FDM, fused deposition modeling, is an additive manufacturing process that creates three- dimensional objects by depositing plastic materials in layers. Unlike traditional subtractive manufacturing (machining) which removes material, additive manufacturing adds material through extruding thermoplastics. As a result, this reduces waste and allows businesses to produce parts faster and at a lower cost than traditional subtractive techniques. FDM printers are becoming very common in the workplace with desktop versions and commercial versions. The desktop printers are great for hobbyist and personal use. The commercial printers give the users more material options, larger build envelopes and higher quality parts with multiple layer thickness options. Cyb Llings uses Stratasys 400mc and 450mc FDM printers which are commercial grade printers to print parts for our customers.

The FDM process is best described by drawing a similarity to how a hot glue gun functions. A solid monofilament line of plastic is fed into a print head where it is melted and then extruded along a path on the build tray layer by layer following the part profile to build a part.

To prepare the print data, a CAD file is created by the engineer/designer for the desired part and is converted into a STL file format for the 3D printer software to read. The 3D printer software then slices the STL file into layers and creates sliced profiles used to create extrusion paths for the print heads to follow. This software used for the FDM printer provides options to change the fill the interior cavities on the part. The three options are sparse fill (honey comb), double density (honey comb with thicker walls) and a solid fill. Once the print data is prepared, the plastic filament line is fed into a heated print head then extruded out into the heated build chamber. The print head is mounted on the two axis (x-y plane) gantry systems that outline the part. The print tips can also be changed to switch the layer of thickness. The smaller the print head, the more finer features on a part and it provides a smoother surface finish. The build chamber is heated to stabilize the material as it is being printed, preventing warpage and delamination. The heated material is then placed on the build tray along the printing path that forms the contour of the part. The build tray moves in the z-axis and lowers as each layer is placed onto the part outlined. The amount of time it takes for each part to be built depends on a few things, fill volume, model complexity, print head size, model size, and the amount of support material required. There are two materials that are required for a part, the plastic filament and support material. The plastic filament has a variety of types of plastics (ABS-M30, ABS-M30i, PC-ABS, and ULTEM 9085). These materials are ideal for functional prototyping, manufacturing tools, end-use parts or concept models. Now, the support material is the foundation for the model and provides support for any cantilevered features. This support material is removed when the part is complete in the printer. There are two ways the support material can be removed, by breaking it away and/or dissolving it away in solvents.

The FDM additive manufacturing process creates high strength and durable parts, parts can withstand heat, it can be used in a variety of ways (functional parts, prototype parts or space claim models), it is typically cost-effective, and has a high turnaround rate compared to traditional manufacturing. The FDM process helps to make your ideas become reality.