40x40 Fan cover / diffuser

A simple cover for 40x40 fans which acts also like a diffuser. I made it for low noise and low airflow impact.

*cover_difuser_40x40_CCW.stl* is for fans that spin in a couter-clockwise direction when viewed from the hub side.

*cover_difuser_40x40_CW.stl* is for fans that spin in a clockwise direction when viewed from the hub side.

The CCW cover can be used on a CW fan and vice-versa, but there may be a little bit more noise comming from the cover.

If the part looks to be too big, scale it down to 3.937% (the STL export script has a bug; it outputs the part in inches, while I'm using mm)