The basic concept behind all 3-D printers is the same. 3-dimensional CAD drawings are sliced into layers ranging from approximately 0.09 to 0.25 millimeters thick depending on the machine being used. Each slice represents a single layer of the constructed object. Different printers use different materials and different binding processes, but generally a powder of ceramic, nylon, or even metal is used as the base material and fused together into the pattern for the layer currently being created. After the completion of a layer, the machine moves on to the next layer until it is completed. In other words, they work in layer-by-layer. Depending on the printer or service used, there may be software that does this slicing automatically or the user may be responsible for creating each layer (generally speaking, the process is automated in higher end models and manually performed for open source or less expensive printers).
There are 3 main steps in 3D printing.
The first step is the preparation just before printing, when you design a 3D file of the object you want to print. This 3D file can be created using CAD software , with a 3D scanner or simply downloaded from an online marketplace. Once you have checked that your 3D file is ready to be printed , you can proceed to the second step.
The second step is the actual printing process. First, you need to choose which material will best achieve the specific properties required for your object. The variety of materials used in 3D printing is very broad. It includes plastics, ceramics, resins, metals, sand, textiles, biomaterials, glass, food and even lunar dust! Most of these materials also allow for plenty of finishing options that enable you to achieve the precise design result you had in mind, and some others, like glass for example, are still being developed as 3D printing material and are not easily accessible yet.
The third step is the finishing process. This step requires specific skills and materials. When the object is first printed, often it cannot be directly used or delivered until it has been sanded, lacquered or painted to complete it as intended.