From pens to prosthetics, from working handguns to human tissues complete with blood vessels, 3-D printers can now create a bewildering array of functional objects.
The price of entry into this rapidly developing technology has dropped to under U.S. $500, putting these powerful tools within the reach of almost anyone with a PC.
But as with any new technology, there’s much you should know about 3-D printing before you whip out your credit card. These printers work in various ways and have vastly different capabilities. Not surprisingly, a typical $1,000 printer has a lot more limitations than those costing upwards of $10,000. So before plunking down your money, here’s a quick introduction to 3-D printers and 3-D printing.
Three ways to build things, one layer at a time
Current three-dimensional printers create objects by depositing materials in extremely thin layers, building up a programmed shape layer upon layer. Most 3-D printers use one of three basic technologies. The least expensive printers, those selling for under $3,000, use an extrusion process. More expensive models typically use stereolithography or laser sintering.
(A forth 3-D printing technology — liquid 3-D — is still in development (more info). But it promises significantly faster printing and finer resolutions.)
There’s a good reason to know a bit about stereolithography and laser-sintering printers, even if you’re never likely to purchase one. As your 3-D creations become more complex, you might employ a service bureau that uses one technology or the other.
Here, in short, are the three processes:
- Extrusion printers (see Figure 1) build objects by pushing out heated beads of polymers — most commonly plastic, but also biological polymers — through one or more jets (see Figure 2), somewhat like an ink-jet printer shooting inks onto paper. Extrusion printers typically cost between $500 and $3,000.