Sadistic Monster Creates a Smart Cannon That Makes You Step on Legos

The ultimate way to protect your home against shoe-less invaders.

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The same quality and durability that allows Lego bricks to be passed down from one generation to the next also allows the brightly colored building toy to be weaponized in the worst way imaginable: inside a foot-tracking cannon that deliberately sends the pieces sliding underfoot as someone walks by.

Adam Beedle is seemingly a glutton for punishment when it comes to kids’ toys. After building an automated turret for a Nerf blaster that sends foam darts hurtling right towards the face (their face, in particular), Beedle has constructed another weapon of mass annoyance. This time, it’s a camera-equipped, custom-designed blaster that greatly increases its target’s risk of stepping on one of the most painful objects known to humanity: the Lego brick.


If you’re not wincing in pain at the idea, take a moment to watch Beedle’s very unscientific experiment to find the most painful Lego brick to step on (don’t worry; he doesn’t enlist any unsuspecting friends or family to endure this torture). Although it was a simple one-stud brick that caused the most pain, Beedle instead designed and 3D-printed their elastic band-powered launching mechanism to fire standard two-by-eight bricks, which are still no picnic to accidentally discover underfoot.

I built a robot that makes you stand on lego

A basic computer-tethered webcam attached to the launcher and powered by the OpenCV computer vision library specifically targets the human foot, although given the limited image quality of the cam, the addition of red socks greatly increases the cannon’s accuracy. When a foot is targeted, the cannon sends the plastic bricks sliding across the floor towards it, creating a minefield of pointy studs and sharp plastic edges.


If you’ve got roommates notorious for sneaking into the kitchen and stealing your food, a contraption like this guarantees you won’t have roommates for much longer.