The Spirograph is made from 4mm acrylic sheet, cut by laser cutting machine. I designed the Spirograph's gears on Matthias Wandel's gear template generator program.

More pictures and info here: http://lumberjocks.com/projects/215826
Gear template generator by Matthias Wandel - http://woodgears.ca/gear/
3-d router pantograph by Matthias Wandel - https://woodgears.ca/pantograph/
My pantograph reviewed on Matthias site: http://woodgears.ca/pantograph/elyasa...
online Spirograph (a lot of fun, great for kids) - http://nathanfriend.io/inspirograph/