I made a very simple mechanism for a drawing machine. It only makes one motion -- but, like the back and forth machine, if it does it many many times, it makes an interesting drawing. I tried it both with pencils and with markers: Four drawings made with the same machine. Click on the image to see the drawings a little larger. I like the wing-like shape it makes. Image of the machine coming soon.

This machine responds to the level of the sunlight on our (very bright) porch. The machine is made with a 2-sided screen (shaped like a roof), with a motor that hits the screen with some weights attached to a dowel. If it is really really really bright, it hits the side of the "roof" coated with blue paint; if it is not too bright, it hits the yellow side. Here's the machine: The mechanism of the summer sun painter.

Here's the machine I used for the spin art: Here's the machine that I made as a platform for the spin art machine. It's based on this spin art turntable design on the PIE Network site.] The simple, single direction turned on and off with a touch sensor. Here's the program: A program for the spin art machine that starts and stops with the touch sensor.