NEMA17 Bowden Extruder M6 1.75mm

UPDATE JUL.22.2018:
i made a DIRECT variant of the original beltless design for 1.75mm filament. the heatsink mount is a bit tight so i'll forego the clamp for now, but i'll fix this in the final revision. requires 4 x 25mm M3 screws, L-bracket, 4mm OD bowden tube running down the length of the heatsink.. i guess the clamps will need 2 x 10mm M3's. the original (light blue) design is still running problem free but i'm going to try some direct extrusion since i'm using a moving XY plane/bed