This LEGO Machine Sets Up and Knocks Down Dominoes on an Infinite Loop

It’s important for everyone to have a hobby. Some people hike, others bake or write. For his part, YouTuber Grant Davis makes overly complicated LEGO Technic builds. And lots of people watch them. His latest is a satisfyingly infinite loop of dominoes falling and being set up again. He makes every part of the contraption out of LEGO—the dominoes, the gears, and even the shiny gold lettering. Davis estimates that it uses 4,000 pieces, including magnets from old LEGO train sets. He spent over 300 hours of his evenings and weekends making this machine for us all to enjoy.  

Based on the video above, it looks like getting the mechanism right took lots of trial and error and most of the total time involved. After all, there’s a lot to consider. And a lot of frustrated yelling when things don’t work or pieces go flying. But once he’s finally got it, and the arms smoothly knock over the dominoes and set them back up reliably, it’s just a matter of repeating the process.

Davis’ final machine uses 10 dominoes in a cycle that repeats every seven seconds. The math works out to 123,428 dominoes being knocked over and set back up every day. As he mentions in the video, that technically beats the world record held by Mark Rober, a former NASA engineer. Next up, Davis plans to test out a circular version of this domino contraption so that it’s a literal infinite loop. Look for that and other fun LEGO builds (including a wave machine!) on his YouTube channel.

A LEGO build that sets up and knocks down dominoes on an infinite loop
Grant Davis

If you prefer your LEGO Technic builds with more functional purpose, there’s one that assembles pizzas and tapas for you. And one that makes a hot cup of coffee! Much more useful if your hobbies include eating food and drinking caffeine.

Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.