Double Helix Pump

This is part of a kinetic sculpture I designed called Digital Rain (the rest is my gyroid construction set, listed as a "remixed from"). It's best experienced in person, but since it's in my basement for now, a video will have to do: https://youtu.be/fdcw1tt5CR4

Being modular, you can make this as tall as you want (mine is 10 units high, or about four feet). I power it with a 12V gear motor I picked up off eBay that I run at 6V to get about 15 RPM. It only takes a few watts of power. It's pumping about 1,500 5mm steel bearing balls.