Color-changing Light Mosaic

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…

LiteBrite (1)
A Light Mosaic created by artist Abbey Hoffman as a social-media promotion
LiteBrite (5)
p_LiteBrite_ (3)
Visitor creations
p_LiteBrite_ (2)
Visitor creations
LiteBrite (2)
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.
LiteBrite (3)
I used the in-house ShopBot CNC machine to cut out all custom pieces
LiteBrite (4)
I tracked the parts in batches and coordinated with volunteers to conduct final assembly.
Light Mosaic Drawing v14
Light Mosaic Drawing v14
Construction drawing of a finished module. The final wall consisted of about 20 100-peg modules.

Roles

I was project lead, handling design through install.  Many volunteers and a few employees assisted with assembly.  My coworker Josh Smith fabricated the cabinet and installed the lighting.

Location

Impression 5 Science Center, Lansing MI

Completed

2014

2024 Update

It’s been ten years and the exhibit is still going strong!  The o-rings were replaced a few years ago, but other than that, it’s been a reliable installation.