The magic box

A few years back I saw a video of one of the coolest things ever: a laser Spirograph. This is a little device that sucks in a laser and spits out a light show. I was so compelled by the mesmerizing shapes it formed that I had to make my own. And so I did.

Again, not my greatest creation.

The idea is that the laser passes through the hole on the bottom left, bounces off the four mirrors, and exits through the hole in the top. But how does this device make such pretty patterns? Well, that's where the magic comes in.

The green laser bounces off of the four mirrors and makes its way out.

The magic is with the motors. The mirrors are glued on so they're at a slight angle. Thus, any rotation will cause the laser to slightly shift in a circular motion. Turn one motor on and the box will project a circle. Turn two motors on and strange things start to happen. The movement of one mirror on the laser combines with the  movement of another, causing polar-like patterns to emerge, such as deltoids and limaçons. Turn a third motor on, and three-dimensional images begin to appear. Delightful!

Potentiometers and DPDT (three position) switches.

In order to get maximum control over the motors, I installed three 1K potentiometers and three DPDT (on-off-on) switches, one for each motor. The potentiometers control the speed, and the switches control the direction of the motor. Since the motion of the three mirrors is relative to the other three mirrors controlling the laser, only two switches and potentiometers are needed. However, for versatility and consistency, I installed all three. In order to power the device, I use a 6V wall-wart with an audio plug soldered on for easy connection. Hey, it's what I had on hand.

Spiral!

Since none of the pictures I took captured the full justice of the projected images, particularly due to the slow speeds of the motor and the fast speed of my camera's shutter, there had to be an alternative. I'd like to introduce... Spiromations!

I can watch these for years! Each of these was made using a 405nm 20mW laser on white construction paper. As an added bonus, if I project the image on glow in the dark paper, I can cause it to glow!

5-pointed star!

Amazing! There's no need to explain why the laser spirograph is one of my favorite projects. It is simply too cool.

Grant