I'd love to have a plotter. (But for the pen lifting as another pointed out) the plotter seems to be being used as a modern day harmonograph (https://en.wikipe

I'd love to have a plotter. (But for the pen lifting as another pointed out) the plotter seems to be being used as a modern day harmonograph (https://en.wikipedia.org/wiki/Harmonograph https://en.wikipedia.org/wiki/Harmonograph). The analog versions have been amusing us for over 100 years. (One of the best father/son memories I have was a summer spent in Alaska visiting my father. While I waited for the salmon season to begin, so I could start work at the cannery, we had a kind of harmonograph build-off in his well-provisioned garage. I went for the standard design with the paper platen on a rocking pendulum—the pen driven perpendicular with a second pendulum. My dad threw money at his build to pick up some pricey-for-me, small, ball-and-socket joints intended for R/C car/boat drives. Not known for his creativity, he nonetheless came up wth a 4-pendulum design where two pendulums drove the platen and two others the pen. The results spoke for themselves: while my harmonograph designs always spiraled inevitably down to a point in the center of the design, my dad's might appear to be collapsing but then, as a pendulum pair began to move again in phase, the design would suddenly flower again as you watched it being traced out.) Similar to the one I built: https://coimages.sciencemuseumgroup.org.uk/128/977/large_1909_0192.jpg https://coimages.sciencemuseumgroup.org.uk/128/977/large_190... A clever one that, while different than my dad's, likely gives similar results: http://pedrotucker.com/wp/wp-content/uploads/2021/02/harmonograph_drawing1.jpg http://pedrotucker.com/wp/wp-content/uploads/2021/02/harmono... (A "Boy Mechanic" book from the turn of the 20th Century depicts a harmonograph with I believe a double-pendulum: a pendulum hanging off a pendulum. That too would have added some interesting chaos without the expensive ball-and-socket joints needed.)