I did a presentation for the Inventors Association on business, sharing and fabrication. To make it more interesting I made a perpetual motion machine during my talk.

It was designed in Sketchup and cut on a CNC laser. It has 16 rare earth magnets. The rotor has north facing out and the stator has north facing in. It has a precision ball bearing and is made of layered hardboard and nylon bolts.

It turns out to be pretty cool. We brought it to the pub a few times and used it to provide perpetual beer.

There is strong cogging since the magnet clearance is 1/16″. Interestingly, there are two stable resting points. One is before the magnets pass each other and the other is right after. Intuitively I was expecting one stable resting point that is with the magnets all as far apart as possible. I suppose the attraction of the other poles gets in there and creates two local minimums in the potential energy curve.

Here’s a video of Sanjay who works for big oil. He is demonstrating the machine but is adding friction with his hand from behind so the machine appears not to work. He’s such a humorous guy. I like the slip up when he says “…I’m sure you’ve guessed it doesn’t work… so the way it works is…” hahaha…

A Perpetual Motion Machine that Actually Works

Well it’s not really perpetual motion, it runs on poop. And worth watching to see Bill Gates drinking poop water and pretending he’s cool with that. 😉