FDM: Fused Deposition Modelling Versus SLA: Stereolithography
3D printers that run on FDM Technology build parts layer-by-layer from the bottom up by heating and extruding thermoplastic filament. The process is simple:
- Pre-processing: Build-preparation software slices and positions a 3D CAD file and calculates a path to extrude thermoplastic and any necessary support material.
- Production: The 3D printer heats the thermoplastic to a semi-liquid state and deposits it in ultra-fine beads along the extrusion path. Where support or buffering is needed, the 3D printer deposits a removable material that acts as scaffolding.
- Post-processing: The user breaks away support material or dissolves it in detergent and water, and the part is ready to use.
SLA printers consistently produce higher resolution objects and are more accurate than FDM printers. The reason: The resolution is primarily determined by the optical spot size either of the laser or the projector – and that is really small. Moreover, during printing less force is applied to the model. This way, the surface finish is much smoother. SLA prints show details a FDM printer could never produce.