extruder with gear for Ultimaker

This is a simple extruder with gear customised for Ultimaker.
It was trouble to use this with reprap ultimaker, but I fix it =)
Add minor changes for usability.

Small gt2 pulley could be 16 or 20 teeth. I used 100 teeth 200mm gt2 belt, model number 200-2GT-6
Bearings:
2x625zz
1x608