Fused Deposition Modeling (FDM) is the most widely used additive manufacturing process for desktop 3D printers. The process involves extruding a melted plastic from a computer-controlled nozzle, building a part layer by layer.

FDM 3D printers use a spool of filament as raw material. This filament is directed into the print head, where it is melted and deposited onto the incomplete part. In accordance with computer instructions, the print head moves along 3 axes in order to deposit material in the right place.

Because the material cools after it is deposited, further layers of material can be deposited on top of the existing layers, allowing for the creation of 3D shapes.

FDM is also known as Fused Filament Fabrication (FFF).

Advantages
  • Most affordable 3D printing process for plastic parts
  • Material options
  • Widely available
Disadvantages
  • Comparatively low resolution
  • Produces visible layer lines
Typical accuracy
  • ± 0.5% (desktop)
  • ± 0.15% (industrial)
Typical layer height
  • 50-400 microns

FDM Materials

Advantages
Disadvantages
Typical accuracy
Typical layer height

Stereolithography Materials

Advantages
Disadvantages
Typical accuracy
Typical layer height

SLS Materials

Advantages
Disadvantages
Typical accuracy
Typical layer height

SLM Materials