If you don't know, a 3D printer is a machine that creates a 3D object. It's print head is able to move in 3 directions, side to side plus up and down. Any object can be thought of as being made up of many, many thin layers. A 3D printer prints each of those layers one at a time from the bottom of the object to the top. Of course, it isn't using ink but rather some material that can be extruded in a liquid form that quickly hardens. The one I saw used a type of plastic.
Think of a brick house. You lay the first row of bricks around the foundation. Then you add row after row of bricks until you finally have a house. If your bricklayer were a 3D printer, then each layer of bricks would be one pass of the printer head. Still not clear? Don't worry, lots of folks have a hard time getting their head around this one. I think the big problem is calling them 3D printers. They should have borrowed the name from Star Trek and called them replicators! Watch the movie and hopefully it will make more sense.
Hod Lipson and Evan Malone at Cornell University have developed a 3D printer that you can build, if you are handy, for around $2400. It's open source and the plans are free. Their hope is to get a lot of people working on this project and get the price down and the quality up. Imagine if you will, anything you can design in a CAD program could be reproduced as a 3D object.
NewScientistTech Article: "Desktop fabricator may kick-start home revolution"
Popular Mechanics Article:
[Image: (Hod Lipson / Evan Malone) from"Desktop fabricator may kick-start home revolution." NewScientistTech. 09 Jan 2007. NewScientistTech. 26 Oct 2007