The Most Amazing Lego Gadget You’ll Ever See

They’re called Great Ball Contraptions. All they do is move miniature balls from one place to another—in the most complicated manner mechanically possible. For the Lego Technic-loving designer/engineer, they’re an elite, Rube Golderberg-esque litmus test of skills.

But one epic build by ‘Akiyuky’ may have just put all others to shame. It’s 100 feet of a ball-moving assembly line, constructed over 600 hours, with each new turn representing another ingenious mechanism in moving and sorting. My personal favorite moment happens about 2:00 in, as a triad of catapults launch the balls at a basketball hoop, but only those that make it move on to the next stage.