The Spectrum exhibit sponsor requested that we include a giant ‘Lite Brite.’ I thought that we could do even better and create a color-changing version, but the complexity and cost of the obvious solution (RGB LEDs and rotary encoders) was prohibitive. I invented a simple mechanism that consists of 4 parts per peg (2 custom parts, an o-ring, and a dowel pin), and has proven reliable over the years.
Design and Manufacture
Each peg assembly would go through thousands of cycles, and there would be a couple thousand peg assemblies, each with a potential for failure, so I took extra steps to ensure longevity. See the photos below for more details…