Nova Plexus

The design was inspired by a sword dance, performed by the Georgian State Dancers in the mid 1950s. The dance finished with twelve flexible swords locked together and held aloft by one of the dancers. I didn't realise that the swords were flexible and spent hours over many months trying to devise a structure built from rigid cylinders that would hold itself together.

Some years later, I found a way to prove that such a structure was impossible. I began to think about the minimum departure from the cylinder's shape that would break my proof and allow the sculpture. This was something of an obsession and I made hundreds of sketches over the next five years. I settled on the design in 1975 and made my first wooden prototype in 1976. The refinement that made the final design possible was to discover the construction of the hyperboloidal surfaces of the little necks at each end of the rods so they would lock into place in a pleasing manner.

So In 1978, over twenty years after seeing the dancers, I had a workable design. I wrote a computer program to draw the hyperbola and photo-reduced the curve. From this photo, Monty made a form tool, accurate to about eight microns and turned the first set of rods in mild steel. They held together but not as tightly as my calculations suggested. I recalculated the dimensions allowing for the elasticity of the steel and Monty tried again. This time it was perfect.

Some years ago, I received an email from George Hart who had seen a Nova Plexus and made his own from twelve pencils. As a result of this 'introduction' I was invited as a keynote speaker at ISAMA 2007. So my little toy has been useful in promoting my career too.

Nova Plexus is back in production and soon to be launched by twobrassmonkeys.com. They are making 474 licensed copies to complete the original edition of 500. I have no idea how many they can sell.