How Does a 3D Printer Work?

Most small 3D printers used in the home or at a school use a method called fused deposition modeling (FDM). The process is similar to that of a glue gun, in that you start with a solid material. Once it is heated, it melts and can be extruded.  When it cools, it fuses together and turns back to a solid again. This type of  plastic is a thermoplastic.The material in an FDM 3D pinter is called filament which is fed into the top of the print head, the mechanism that controls where the filament comes out. To make the layers, the print head moves back and forth and side to side in an X, Y direction. The print bed moves down in the Z direction as the object is created layer by layer. This allows the object to be build upwards into the third dimension. A computer program tells the printer what pattern to print, which gives the printer its X,Y and Z coordinates.The printer bed is the flat platform on which the printed object is formed. Some printers use heated print beds so that the warm molten plastic hitting a cold surface doesn’t warp the object. Printing with a raft, or extra layers of plastic under your object ,can yield a better quality print, however keep in mind that it makes it more difficult to get your object off the bed.There are two main types of plastic filament used with low-cost 3D printers: ABS (Acrylonitrile butadiene styrene) and PLA (Polylactide). ABS melts at a higher temperature than PLA. PLA is thought be safer for use with children because it is made with cornstarch or sugar. Some printers can print in both ABS and PLA. A basic roll of filament is inexpensive and costs around $25.Most home 3D printers have a small print size due to having a small print bed and they only print one color.  There are other types of printers that can be found at service bureaus or in industrial settings that produce higher quality products, larger print sizes and can print in full color. These printers can also print materials other than plastic such as metal, ceramic and glass.