FDM / FFF 3D Printing
‘Fused Deposition Modeling’ (FDM) or ‘Fused Filament Fabrication’ (FFF) is mainly used for functional testing and early stage prototypes. Developed in the late 1980’s, FDM is one of the oldest 3D printing technologies. The term FDM was created and copyrighted by Stratasys, the term FFF was created through the open source project RepRap. Both are essentially the same technology and function by melting plastic and extruding it in a pattern, layer-by-layer on a variable height build platform.
In the first step of FDM, specialty software digitally slices the 3D model into slices – these slices are the individual patterns which make up the layers. The thickness of the slices depends on the settings, we typically print between 100 and 200 µm.
Once the model is sliced, the data is transferred to the 3D printer. The print head follows the slice pattern and extrudes the melted plastic onto the build platform. The plastic cools down immediately after extrusion and solidifies. This process is repeated for each layer, until the model is completed.
FDM uses relatively cheap material but still has two disadvantages: first, the melted plastic comes from a round nozzle. Hence, the model is made of stacked round strings and the resulting surfaces is not perfectly flat. Second, for overhanging parts, support structures need to be added. Those increase the material consumption and generally leave an imperfection where they meet the part’s surface.
Functional early stage prototypes
FDM 3D printed parts are of high mechanic strength, but lack dimensional accuracy and surface quality of other technologies (such as Laser Sintering or Polyjet). However, due to material characteristics, which are close to injection molded plastics and the fast and economic production, it is a great technology for initial prototype testing.
Fixtures / Mechanical Parts
The high mechanic strength enable FDM prints to be used as fixtures or mechanic parts. When designing your parts for such a purpose, consider the anisotropy of the technology and tolerances. If you have certain preferences for print orientation (e.g. to counteract the anisotropy), infill, layer height or wall thickness, please get in touch with us.
- Low cost
- Parts mechanically strong
- Light but strong parts, due to stabilizing infill
- Loose tolerances
- Limitations in geometric complexity
- Rough surface finish
- Warping effects quite common
- Solid bodies in the digital model are not printed solid, but with a stabilizing structure, called ‘infill’. This structures fills approximately 20% of the model. Solid models can cause strong warping effects and increase the printing time by magnitudes.
New materials for FDM/FFF printing are released almost weekly. The most used materials are ABS and PLA. They are available in a variety of colors and also as compounds with special characteristics, e.g. metallic or glow in the dark effects.
New classes of materials include flexible, heat resistant, chemical resistant versions of PLA or ABS as well as materials simulating the characteristics of common polymers like PA,PC or PET.
Here at 3Faktur, we offer for FDM 3D Printing only engineering polymers, such as PA6 and ABS.
Acrylonitrile butadiene styrene (ABS)
ABS is relatively heat resistant and rigid with some flexibility in thin structures. ABS is very commonly used in industry, being used for everything from car parts to Lego toys.
PA6/PA66 (FDM Nylon)
ABS can be sanded and/or bead blasted on request. PA6/PA66 is very abrasion resistant and cannot be surface-treated after printing.
Mr. S. Scott Scrump was looking for a birthday present for his daughter – she asked him to get her a green plastic frog. Since he couldn’t find the right present, he tried to think of a way to produce it. His idea was, to basically reverse the milling process, and rather than removing material from a block, building up an object from scratch.
His wife Lisa helped him with the development and the technology was patented in 1992. At the same time, he developed the first commercial FDM printer and launched his company Stratasys – today one of the leading 3D printer manufacturers in the world.
In 2007, members of the open source project RepRap created their first functioning 3D printer. In order to avoid a conflict over the technology name, they introduced the term FFF. In 2009 most of the original patents expired, which opened the market to a broader customer base. One of the best known examples is MakerBot, which was one of the first companies to offer desktop 3D printers. MakerBot was acquired by Stratasys in 2013.
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