This mechanism demonstrates a surprising way to generate an ellipse by using a four-bar linkage. The shape of the ellipse can be defined by the path the intersection point of the two crossing bars follows. This fact is analogous to another neat way…

Applying the planar puzzle mechanism of the Magic Disc puzzle to a three-dimensional form yields an interesting and challenging coordinate motion puzzle.

This is a cute graphical computing device which finds the roots of a quadratic polynomial. Stretch the (included) string between two scales representing the coefficients of the polynomial, and it tells you the roots! This device is based on an…