Pencil-copter blade

This is something I made available elsewhere, but I suspect the service was too expensive to make it popular.

More of an art to this than a science (don't have 3D printer here), thus it's very likely this will need adjustment for correct size and orientation for printing. Plastic should give a little at the hub, but otherwise fit snugly on a typical 6 sided pencil.

The idea here is that of a common toy. Just one of those rudimentary "helicopters" where you use two hands to spin the axle an