Too young at 13? If he can handle an iPhone, XBox and Facebook, then he can handle a 3D printer.

It will get him out of the house and into the workshop, and he might learn some useful skills.

I would make sure that he researched the development of 3D printers so he has a good background knowledge. He will need help learning to use a CAD program, but that knowledge is no burden to carry.

Old Man Emu