BCN3D++B Single Bowden extruder

This is a remix of the DaniSaez Remix (http://www.thingiverse.com/thing:419278) of my BCN3D+ Bowden extruder (http://www.thingiverse.com/thing:406531). Thanks to the great job of Dani, he greatly reduced the carriage width, but he needed to relocate the fan in the front of it. As I like to see my parts printing (call me maniac...), I decided to redesign some parts to put the fan in the back as originally, and this is the result.
Dani found An other issue. How to attach the small 25mm cooler fan to the carriage. He decided to glue it to the carriage (simply and effective), but I wanted to do it mechanically (Call me maniac again...;)). I've used the original RepRapBCN support adapted to my BCNozzle (It seems that I've the first version...).
Other improvement (in fact is the main improvement. Thanks to it the fan can be placed in the back...) is that the original layer fan support, now is has an other functionality, is the belt clamp too.
All the materials in the original things (