One piece construction kit

 

Dodecahedron

Reinforced Octahedron detail

Reinforced Octahedron

Solidworks screen dump showing diameter which fits with 120mm diameter cd's and a 12.5mm distance between cd edges and polygon edges.

Truncation shapes and side lengths for the polyhedra made from the kit.

Tetrahedron stack. From the bottom, the joins are shared edges crossing at node, shared face, shared truncation edges. Bit of dowel in the middle helps support it.

Dodecahedron

Calculation spreadsheet screen dump. The actual spreadsheet can be found here.

Hi

This post is bit of a carry-on from the previous one, and at least some of the pics in the previous post apply. I've released the STL file for a single piece construction kit which uses CD's, rubber bands and 2.6mm bamboo rods to make constructions - all the regular polyhedrons plus tessellations and other forms. This post is a bit of a pre-hack, writing down and drawing the geometry required for forming truncation sides in the construction. I've already done some work based on the hacks, making a truncation side for an octahedron which makes this construction more secure.

It does this by joining some sets of 3 sides to each other making a rigid form not present in most of the "pure" octahedron subassemblies. The square side construction is made from a bicycle rear cog.

Up till now I've made cubes, tetrahedrons, octahedrons and dodecahedrons using the cds-as-sides-method. I haven't been able to make icosahedrons yet but have a few ideas. 

Happy Constructing, Regards  Steve Nurse