How 3D Printers Work

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Additive manufacturing, better known as 3D printing, is the creation of three dimensional objects by adding layer after layer of material. Revolutionary, yet by no means a new technology, 3D printing has been used in manufacturing for almost 20 years. Recently, the spotlight has been shining on 3D printing because of the dropping costs. Personal 3D printers are now affordable and growing in popularity.

3D Printer Technology

Before printing can start, a virtual design of the object has to be created. This blueprint is stored in a computer-aided design file. If the object is being created from scratch, 3D modeling software is used. However, if the object will be a copy of an already existing object, a 3D scanner produces the CAD file. Some hobbyists bypass this process and download existing CAD files from the Web. Once the virtual design is complete, specialized software slices it into hundreds, sometimes thousands of horizontal layers. These virtual layers then guide the 3D printer, helping it to assemble layer on top of layer, until the object is complete.

Materials Used

Common materials used in 3D printing include:

  • plastics
  • wax
  • glass
  • epoxy resins
  • nylon
  • even chocolate

A number of different metals, including precious metals such as gold and silver, are also commonly used. Even alloys like steel can be utilized in the process. Still in the experimental stages are combinations of materials like silicon, calcium phosphate and zinc to produce artificial bone and skin for regenerative medical treatments. In the past, 3D printers were limited to only one material per object. Today, the time of the multi-material printer is finally here. However, being able to print your own smart phone, tennis racket, or hamburger is still a long way off.

Fabrication Methods

Not all 3D printers work alike. One common technology in use is selective laser sintering. In SLS, the layers are created when particles of material are fused together using a high-powered laser. Another type is called fused deposition modeling. FDM unwinds coils of plastic or metal that pass through a heated extrusion nozzle. As the melted material is deposited, it hardens to form the layer. Yet another method is called stereolithography. This uses an ultraviolet curable photopolymer resin in liquid form. As the resin is used to make the layer, an ultraviolet laser cures and hardens it, attaching it to the previous layer.

Industrial and Personal 3D Printers

The most common application industrial 3D printers are used for is rapid prototyping. Designers frequently have to create a full-scale model of their work; rapid prototyping using a 3D printer saves time and money. Rather than sending the specifications to have a model built, the designers can have the model in hand within a matter of hours. Another growing segment of the printer market is the personal 3D printer. Advancements in technology have made these machines quite affordable. Mainly in the domain of the hobbyist, these printers can be purchased for $250 to $2500 from companies like Cubify Cube, Solidoodle and MakiBox.