3D printing (or more specifically Fused Deposition Modeling) is an additive manufacturing process through which parts are created by slowly building up material, layer by layer, into a desired shape. There are multiple types of 3D printing currently in use, however FDM is the most common. A spool of plastic with a uniform, circular cross section called FILAMENT (we use E-Sun brand filament as shown here, but there are endless possibilities to choose from) is fed through a heated nozzle via what is appropriately named, an EXTRUDER. The molten plastic is then deposited onto the Build Platform in precise, uniform layers (usually between .1-.3mm) that are slowly built up to create a solid part.
A printed part begins its life as a 3D CAD model. Once a 3D model of the part has been created, it is saved as a STL (stereolithography) file and input into a slicing software. Think of the slicing software as a sort of electronic knife, which slices the model into extremely thin wafers from bottom to top. These wafers are what become the LAYERS of the print, which are built up one by one to produce the finished part. The thickness of these layers, as well as seemingly endless other settings, can be manipulated within the slicing software.
One of the most important settings on a print (and one we feel is worthy of its own paragraph), is call INFILL. This is the setting that determines what percentage of the INTERIOR of a model will be solid. This is one of the biggest advantages in additive manufacturing, it allows for the creation of a semi-solid core that can be varied based on the intended use of the part. While something like a cable guide may need to be solid throughout (100% infill), if we were simply building a prototype part for test fitment purposes only it may be perfectly acceptable to have an infill of only 25% or lower. This simple change will substantially decrease print time, plastic usage, and still produce a part that is adequate in strength.
After a print has been sliced by the slicing software, it is saved as a G CODE file. G code is an accepted industry standard that drives everything from CNC machines to the printer that is making our parts. It is essentially a series of commands that instructs the printer on how much plastic to extrude, where on the Cartesian plane to move to, how fast to make each move, what temperature to heat the extruder to, etc. The G code file is uploaded to the printer, set to run, and like magic a part is formed!