Handcopter

Its a little spinning helicopter, the blades can be printed on their side with no support in the two blade version, a more than 3 bladed prop will need printed on its top or bottom with support under the blades. 

If you want this to fly you will need to use either a lightweight filament or less filament, such as 2 perimeters and 3 top and bottoms layers with 5% infill. I recommend cutting the handle in the slicer to give it a small flat side so you can print it on its side, but you can print it standing up.

The Free cad Project has Parameters for the angle of the blades at the hub, the ends, the blade width and count and most of the dimensions. Feel free to play with it and see how you can make it fly best. The angles I found work best are where they are set with 35deg at the hub and 15deg at the end of the blades. the reason you might want the ends of the blades to have less of an angle is to reduce turbulence and drag though it honestly probably matters very little.