FDM

Fused Deposition Modeling (FDM) has become one of the leading 3D printing methods for prototyping and low-volume manufacturing.

Material Selection

The first step in the FDM process is selecting the appropriate thermoplastic material. Common choices include ABS, PLA, PETG, and high-performance polymers such as Nylon and Polycarbonate. These materials are available in a range of colors and properties, allowing for customization based on the part’s requirements.

Printing the Part

The 3D printer heats the selected filament to its melting point, extruding it through the nozzle onto the build platform. Each layer of material bonds with the previous one, forming the part. This process continues until the entire part is completed.

Cooling and Solidifying

Once the part is printed, it cools and solidifies, assuming its final shape. Depending on the complexity of the design, additional support structures may be added to ensure stability during printing and are removed afterward.

Post-Processing

Once the part is printed, post-processing might be necessary to eliminate support structures and improve the surface finish. This can include sanding, painting, or applying coatings to improve the part’s appearance and functionality.

What Are the Challenges in FDM?

FDM offers numerous benefits, it does come with a set of challenges that can affect the quality and speed of production.

Limited Material Properties

While FDM supports a variety of materials, they may not be suitable for every application. Thermoplastics, although strong and durable, may not meet the stringent material requirements needed for industries like aerospace, where high-temperature resistance or extreme strength is needed. 

Layer Adhesion Issues

One common challenge in FDM is ensuring strong adhesion between layers. If the layers do not bond properly, the part may be prone to delamination or failure under stress. This issue is particularly prevalent in complex geometries or when using certain materials. Adjusting the print settings, such as nozzle temperature and print speed, can help mitigate these issues.

Surface Finish

While FDM parts are functional, the surface finish often requires post-processing to meet aesthetic standards. The layer-by-layer construction process leaves visible lines on the surface, which may not be acceptable for all applications. Sanding, smoothing, or coating can address this challenge, but it adds time and cost to the production process.

Build Size and Resolution

FDM machines are often limited in the size of parts they can produce. Large parts may need to be printed in sections and then assembled, adding complexity to the project. Additionally, the resolution of the printer, determined by the nozzle size and layer thickness, may not achieve the fine detail required for certain designs.

Warping and Shrinkage

As the thermoplastic material cools, it can shrink or warp, particularly for larger parts. This can lead to dimensional inaccuracies and cause the part to become misshapen. To mitigate this, proper bed adhesion, temperature control, and design modifications may be necessary.