Making It Real With 3D Printing

With a 3D printer that costs less than $3,000, you can start your own mini manufacturing operation -- and use open source software to create surprisingly complex designs

The thrill of 3D printing is that is bridges the virtual and the actual. Based on manufacturing technologies developed decades ago, the 3D printing process begins with carefully wrought 3D design files and ends with the robotic arm of a 3D printer flying around to fabricate physical objects of plastic or metal. It's the darling of hacker and steampunk communities and the hope of many who'd love to see a boom in small-scale manufacturing.

At the high end, 3D printers aimed at the aerospace market cost a king's ransom and produce solid hunks of titanium. Cheaper, more versatile laser systems fabricate objects out of melted metal or plastic powders. But the real excitement centers on low-cost 3D printers that use a process called fused deposition modeling (FDM), where plastic wires are melted and deposited to form finished products.

FDM machines are essentially very precise hot-glue guns connected to robots. The printer moves its nozzle to coordinates specified by control software to draw a single layer of the object. The nozzle then deposits the next layer on top of the previous shape. The machine repeats this process dozens of times until it creates a fully formed object, ready for use...