Clocks, they’re pretty simple, right? Spin hands around at three different speeds, pop some numbers on the outside, and you’re done, right? Well, that would do for most people, but not Greg Zumwalt. When his youngest son showed him a video of a watch with an unusual mechanism and asked if he knew how it worked, Greg didn’t just explain it, he designed and 3D-printed a replica.

The strip of numbers along the top represent the minutes, and the number inside this strip is the hour. Despite it rotating in four different axes, it’s powered by just a single motor and a Geneva drive.

Not only does it look undeniably cool but, unlike most clocks that redesign the mechanical system, it’s actually easy to tell the time on this one.