Question: how does a 3d printer work, it doesnt make any sense?

Edward Taylor answered on 11 Mar 2013:

I think the easiest way to explain it is to imagine how we would do it by hand. Please do not try this at home though (or school), it would take a lot of paper and a long long time!

If you took a big stack of paper, cut out an identical square from each piece of paper and stuck the squares on top of one another, your glued stack of squares would get thicker and thicker until you would eventually get a cube shape that you could hold.

Now what if instead, you again cut squares out of the paper but with each piece of paper you cut out a slightly smaller square? When you glue them together this time, as the pieces of paper are stacked on top of one another and glued together, each layer will get smaller and smaller and so you will get a pyramid shape (with the largest square you cut out at the bottom and the smallest at the top). So by very slightly changing the shape we cut out of each piece of paper, the object that is made when we glue it all together completely changes.

This is pretty much the idea behind a 3D printer!
The printer software first takes your 3D drawing which you draw on a computer, and chops it into hundreds of layers. Each layer is like one piece of paper in our example above, and the software decides what shape that layer needs to be (usually more complex than a square!). Instead of cutting the shape out of paper, what the printer does is draw each shape with a thin layer of melted plastic which then cools to become a solid thin layer of plastic. Just like we stacked lots of bits of paper on top of one another, the printer stacks lots of layers of plastic until a complete object is made.

Take a look at this example http://www.youtube.com/watch?v=B6B8WgTOv_A
It shows a chess piece being made. Not quite as yummy as Nicola’s example unfortunately!