Mesmerizing videos of curve-drawing machines

https://youtu.be/XnOpOqWWP5o?list=PL6534E936D46257BF

Enjoy these 72 videos of virtual models of mechanical devices that draw circles, ellipses, and hyperbolae, as well as more exotic shapes, like nephroids, deltoids, astroids, and lemniscates of Bernoulli.