This is a Remix of another fan blade design. I tried using the original design at https://www.thingiverse.com/thing:1822959 but the hole on the coupling was too shallow to stay on my motor, and too small to drill a correctly aligned hole through. Thus, this larger blade was created, with a pre-fabricated hole through its center, eliminating the need for any drilling. However, if drilling is needed, the hole is present to promote the correct alignment of the drill bit. I have included 2 similar STL files, with the only difference between them being the diameter of the axle they will accept.
Overall volume: disc of 100mm x 100mm x 5mm
Outer diameter: 100mm (3.937in)
Outer circle thickness: 1mm (0.039in)
Blade pitch: 30º to the horizontal
Blade thickness: 2mm (0.079in)
Axle diameter: available in 2mm or 3mm (0.079in or 0.118in)