Here's a basic explanation:
The official term for this process is actually "Additive Manufacturing" or "Rapid Prototyping," but the term 3D Printer seems to have stuck. It's called "Additive" because the process adds materials instead of subtracting, which is the case with a CNC machine. Those machines waste materials because they make the object but it will have to be trimmed.
3D Printers make things in layers in order to make exactly what is needed. They can use over 100 different materials, including plastic, metal (even titanium), nylon, and human tissue. They have been used for over 30 years, but until recently were only used by businesses for commercial use and weren't available to everyone. They have become relatively inexpensive and easy to use so that most of us would be able to purchase one, and to understand the process of making things on these printers in our homes. Programs can be 'user-friendly' to make it possible for anyone to understand.
First, you need a 3D printer. This machine can be very small or very large, depending on how large an item you want to create. You'll also need the materials to feed the machine. Then, you must have a computer program that 'understands' when you are telling it to make something. It's possible to use Microsoft Word when creating an object, but the computer needs to know what to do with your instructions. Once you have your concept of the object the way you want it, you send it to the 'printer' similar to when you send a document to your typical printer. The difference, of course, is that it isn't going to print on paper but rather manufacture what you sent to it using whatever materials your 'printer' is capable of. The printer 'understands' what the computer has instructed it to do.
Smallest known 3D printer, about the size of a carton of milk.
These printers are currently available starting at about $100 and up. Some can use multiple materials, some only one. Some can use several colors in one production and others, only one. Producing your object can take an hour or several days, depending on how complex it is.
If you aren't one to design something from 'scratch,' you can scan an item and then have the computer 'read' how it is made, then make a copy, using the right software.
How is this useful? 3D printers can make:
Manufacturer prototypes and models
Parts for virtually anything from engines to dishwashers
Human organs, using human tissue, especially using the person's own cells to avoid rejection
Prosthetics: Artificial limbs, eyes, etc., braces, and possibly dentures
Our military has used it to make unmanned drones
In theory, you could make all the parts necessary to make another printer
Here's an article about 3D printing as used by Hasbro, the toy manufacturer:
If a child wants to connect his Legos to Lincoln Logs and you have a creative side, you could design some kind of adapter and print that out on your 3D printer.
Action figures made on a 3D printer-some assembly required?
A 3D-Printer made this model of a house---it would make a fun dollhouse, too.
Innovating medical technology will let us use 3D printers for health purposes as well:
With a 3D printer, you could make custom-fit clothing.
If you don't have your own 3D printer, as long as you have the instructions in your file, you can upload it to an online service and have someone else 'print' it at a reasonable price and ship it to you. In the future, these 3D print shops may be seen at your local mall just like any other business.
And what about the future? What will 3D printers be used for in a few years?
- It is already being used for some airplane parts, and this will probably continue. These parts are lighter, making the plane more efficient to fly.
- In the health field, titanium bone implants, orthodontics, and artificial veins and arteries may be made using 3D printing
- 3D printers will probably be standard in schools from Kindergarten through college. They can be used to teach, creating models and copies to show students how things work
- There is some discussion whether it might be a better idea to send 3D printers to disaster sites so that needed items can be produced on-scene---especially for health care
- Items currently only available at museums could be copied, from historical clothing to animal bones, so that the 'cloned' exhibits can be brought around the country to people who can't travel to places such as the Smithsonian: http://www.3dprinter.net/3d-print-history-with-smithsonian-x-3d
- A discussion on how 3D printers could be used in the space program: http://www.forbes.com/sites/stevenkotler/2013/10/21/the-future-is-here-how-3d-printing-is-opening-the-door-to-space-colonization/2/