holds the TwoFolds together?
The TwoFold is like a foam geodesic dome, where each facet is part
of an arch stabilized by its neighbors. There are no springs, latches
or stiffners required. Although the foam pieces are distorted during
inversion and pulled through an unhinged-edge, they return to their
original shape when released. Every foam shape is carefully designed
to nest alongside their neighbors- almost as if they were carved from
a single mass.
any shape be made into a "TwoFold"?
Very few three dimensional shapes are stable in two geometries, can
be inverted through one or two edges, AND fit together like puzzle-pieces
in either stable position.
However, in addition to the three shapes demonstrated, we have constructed
models of a hockey puck into a basketball, a three dimensional Greek-cross
into a cube, the US Capital building into a rectangle, and numerous
inverting regular polyhedra.