Oftentimes, even the simplest of machines can produce intricate results, and that is perhaps best demonstrated by Instructables user Dee et Ko and their pattern making device. Reminiscent of a Spirograph, it consists of just a few parts — two stepper motors, an Arduino Uno, a motor shield, and a marker — though it’s capable of some intriguing patterns.
https://blog.arduino.cc/2021/12/15/produce-pretty-patterns-with-this-arduino-powered-project/