Modified Greg's v6 extruder with window

For use with a groovemount plate, or J-head mounting plate such as http://www.thingiverse.com/thing:381348.

This modification allows you acess at the top of the hot end so you can see why your filament won't go in. Should be just enough room to stick a screwdriver in there and give it a little help.

Update 12/21/17: Been running this for years, works great.

Update 7/18/18: Added version for E3D v6 (including 4.1mm bore for the bowden tube used on the universal version), also upload