Being able to print your own objects sounds amazing to the average citizen. Need a hose mender for your garden hose? Don’t drive to Home Depot to get it — just print it! Need a replacement part for your child’s toy? Just design it in 3D software and print it! Any object you can imagine can be printed in ABS plastic, including complex gears and objects with intricate details. Many printers can print in multiple colors, too.
Cody Wilson from Defense Distributed famously designed and tested a printable gun that fires a single round of .380 auto ammo. Pistols, it turns out, aren’t that complicated. They essentially need nothing more than a trigger, a firing pin, a chamber to hold the round and a barrel to allow it to accelerate out when fired. Wilson’s innovation was making a gun work out of plastic.