The spinning top is one of the oldest and seemingly simplest toys devised in human history, but that doesn't mean we can't improve it. Disney Research has come up with a new algorithm that allows it to design a stable spinning toy out of almost any shape. Researchers found that shapes that fail to maintain a balanced spin as a solid object could be analyzed before construction to optimize its center of mass for rotational stability -- that is to say, the algorithm tweaked 3D meshes to create hollow, interior spaces that keep it balanced. Using this method, the team was able to 3D print tops in the shapes of teapots, asymmetrical ellipsoids and breakdancing armadillo without fear of them toppling over.