3D printing involves building a three dimensional object from a computer aided design model by successively adding materials layer by layer on top of each other using a 3D printing machine. Within the last decade 3D printing usage has increased dramatically that this technique is now used for industrial applications such as building apartments and making prototypes for machines. The most commonly used 3D printing process is a material extrusion technique called Fused Deposition Modelling (FDM). Other techniques used for 3D printing are Stereo lithography and Selective Laser Sintering. The Fused Deposition Modelling is however the less expensive of the three hence its popularity. 3D printers have the advantage of producing very complex shapes of various sizes and a requirement for successful 3D printing is a digital 3D model or a Computer Aided Design or CAD file.
3D printing machines operate with 3D digital models or CAD files. The models are created with a Computer Aided Design package using a 3D scanner or a plain digital camera and photogrammetry software. The printed models can be created with CAD contain errors that can easily be corrected before printing. 3D scanning is the process of collecting digital data on the shape and appearance of a real object, creating a digital model based on it..The CAD models can be saved in the stereo lithography file format, a CAD file format for additive manufacturing. However a new file format was created in 2011 to replace the STL file format since it was not suitable for additive manufacturing. The Additive Manufacturing File Format which replaces the Stereo lithography file format stores information using curved triangulations. Before printing a 3D model from an STL file it needs.to be examined for errors. Such errors include holes, self intersections, face normals, manifold errors, noise shells. A step in the STL generation fixes such problems in the original model. Once completed the STL file will be processed by a software known as slicer which converts the model into a series of thin layers and produces a G- code file containing a series of instructions for a specific type of 3D printer i.e the FDM printers.
3D printing is now widely used in the manufacturing industry to build apartments, fabricate tools, build model prototype for tools and machine parts. They widely used in the medical industry for surgical tools,reconstructive surgery, medical implants, virtual planning of surgery etc.
3D printing is used in the clothing industry to print out new clothing designs as protoypes for testing.
They are now being used to manufacture spare parts for air craft. Firearms are now being manufactured using 3D printers.
3D printing is now used in the food industry to create a wide variety of foods such as pasta, chocolate, candy, crackers and pizza.