ElectroHarmonograph - i3Detroit
https://www.i3detroit.org/wiki/ElectroHarmonograph
A Harmonograph is 19th-century mechanical device which draws geometric patterns based on the motion of pendulums. (For a real example, see Marie-therese's Maker Faire project - A 3-pendulum Harmonograph. Also, search youtube for videos like this one) By adjusting the physical parameters of the device, and initial conditions of the pendulums, you can vary the patterns it can make.
i3 Detroit V2.0 | i3 Detroit
http://www.i3detroit.com/?p=852
"So we are getting closer and closer to moving into our new space in Ferndale and oh boy what a space it is. With 8000 Sq. Ft. of space and lots to look forward to we thought we would share some photos from this past weekend"