Their gigantic Nerf gun, quite possibly the world's largest, was built using a 3,000-psi paintball tank, 3D-printed handle, low-pressure regulator, brass adapters and pipes, PVC plastic and wood. The Eclectical Engineering blog has more-specific instructions on how to make your own huge Nerf gun.
"This project involves modification of commercial paintball equipment in a fashion for which it was not intended," the Eclectical Engineering blog says. "The air pressure of the PVC components can be in excess of 100 psi and objects leaving the cannon barrel can travel at extremely high speeds. Some very basic safety practices should be heeded: never look down the barrel of a loaded OR pressurized cannon. Never load it with sharp or extremely dense objects. Never snitch on us for telling you how to make this thing."
The Nerf gun shoots homemade darts, made from pool noodles and toilet plungers, at an impressive 40 mph (64 kph). Rober also loaded the Nerf gun with 3D-printed projectiles that were much more aerodynamic. In fact, the projectiles traveled a distance of 130 yards (118 meters).
The best part of the video shows Rober finally getting revenge on his younger family members, whom he claims always use him as a human target with their Nerf guns.
And a bonus: Eclectical Engineering made its own entertaining video using the extra large Nerf gun destroying watermelons.