That’s what I said when I read the title of this project page on Instructables, except I subbed out “on earth” for something more typical of my daily vernacular. Anyway, these clocks use marbles or ball bearings to show the time. In this instance, one ball bearing represents the hours and the other shows the minutes ticking rolling by.
The maker Gammawave created this one using RP2040-driven electronics, a few 3D-printed parts, and a special handmade enclosure.
While most marble clocks feature multiple balls, Gammawave wanted to rework other designs they’d seen into something more simple, so this clock tells the time using just two elements. Each comprises a stepper motor-driven spiral, a magnetic vertical slider, and a steel ball bearing.
How does the clock work?
The magnet on the vertical slider attracts the ball and lifts it up the spiral as the latter rotates. The position of the ball on a vertical scale indicates the time. When the ball reaches the top, it is knocked off the slider and rolls back down to the bottom, where it reunites with the slider and gets picked back up again. The closer a ball is to the top of its spiral, the higher is the number it represents. So when the hour ball is at the top, the hour is twelve, and when it’s at the bottom, the hour is one. Similarly, when the minute ball is halfway up the spiral, we’re at half past the hour; when it’s nearly at the top of the spiral, we’re about to tick over into the next hour.
User-friendly touches
Gammawave added little ruler markings on the slim white panels to the side of each spiral to make it easier to read the time. The project also features a small Raspberry Pi-friendly digital display that shows a 24-hour clock, but you can switch this off if you prefer to tell the time in hard mode. The display also has some buttons that let you set the time and control the LED lights that illuminate the sliders. A real-time clock (RTC) module keeps accurate time, and a Hall sensor detects the home position of each spiral/magnetic slider pair. All of this is controlled by Pimoroni’s Pico LiPo microcontroller, which is built around our RP2040 chip.
The box housing everything is made of acrylic and wood. It features a reset button, a power socket, and an external RTC battery holder at the back. A couple of clear plastic drinking bottles were repurposed as enclosures for the 3D-printed spirals.
So many instructions
This maker spent a lot of time compiling an extensive Instructables post, so you have everything you need if you want to set about building your own spiral clock. I like this as a more functional, yet similarly calming, alternative to those Newton’s cradles everyone had as a desk decoration in the 1990s. What were they even for?
