Against all instincts, a sphere is not the only geometric shape that has a constant diameter. There are an infinite amount of others, of which the Meissner Tetrahedron is the coolest. This set contains 4 shapes, each different, but with the same constant width of 35mm: I know this isn't the first collection on Thingiverse, but I CAD'ed them myself, hence no credits to others. Well, okay, credits to Reuleaux and Meissner! Watch them do their thing on http://youtu.be/_8Fe-OLr42Y If you make them, please share the picture!I had to sand away some support, as well as little blobs on the top. However, it should be possible to print with barely any support, and therefore (almost) no sanding.