We see the world in three dimensions. Now, we can print in three dimensions, too, thanks to a manufacturing process that has become mainstream in recent years: 3D printing.
What is 3D printing?
A 3D printer uses an "additive manufacturing process" (which means an object is built up a layer at a time). Most 3D printers have a single extruder head, which means if you want to use multiple colors, you may have to print your object in sections, and even then you'll be limited in how the object can be colored. This is why the most common 3D examples are objects like a blue-hued plastic Yoda -- single color printers are most common. But while everyone loves printing Yoda, the reality is that today's 3D printers are being used to print everything from design prototypes to jewelry, crafts, product parts, body parts, and even food.
When stereolithography printers were first introduced back in the mid-1980s, they cost six figures and were targeted at commercial and industrial applications. It wasn't until about 2012 that prices fell dramatically, with printers costing $1,000 as opposed to $20,000. With the price drops came a broadening of the audience for 3D printers: The maker, arts, and education communities all got on-board, as did designers looking for inexpensive, fast prototyping. Prices are expected to drop another 6.4 percent in 2016, according to a report by market researcher IBISWorld.
How 3D printers work
Different printers use different printing techniques. Consumer 3D printers generally use one of two main approaches.
FFM (fused filament manufacturing, also referred to as filament deposition manufacturing or fused filament deposition) printers use a moving print head to build up layers of melted plastic filament in the shape of the object.
SLA (stereolithography) printers solidify resin using an ultraviolet laser (some models use Digital Light Processing projectors, but those tend to be less precise). SLA printers are generally more costly, but they are capable of more accurate and detailed models because of the resolution and precision of the laser.
FFM printers can typically feed a multitude of materials through their extruders. Common choices include ABS, an inexpensive, petroleum-based sturdy and recyclable material, and PLA (Polylactic Acid), a tough, biodegradable material that's both heat malleable and paintable, but it's also more difficult to glue than is ABS. These materials often come in a range of colors, but since most printers have just a single print head, you'll generally print your entire object in a single color.
SLA printers have more limited choices in both available materials and available colors. The material choices will depend upon whether the printer uses the ultraviolet laser or a DLP projector. The resins materials can be be either rigid or flexible, and are more expensive than the plastic filaments used in FFM printing.
While costs for both printers and printing materials have fallen considerably, buying a 3D printer remains a significant investment, starting around $300 and going up rapidly from there.
Perhaps the biggest challenge is usability. Setting up and using printers have gotten easier, but in order to create something, you have to start with something—specifically, a 3D model.
If you're design savvy, you may be able to whip up a design using 3D modeling software and export the finished digital product as the STL file that all 3D printers use to print. For us mere mortals, though, it generally comes down to either using freely available STL files (you can find many free ones at an online 3D object library like Thingiverse), buying a design from various online stores, or creating your own 3D scans.
If you plan to go the scan-it-yourself route, you can use a 3D webcam, available on some PCs (including the maker-friendly HP Sprout, which has a rotating platform option to use with its built-in 3D scanner) or as standalone devices, a 3D camera like a Microsoft Kinect, or use a third-party 3D scanning service.
What else do you need to know?
Before you pick up a cheap 3D printer and experimenting in the 3D world, consider the size of the objects you might want to to create. If your goal is to print foot-long rulers (for some reason), you'll fall short of that goal if the printer you choose can only handle objects smaller 6 inches in height and width.
Another reality check is print speed and quality. You'll be able to knock out a day's worth of chores while the printer is running, with a typical 4-inch model requiring as many as 12 hours to print. As with ordinary printers, print speed also depends on print quality.
Finally, consider what kind of output you want, and not just because you need to consider what materials you'll use to create your object. If you want very detailed objects such as jewelry or scale models, get an SLA printer since they're better at reproducing the fine details. If you want low cost and ease of use, get an FFM printer.
And while PLA is considered a somewhat more food safe material than ABS, neither of them -- extruded through a 3D printer -- is really safe to eat off of for a variety of reasons. Our advice: Don't even think about printing plates, cups, and spoons.
If you're on a tight budget, and willing to make some compromises, the $349 M3D Micro 3D Printer is a great starter choice. This FFM model will create objects of less than 5 inches, and uses a variety of materials, however it's slower than other models we've seen.
For enthusiasts with a larger budget, we recommend the $1,250 Aleph Objects Lulzbot Mini, which impresses with its ease of use and range of features. This FFM printer supports printing objects of just under six inches, it supports an impressive range of filament materials, and it comes with a customized version of the popular open-source Cura 3D software.