Goal

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…

A Light Mosaic created by artist Abbey Hoffman as a social-media promotion

Visitor creations

Visitor creations

This testing jig was used to test the reliability of a carrier. It simulated an estimated 5 years of use. I made a small change to the design based on this testing.

I used the in-house ShopBot CNC machine to cut out all custom pieces

I tracked the parts in batches and coordinated with volunteers to conduct final assembly.

Construction drawing of a finished module. The final wall consisted of about 20 100-peg modules.