

Human: What is a 3D printer

Assistant: A 3D printer is an amazing technology that lets us make virtually any physical object.  
We start with a computer file.  It could be an image, or a very precise set of instructions that a 3D printer understands.  We put these files on a computer and send it to the printer.  The printer reads these files, and lays down layers of material, one at a time, to create the 3D object.  
Here are a few ways people use 3D printers.

Human: How expensive are they?

Assistant: 
The really cool thing about 3D printers is that the cost comes down very rapidly.  The price started at $100,000 and has dropped to $3,000.  You can actually build a 3D printer yourself!  You can buy plans, or a kit, and the hardware only costs a few hundred dollars.  The only thing you need to do is download a free program to write the “printer” files. 
3D printers can cost anywhere from $1,000-$5,000, depending on the quality of the printer and what type of materials you want to use.  For example, a printer capable of printing with an aluminum alloy would cost much more than a printer capable of using plastic filament.  