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Inspired by Robert Howsare’s Drawing Apparatus, a time-step simulation of a similar apparatus was developed. Each trace was made of thousands of straight line segments, one for each rotation of the turntables’ drive motors, and enough to create a closed figure. Suitable gearing was modelled to simulate standard (North American) gramophone speeds of 16⅔, 33⅓, 45 and 78⅕ rpm for each of the turntables. Drive crank lengths were derived from standard record sizes. The initial starting angle of each turntable was also modelled.

Three simulation runs were chosen and superimposed. The result was plotted on “A” size vellum using 0.3 mm ceramic drafting pens. Total plot time  at 90 mm/s: 22 minutes.

Code available on request.

(update, 2026: Code available on request if I can find it. I have implemented this project from scratch at least three different times because I forgot I’d done it before. You might say I’m forgetful, but I say I get 3× the joy of discovery this way …)