Bowden Extruder Flex-Filament Adapter

This is an adapter for optimal flexible filament drive of bowden extruder. Mounted on the Extruder it bridges the gab which is too big if you are printing with flexible filaments. I'm using a flying/hoovering extruder http://www.thingiverse.com/thing:1295606 on my Delta printer but for normal bowden extruder it will work too.
The adapter is based on the bowden extruder of schlotzz http://www.thingiverse.com/thing:275593 (perfect designed extruder I think)

Optimized for 1,75mm filament.
I ha