Drawings made by swinging pendulums

A harmonograph is a Victorian machine: hang a pen from one pendulum, the paper from another, set them swinging, and let friction slowly bring them to rest. The line it leaves is drawn here from the same equations — four decaying swings, nothing more.

Friction decides how quickly it spirals shut. Detune is how far the two pendulums are from being in tune with each other — at zero you get clean loops, and a hair away from zero is where the interesting drawings live.