I resurrected the Bicycle Chain Spirographs for Biddeford's Merry Maker Fair. They were a standard offering of Bike Part Art at public events prior to Covid but I wasn't sure what to expect now. Happily, children still found them engaging and Adults had a moment of nostalgia to when they first came on the scene in the 1960's & 70's. The challenge of pressing down and to the side at the same time with a colored pencil had a couple kids participating more than once. I also tell the story of the inventor Denys Fisher. When I first created these, there was very little information about him but now there is more:
A Biography written by his son! - https://denysfisher.com/
A BBC video: https://www.youtube.com/watch?v=vBvUahtCwqY&t=47s
Also many online sources for the Math behind this much loved and now nearly Vintage toy.