Extended high flow fan duct for Anet A8 with autolevel sensor

This is version 2: The distnce to the nozzle has been reduced and the airlow in direction to the nozzle was reduced.

This is a duct optimized to maximize the air flow and to compensate the additional diatance between fan and nozzle due to this autolevel sensor support:
http://www.thingiverse.com/thing:1911146

Without this sensor support the duct might colide with the nozzle.

The design is kept basic and simple and is easy to print. No support is needed and the overhangs are limited to