THINGS TO KNOW ABOUT 3-D PRINTING

■ The process is also known as additive manufacturing. It builds an object in layers, while traditional manufacturing such as machining cuts away material, or subtracts it, to produce an item. ■ 3-D printing was invented in the 1980s and has long been used by aerospace and auto manufacturers. It has captured the imagination of the public as patents on original 3-D printing technology expire and 3-D printers become cheaper. ■ The process takes more time than traditional manufacturing. It can take less than an hour for a small object like a ball bearing that fits in the palm of your hand, or several hours for a larger object. ■ Many 3-D printers use plastic, but some can produce items using nylon, ceramic or other materials like sugar. Metal 3-D printing is also possible using layers of metal powder melted together. ■ Printers use different technologies. With“fused deposition” modeling, plastic wire from a spool is fed to a nozzle, which heats and liquefies the plastic, then draws it onto platform layer by layer. With “laser sintering,” a roller spreads powder on a surface and a laser draws thin lines in the layers of powder to melt it together in the shape of a model, with the process repeated for each layer. ■ The 3-D printing industry has quadrupled over the last five years, with more than 300 brands of low-cost 3-D printers, at an average price of $1,250, according to an annual report on 3-D printing called the Wohlers Report. High-end machines used by companies like General Electric and Airbus can cost hundreds of thousands of dollars, with some machines priced at more than $1 million. ■ 3-D printing designs are available on websites like thingiverse.com and pinshape.com. You can buy 3-D printed items on websites like shapeways.com. Sources: materialise.com, CloudDDM, AJC research