My friend Chris sent me some photos of this amazing orrery that he comissioned. Created by artist Eugene Sargent, it's a beautiful piece of engineering.
There is a small shaft to the right of the main shaft which turns at one revolution per moon orbit around the earth. The moon orbits smoothly on extremely tiny 2.5mm diameter ball bearings.
We definitely picked made the right decision on the cranking ratio...one fortnight instead of one moon orbit. It’s extremely easy to turn and still gives plenty of planetary motion satisfaction.
Here's a video of its making, filmed by Sarah Moore. Notice the ice caps on the Earth—a nice touch that'll be memorable when the real ones have melted away.
