Anycubic Chiron Extruder Fan Duct (Front and Rear, Leveling Sensor Compatible)

!!!---Important Updates---!!!
2018-08-22:
Updated new version, it fit the fan better, cost lesser material and more...
Added my print settings for this fan duct;
Added stringing test result for the duct comparison, both tests printed with same setting.

2018-08-21:
The fan duct cannot fit the fan entirely as it is ~1.8mm shorter than the depth of the 40x40x10mm fan, thus some air will come out through the gap between the duct and the fan. I am working on a new version that will fix the i