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 ...

[Tuchman] starts with a quick proof-of-concept using an actual plastic Spirograph toy to make sure it isn’t a totally unworkable idea. Unsurprisingly, the plastic is too flexible to give a ...

Master LEGO builder [Yoshihito Isogawa] has been on a roll lately, cranking out a number of robots that make drawings reminiscent of the classic Spirograph toy. For instance, he built an elegant ...