A spinning top (fighting spintop) that competes with the overly expensive Beyblades. Made by Boris (9 years old) on a RepRap at the TU Delft. It will fight other Beyblades and win. You still have to bring your own launcher (either with a ripcord or motorized).

Let it rip! http://www.youtube.com/watch?v=bPoYmsNnrwI

You basically only have to 3d-print these two files and connect them with bolt and nut and you're done. But here comes the catch! To give the spintop some weight the base has room left out for a washer (disk-shaped ring with a hole in the middle). The trick is to wait until the moment the printer is ready for closing your model, press pause and place the washer in the model.

In our case the PLA didn't adhese to the metal of the washer, therefore we covered it with tape.

If you want to see how it was made, check out the trailer of Boris and the printing process: http://www.youtube.com/watch?v=qiNS47nDTB8