What is 3D Printing?

 You’ve heard of 3D printing from newscasters and journalists, astonished at what they’ve witnessed. A machine reminiscent of the Star Trek Replicator, something magical that can create objects out of thin air. It can “print” in plastic, metal, nylon, and over a hundred other materials. It can be used for making nonsensical little models like the over-printed Yoda, yet it can also print manufacturing prototypes, end user products, quasi-legal guns, aircraft engine parts and even human organs using a person’s own cells.
 Fantastical? Yes. True? Yes. Here now? Yes.
 We live in an age that is witness to what many are calling the Third Industrial Revolution. 3D printer, more professionally called additive manufacturing, moves us away from the Henry Ford era mass production line, and will bring us to a new reality of customizable, one-off production.
 Need a part for your washing machine? As it is now, you’d order from your repairman who gets it from a distributor, who got it shipped from China, where they mass-produced thousands of them at once, probably injection-molded from a very expensive mold. In the future, the beginning of which is already here now, you will simply 3D print the part right in your home, from a CAD file you downloaded. If you don’t have the right printer, just print it at your local fab (think Kinkos).
 Wall printer uses a variety of very different types of additive manufacturing technologies, but they all share one core thing in common: they create a three dimensional object by building it layer by successive layer, until the entire object is complete. It’s much like printing in two dimensions on a sheet of paper, but with an added third dimension: UP. The Z-axis.
 Each of these printed layers is a thinly-sliced, horizontal cross-section of the eventual object. Imagine a multi-layer cake, with the baker laying down each layer one at a time until the entire cake is formed. 3D printing is somewhat similar, but just a bit more precise than 3D baking.