BCN3DR Modular Hotend Platform

This is a modular platform for the BCN3DR printer, which allows for mounting different hotends like the E3D V6. This is an attempt to bridge the gap between the 3DR Simple community and the BCN3DR printer community.
To select your hotend mount, look for any 3DR simple hotend mounts.

UPDATE: Mounted on the printer, I had to add a washer on each arm to make the 47mm spacing of the arms match up with the carriages/towers. Works perfectly!

### Auto-leveling mount
This design includes the auto-leveling sensor mount, which is easily removed in the .scad file, as it is already configurable.

### Fan mounting
I had to remove the fan mounting corners to make this fit the arm width of the BCN3DR (it is wider than the 3DR Simple due to the belt driven carriages). I simply used a fan system which mounts to the hotend, for which there are more compact options (i.e. saving bed space & avoiding tower impacts).

Credit to @darco for the great 3DR Simple design I tweaked in OpenSCAD. I am