Motor Block"):

Motorblock_v7_TimerBeltPulley.stlThis design is for use with the standard timer belt pulley, which comes with the MakerBot Extruder MK3/MK4.
Motorblock_v7_WormGearPulley.stlThis design is