Platonic Solids for OpenScad - v0.7

After losing some hair over the issue, and with some help from Marius Kintel, I was finally enlightened as to why my dodecahedron was not coming out properly.

This thing represents some forms of the dodecahedron. In particular, it is combinations of the dual forms (dodecahedron/icosahedron). The .stl files are printed with a radius of 20mm, but you can change that to whatever you want either in the OpenScad, or by scaling.

The 'difference' form is probably the most interesting. It makes