Do nothing machine, B.S. grinder, Trammel of Archimedes, they've gone by all sorts of names, when used for drawing it's an ellipsograph. I show it as a lever that switches back and forth from a first class lever to a 2nd class lever. In doing so it is able to trace out ellipses on the handle. It is an interesting piece that shows how circular motion consists of two sinusoidal oscillations. On the practical side it has commonly been used for drawing out ovals for picture frames.