Lewihe Play real 30mm layer fan duct

Before you read: This is my other better design: http://www.thingiverse.com/thing:1637559

To continue the work for my customized mini printer I missed the layer fan to be controlled by the software. A software controlled fan is a must for some tricky prints... As usual I couldn't find any design, so I made this thing. Fix the 30mm fan with some little screws and add it to the RIGHT of the extruder using the existent M3 screw for the 40mm fan. I didn't had a better idea than using a 30mm fan d