Fused Deposition Modeling (FDM)
A fused deposition modeling machine melts a plastic filament and extrudes it through a nozzle. The melted material is laid down on the build platform, where it cools and solidifies. By laying down layer on layer the part is built.
Fused deposition modeling requires support structures which anchors the parts on the build platform and supports overhanging structures. Through the use of a second nozzle, the support structure can be built in a different material. Several parts can be produced at the same time as long as they are all anchored on the platform.
Advantages / disadvantages
Fused deposition modeling works with standard materials, for instance ABS or PC. Therefore, parts have good mechanical properties and are durable over time. Parts can be post-processed as any plastic part produced with conventional manufacturing.
Through the deposition of extruded material layer-by-layer, parts have an anisotropy in the z-direction (vertical direction), the surface has a step-structure and fine details cannot be realized.
- Prototypes are produced for form / fit and functional testing in standard materials by FDM
- Support parts (jigs, fixtures, helps) can be produced directly
- Small series parts down to one of a kind are built in standard materials by fused deposition modeling
Characteristics / restrictions
- Maximal build envelope: 914x610x914 mm3
- Minimum feature size: 0.178 mm
- Typical tolerance: +/-0.178 mm (can be improved through post-processing)
- Minimum layer thickness: 0.178 mm
Characteristics are only indicative, as there are different types of machines available.
Pre-build planning includes decisions regarding support structure and build strategy of each layer. Fused deposition modeling parts can be post-processed as any plastic part. Read more
The production of parts is planned in a build preparation software. One or several parts are loaded from digital 3D files (typically in the STL file format) and arranged on the build platform. Support structures are created. Further, the strategy how the nozzle is laying out the melted plastic in each layer can be determined, which impacts the final part characteristics.
- Remove supports: Parts are broken off the build platform. Often support structures are made of a water or base dissolvent material. They can be removed by placing the parts in a bath. Otherwise supports need to be removed mechanically.
- Post-machining: Parts might be post-machined in order to fulfil critical tolerances.
- Surface finish: Often parts need to be further processed to improve surface finish –by removing (e.g. polishing, grinding, peening) or by adding material (e.g. painting, coating).