I designed this originally to work with the Modder Board. I have added the bracket for stock board users. Please let me know of any clearance issues. 

NOTE - You will need to download a model to push out the X endstop. I will work on a model soon for that if you're unable to find one. 

Printing 

4 walls, 0.2 layer height or greater, 50% infill. 

Building Instructions:

1. Install 35mm screw into mounting plate bottom hole(for stock board users) or all 3 screws before putting together. 
2. Put together belt bracket - user 15-20mm M3 screws
3. Install bracket onto linear rail with 4 M3x5mm
4. Install Bracket/Rail onto extruder