A model of the famous toy known as a spirograph. A circle of radius r (see blue circle below) is allowed to roll around the inside of a circle of radius R (see black circle below). We assume that the ...

Today, there is a resurgence with Spirograph even with adults. Heather Holm speaks fondly of her set on her blog, Spirographicart.com. “The only toy I still have from growing up is a Super ...