Laser Spirograph

I used stuff lying around my office to make a laser spirograph—three slightly tilted spinning mirrors at right angles to each other, where the speed of rotation for each can be controlled to make them spin faster than your eye can pick up on. Thus, the light bounces three times (3 degrees of freedom), displaying fun patterns on the wall.

 

For mine, I used a plastic box to hold three computer fans, and just taped mirrors onto each. I wired them up to cheapo potentiometers in order to control the spinning speed for each by adjusting the resistance/current to each motor independently.

 

Here’s what it looked like:

And here’s what it worked like:

If you want to make your own, computer fans and a laser pointer should be easy to find, the circular mirrors can be found at any craft store, and the potentiometers are about $1 each at radio shack. I used a 12V power supply because it was handy, but batteries work too.