This is a tetrahelix based on the A quanta module. I thought it would be useful for examining properties of the tetrahelix since the A quanta module is a very irregular tetrahedron: each edge and face is different from the rest.
I assembled this on October 4, 1981. It's made with D-Stix connectors I got from Edmund Scientific (now available at Nasco) and 1/8"-diameter wooden dowels. In my examination of the figure, I computed the the sum of the dihedral angles for the A Quanta Module and came up with a value of approximately 425.26°. The same sum for the regular tetrahedron is approximately 423.17°, and for the mite 435°.