By Michal Bartlomowicz

Imagine if you could create anything you wanted. All you would need to do is sit down at the computer, open, create, or download the object you want to have, and click the print button. The object would start printing, and once finished you would be able to hold it in your hands. With a 3D printer, you would be able to do this from the comfort of your own home. And amazingly, such products exist.

If you think all of this is too good to be true, your intuition is right…well, sort of. 3D printers are real objects that anyone can buy, and they can make nearly any imaginable shape, but with current technology. 3D printing has come a long way and poses high hopes for the future, but it has several major downsides.

The idea of printing isn’t exactly a new one; the earliest printing methods date back to the third century. However, conventional modern and ancient printing techniques only allow printing in two dimensions, meaning the product will be flat. For instance, the printed ink on this very page is less than 5 µm (micrometers) thick, or about 100 times thinner than the width of a human hair. All products also have to print on some material, which is almost always paper, because the printed product is too flat to be held together on its own.

Creating physical 3D objects has always been much more difficult than simply drawing or painting them. Since antiquity, man has been carving and shaping stone and wood (and later metal), to create his tools, sculptures, and inventions. The industrial revolution brought about powerful mechanical tools that did the “carving” much more efficiently than any one person could do on his/her own. Soon enough, eager innovators modified tools like milling machines and lathes, regularly manned by workers, and hooked them up to mechanisms that allowed the machines to carve parts on demand. The rudimentary system of the 1800s is similar to the workings of mechanical music box. The non-practical method was replaced in the late 1940s when John Parsons and his team developed a method of milling helicopter parts for Sikorsky Aircraft, that worked simply by entering number “punched out” from a punch card calculator used for engineering calculations. The system was a huge leap forward, but could not achieve perfect shapes due to the fact that humans still had to operate the machine. A team at MIT further automated the system in the early ’50s, creating the first practical numerically controlled machine, or NC machine. With the advent of computers happening around the same time, the two merged in the late ‘50s, producing the first CNC machine. By the 1970s, CAD, or computer aided design, was combined with CNC machines, allowing anyone with access to such tools to literally make anything that could be designed on the computer, as long as it was possible with the tool.

However, the process of “carving” can only go so far. Since antiquity, man has also been building and constructing things out of clay, bricks, wood, and steel. Some of these cannot simply be milled with modern CNC machines out of a piece of metal or wood. That’s where 3D printers come into play. 3D printers are additive manufacturing machines, meaning that instead of taking away material, they build from the ground upand they’ve been doing so for over 30 years.

There are several different methods of printing something in three dimensions, but all techniques essentially build the object up from the ground, layer by layer. The machine prints the object one cross section at a time in the same way a regular printer prints pages in a book. Beyond that similarity, there are three main methods of printing with various subsets: laser sintering, lamination object manufacturing, and fused deposition modeling.

Sintering is the process of making objects from powder. Heat is applied until the particles adhere to each other. In laser sintering, a high powered laser is used to selectively harden layers of powder. The process is repeated for each layer by applying a new layer of powder to be selectively sintered, and the previous layer acts as a foundation for the next layer to build upon. Immediately after the printing process is completed, the almost finished product is buried in non-sintered powder. The excess powder is simply blow away by a stream of air, and is reused in the next printing. The part is then further cleaned with water or in a chemical bath to remove any dust. And because the powder works as a foundation for the next layer, objects with moving parts can be made with this method. All sorts of materials can be used in this process, including plastic, metal, ceramics, and glass. Resin can also be substituted for powder, and the process (stereolithography) is very similar.

Lamination object manufacturing (LOM) uses common, easily accessible materials: paper and glue. Laminated sheets, most often (but not limited to) paper covered in a thin layer of adhesive, are cut either by a knife or by a laser to form a cross section of a model. Many layers of these paper cross sections are stacked together and eventually form the finished product. But unlike laser sintering, in order to make certain shapes, support structures must be made during the printing process before difficult structures can be made, for example overhangs or moving parts. Because no chemical reactions are involved in the actual printing of the product, objects can be made to a relatively large scale when compared to the other forms of 3D printing.

Fused deposition modeling (FDM) is simply the process of extruding material layer by layer to form a physical object. Plastic, the most common material used, is melted, and applied where needed, layer by layer. And unlike laser sintering, support structures are needed as a base for many difficult objects, and must later be removed. Compared to other forms of printing, FDM is the most mechanically simple method of printing, since it does not contain any other mechanisms to aid the construction than the plastic extruder. This means that once an object is printed, only support structures need to be removed. FDM also allows different colors to be integrated in the object much more easily than with other methods, as different plastics can be used.

As you might imagine, this layer-by-layer process won’t break any speed records any time soon. From start to finish, an object could take between a few dozen minutes and over a full day to complete, given the complexity and size of objects. Sadly, because they are so intricate, 3D printers don’t come cheap; advanced machines can cost as much as $500,000, but many average devices cost less than $30,000. An entry level FDM machine can cost as low as $14,000, which by any measure is still a hefty price to pay for a printer. Materials can also pack a punch of your wallet. The resin used in stereolithography can cost between $300 and $800 per gallon, and plastics cost more than $9 per pound. By far the least expensive, LOM printers only use paper and glue, one version actually uses common printer paper.

There is always an alternative to buying a commercial product: You can always make it yourself. Makerbot Industries is a company that sells DIY 3D printer kits, called the Cupcake CNC, for as little as $650, and makes nearly anything from plastic that is 4”x4”x6” or smaller in size. The company also sells fully automated, more advanced kits that go up to $1,225 and can produce objects up to 12”x12”x16.” The printers print in ABS plastic (the same plastic that LEGO bricks are made of), and can be easily modified to extrude in clay, silicone, or even cake frosting. All components and software is also open-source, so users can modify their Makerbot.

Makerbots are not the only printers you can buy or make. The RepRap Project, short for Replicating Rapid-Prototyper, is also an open-source project (but without a company behind it) that gives instructions on how to make a functional 3D printer. But the RepRap was designed to produce its own parts, meaning it can self replicate to a degree. While the RepRap cannot build its metal or electronic components, a majority of the structures can be fabricated with another 3D printer.

But what if you don’t have the money to buy a 3D printer and still want to have your creations? The Internet has the solution for you, since there are several companies on the web that will print your design for you, in nearly any material you like. But the price isn’t cheap either; prices range from $1 to $10 per cubic centimeter.

Though 3D printers are really a niche-product aimed at the engineering, designing, and architectural fields, their use is becoming much more widespread. And with new advancements that drop 3D printers into the affordable range, maybe someday they will become as common as the printers that print text and pictures on paper.