Constant width objects

Here is a print of some curves of constant width that are not circles called Reuleaux polygons.

To see that they are all the same width, here they are on the spine of a familiar book.

I used the STL file from

http://www.thingiverse.com/thing:61275

Note I was able to print all four at the same time in two hours. They aren't very tall, but they were quite far apart on the build plate, so there seems to have been some time advantage in quantity.

There is a discussion in

http://cp4space.wordpress.com/2013/10/27/curves-of-constant-width/


See also the 3D versions discussed in

 http://awesci.com/constant-width-objects-not-spheres/