Symmetric-hinge Polygon Elements

Polyhedron components with symmetric(unsigned) hinges. Also, now with octagon.

The previous kit http://www.thingiverse.com/thing:4934 had larger facets and signed snaps, and assembly was a puzzle. This script resolves these problems by using only one symmetric hinge. I adapted a concept from http://www.thingiverse.com/twotimes to design these hinges.

These parts are snap and dimensionally compatible with other things tagged "Elements". They are also useful starting blanks for building up