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.
Dee et Ko began this project by laser cutting a pair of discs and arms, along with a base plate, out of a thin sheet of acrylic and then attached them together with machine screws. Next, each stepper motor was mounted underneath the base plate and connected to a dedicated A4988 motor driver on the CNC shield. Finally, a marker was placed at the intersection of the arms so that it hovered just above the paper.
At its core, the code relies on just a couple of parameters in order to generate the resulting pattern, namely the rate at which the left disc rotates and the rate for the right disc. Eventually, these might be read in from an external sensor or a potentiometer for on-the-fly control, but for now they’re constants.
As seen in Dee et Ko’s demonstration video, this DIY device can draw ornate designs across a canvas using only a marker and two steppers. More details can be found in its write-up on Instructables.