More affordable than ever, 3D printers are booming for personal, professional, and educational use. Here's everything to know before you buy one, along with the top models from our hands-on testing.

At 9:00 a.m. last December 14, a man in Orange County, California, discovered he’d been robbed. Someone had swiped his Volkswagen Golf, his MacBook Air and some headphones. The police arrived ...