Dan Goldwater was part of SquidLabs and now has a company called Monkeylectric; he builds crazy bike lights that, among other things, can display animations as the wheels spin. Dan approached me with an idea to build a volumentric display based on his bike-light technology.

I ran the numbers on the loading conditions due to the gyroscopic forces in a two axis rotating system. As it turned out the loads were fairly high, but still relatively manageable with a heavy duty bicycle wheel. I was mighty busy building robots at the time so Dan had another volunteer help with the actual construction, paying due respect to the load calculations I had provided.

The final product has been at multiple Maker Faires as well as Siggraph. There is also an Instructables page that has the full writeup alogn with high resolution pdf's of the free body diagrams and analysis I performed for the project.