Beefed up Extruder unit for the MakerGear M2 and E3D Hot End

Beefed up the unit a little bit and added a second clamping bolt to give a more even clamp action on the filament... I printed mine in ABS with 0.2mm layer height and it worked great - you may just need to file the bearing slot smooth.

There are also two holes to allow an m3 grub screw to clamp the hot end, with the further option of a front bracket held on by 2 x m2.5 screws.

I included two models of the extruder, one is just the STL, the other is with mesh mixer supports baked in. It wor