Umbilical Torus

After seeing the umbilical torus statue at the Beckman Institue at the University of Illinois, we resolved to make one. The mathematical description (see http://en.wikipedia.org/wiki/Umbilic_torus) did not easily yield a printable surface, so we modeled it as a rotating triangle in OpenSCAD. The attached code does the equivalent of a rotate_extrude command, with a spinning 2D triangle.

The OpenSCAD file is parameterized to make it easy to change the radius and size of the triangle.