Bike Part Spirograph

Spotted at the recent Cedar Rapids Mini Maker Faire by Steve Hoefer. Looks like a piece of hardboard with a circular hole in it, lined with bike chain, to make an improvised “ring gear,” with variously-drilled chain gears and sprockets that roll around inside it to guide the pens. A similar idea was published by Instructables user hunrichs back in 2008, but I don’t think this is the same maker, and I don’t think Steve managed to get his or her name. Can somebody help us out? Who made this?

Mini Maker Faires Are Just as Great as Full Maker Faires

More:

• DIY spirograph machine
• Hypotrochoid drawing robot
• Spirograph from old CD-ROM
• Adafruit’s business card makes art!
• PIC-based laser spirograph