Harmonograph #2

Here's a look at Harmonograph #2, a 3-pendulum device. The 'table' stands about 30 inches high. The drawing surface is about 48 inches high. The black rectangle is where a sheet of paper is fastened. It is on a pendulum which hangs from a gimbal, allowing a circular or elliptical swing. The other two pendulums each swing on a single plane but at right angles to each other. Where these two arms come together there is a hinge which holds the pen (near the red spring-clip). The frequency of each pendulum is determined by the height of the weight on the bottom section of each pendulum arm.
This harmonograph doesn't work as well as my first one, which clamps to a table top. There is too much 'play' and friction in various parts of this machine, which all adds up to dampening and sapping of the energy of the pendulum swings. These problems are resolvable without redesign or rebuild. A smaller, lighter drawing pad. Lighter drawing arms and much lighter hinge. Stiffer legs. Those would all help.
I don't have a video clip of this one yet but I do have a few scans of drawings done on it. See below.

A simple harmonogram (a harmonograph drawing, 8.5 x 11 paper).

A more complex harmonogram

The simplest type of harmonogram, with all the weights set at the very bottom of the pendulum.

 The drawings below were made while I was setting up and tweaking the harmonograph. I made one drawing on top of another to save paper. So the drawings have a kind of child-like imperfection, with wobbly, scratchy, jerky lines, skips and stutters. I thought some of them were interesting, and that I could make them more so by reworking them a bit. A lot of the lines were made with Sharpie pens, so I dribbled rubbing alcohol in spots here and there on the pages, which made the ink dissolve and run in interesting ways. Here are a few examples:

Example 1: these were done on 8.5 x 11 paper

Example 2

Example 3