Yo-Yo Mk.II
This is an improvement on my old yo-yo design, http://www.thingiverse.com/thing:39356
The main improvement is that this design allows two small panhead screws to be used to hold the yo-yo to the axle; the previous design relied on friction. In this design, the screws sit nicely in their own countersunk hole. A cutout on the outer face of the yo-yo provides room for you to put, say, a 3d printed medallion or other decoration.