How to build a big gun with a 3D printer

Should probably have titled this one, "Smart kid kills the world" because this kid seems a little crazy to me. But that aside I've been trying to visualize how this 3D printer thing works. I've seen dozens of stories about how they're using this technology to build everything from spare body parts to automatic weaponry. Now thanks to Roger Ebert at least I understand, "How to print out a firearm in the comfort of your own home."



Calling it printing is somewhat deceiving. It's more like you design it in 3D and then build the model from the specs with a fairly simple machine. They're using plastic in this video. Not sure how that would work with metal. Would think you need a much different setup to build that. And I'm still mystified on how they would build body parts. I mean what do they use for the human tissue in the construction? Nonetheless, rather astounding technology.