Rollerstruder: filament feeder / driver / extruder

This is the filament driver I used (together with my hobbed bolt) sucessfully on my Ultimaker for the last 10 months (and this is PLA!)
It was designed originally for 3 mm but it would work alike with 1.75 mm as it boils down to how to the hobbed bolt (I ran it successfully with ~2 mm trimmer line filament)
This thing is in progress, though it is currently revision 5.3: I just should stop spending days on it since it is extremely reliable (much more than what I had stock).
It is written