Fused deposition modeling, also known as FDM or 3D printing, is an additive manufacturing process. FDM works additively, by laying down material layer by layer to ultimately form the desired shape. Thermoplastic filaments are the most common materials for FDM, and are generally unwound from a coil to supply the machine producing the part. 3D printings is popular for modeling, prototyping, and, in some instances, volume production applications.
Fused deposition modeling starts STL (stereolithography) files, which are used to mathematically slice and orient the model for layer by layer building. The model or part is produced by extruding small beads of material (from the above-mentioned coil) to form layers. The extrusion nozzle is heated past the glass transition temperature of the thermoplastic material; the material hardens immediately after extrusion from the 3D printer’s nozzle. Typically, worm gear drives or other similar devices are used to push the material filaments through the nozzle at a controlled rate. Parts are built from the bottom up, one layer at a time. In most 3D printing devices, the extrusion nozzle is moved horizontally and vertically by CNC controlled stepper and servo motors.. The nozzle’s tool-path is guided by CAM software, using X-Y-Z rectilinear designs. The FDM process may use multiple materials to achieve different goals—for example, one material may be used to build up the model itself, while another material may be used to create soluble (and easily removable) support structures, as needed. Multiple colors of the same material can also be used in the same model or part. Numerous thermoplastic materials, such as ABS, PLA, polystyrene, polycarbonate, Ultem, and others are used for fused deposition modeling. Each offers unique advantages and disadvantages, and the correct material for a given application can be determined by balancing the necessary strength and temperature properties.
3D Printing Applications
Fused deposition modeling is commonly used for prototyping and rapid manufacturing. In short runs, FDM can be a fast and inexpensive a