E3D extruder mount for TubularBot and Prusa i3

This part attaches directly to an x-carriage mount via 4 M3 screws. It is designed to fit Greg's accessible extruder. The lower portion dovetails with the E3D fan shroud to redirect the air from the fan away from the heated bed.
Note: I updated this part design on March14th, 2014 to improve the fit of the E3D fan shroud/heatsink with the bottom of the extruder mount. I have also more completely enclosed the chamber, leaving two mounting holes and access holes for the 8-32 screws. This part should be used with the E3D mounting plate also on this site for best results.