A couple ideas for improvement. If you have extra identical motors and disassemble two, you can fashion a rotating power transmission system from the brushes in two assemblies. You sacrifice two motors for each unit, but it's a perfect fit and very reliable (with a cap and rectifier), and you don't have to worry about batteries anymore.
The rectifier also provides a signal that the assembly has completed a rotation, so you can maintain image stability based on actual position, rather than guessing how long a cycle is.
Transmitting power via induction might work, but I was never able to deliver it efficiently enough, so to make it work I had to turn up the source voltage so high that I worried about fires.
The rectifier also provides a signal that the assembly has completed a rotation, so you can maintain image stability based on actual position, rather than guessing how long a cycle is.
Transmitting power via induction might work, but I was never able to deliver it efficiently enough, so to make it work I had to turn up the source voltage so high that I worried about fires.
This advice comes from my 2001 Burning Man art project. A very sad early prototype is pictured here: https://github.com/sowbug/tqw/blob/master/photos/side.jpg. The final installation worked great.