Artist Rosemarie Fiore converted an amusement park ride called The Scrambler into a giant drawing machine. The specially-outfitted Good-Time Mix Machine produces huge geometric paintings that resemble the output of a Spirograph.
From the project description:
I connected a gas generator and air compressor to buckets of paint and secured them into the seats of a Scrambler amusement park ride. Once the ride was in motion, paint sprayed out of the benches onto vinyl tarps placed underneath. The result is a series of enormous hypocycloid designs which recorded the hidden patterns created by the ride as it turned.
Link to project page, Link to video (via Information Aesthetics, thanks Mike Love!)