LEGO gun turret targets tender toes

LEGO gun turret targets tender toes

Arduino Team — August 4, 2022

Walking on LEGO bricks is a meme for a reason: it really is @#$%&! it hurts. The design of the LEGO bricks is ingenious, but the engineers didn't consider the ramifications of their minimalist building system. We've seen people do crazy things for internet points, like walk on a bed of LEGO like they're hot coals - or in the case of Adam Beedle, build a LEGO gun turret specifically to shoot bricks plastic under a person's feet. /p>

This project consists of two distinct subsystems: the mechanical turret that launches LEGO bricks and the targeting system that recognizes feet. For the first, Beedle designed a clever mechanism based on a rubber band that locks into place with a rack and pinion. An Arduino Uno spins the pinion with a continuous rotation servo motor. The sprocket has a few teeth missing, so it releases the rubber bands and launches the loaded LEGO brick after a few rotations. Another brick then drops from a hopper and the cycle repeats, resulting in an automatic shot.

Beedle 3D printed all the turret parts and used a second turret motor to provide rotation. The turret also has a webcam mount, which is how the targeting system finds the feet. Beedle doesn't provide many details on this system, but we assume he used something like OpenCV running on a PC to detect feet. The PC would then send a command to the Arduino through the serial port telling it to rotate the turret in the correct direction until the detected foot is centered in the video stream. As he gets closer, he begins to spin the cog to fire LEGO bricks.

From what we can see in the video, it looks like the turret worked as intended. That is to say, Beedle managed to build something that would require him to walk on painful LEGO bricks.