Compact Bowden Extruder, direct drive 1.75mm, with bearing bloc

Last evolution of this extruder here : http://www.thingiverse.com/thing:669459

This is a remix of "Compact Bowden Extruder, direct drive 1.75mm" from schlotzz.
I added a 625ZZ bearing to counter the efforts of the idler on the shaft of nema17.
I also slightly modified the shape of the filament hole to facilitate insertion.
The idler have been slightly modified too, to adjust the 608ZZ bearing position.
Rounded edges.
Major improvment is comming soon with auto load filament due to