"Some researchers working for Disney have recently set up a method enabling any kind of object to spin around like a spinning-top. To find the right balance for the object, they have to study its shape and let some empty hollows inside in order for the mass to be right balanced. If ever it's not enough, they may add some metal pieces inside."
A great idea showing some potentialities of 3D printing.
Click on the picture below to watch the associated video:
