The deliberate choice of internal geometry pattern and density for FDM/SLS parts, balancing mechanical performance, print time and material consumption: not a slicer default but a DfAM decision.
Infill pattern determines how internal struts transfer load to perimeter shells. Triangular infill at 30% density carries ~25% more load than rectilinear at the same density because triangles resolve shear into axial forces. Gyroid infill provides nearly isotropic stiffness in XY and Z: beneficial where load direction is unknown. Honeycomb offers high in-plane stiffness but weak peel strength.
Functional structural parts: use triangular or honeycomb at 30–50% density, with 4+ perimeters for surface hardness. Flexible hinges or dampers: use gyroid or concentric at 15–25%. Decorative or draft parts: rectilinear at 10–15% for speed. For critical load paths, consider solid perimeters plus sparse infill (20%) rather than uniform 50%: saves material without sacrificing surface strength.
High infill (> 50%) creates excessive internal heat during FDM, causing warping on large flat parts. Many slicers default to 15% rectilinear: always override this for load-bearing parts. Infill pattern alone cannot compensate for poor orientation; a well-oriented part with 20% triangular beats a badly oriented part with 80% grid.
Related terms: Lightweighting / Mass Reduction, Design for Minimal Material, Topology Optimization
| Theme | optimization |
|---|---|
| Also called | infill pattern, fill density, internal structure |
| Source | Wiki/concepts/dfam.md |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert