A DfAM principle that treats material as a cost to be minimized: using shells instead of solids, removing non-load-bearing volumes, and sizing features to functional minimums rather than convenient CAD defaults.
Unlike subtractive processes that start from a block and remove material, AM starts from nothing and adds material selectively. This makes over-design especially costly: every extra gram adds print time, material cost and post-processing. The principle demands that wall thickness equals the functional minimum (not 'round number'), hollow bodies use minimum shell + drainage, and ribs replace solid webs wherever buckling is not limiting.
Practical techniques: (1) replace a 10 mm solid wall with a 1.5 mm shell + internal rib grid; (2) set wall thickness as a multiple of nozzle diameter (FDM) or laser spot (SLS/DMLS); (3) use variable cross-section beams: thicker where bending moment peaks, tapering away. In SLS, reducing average cross-section also reduces cool-down time and residual stress gradient.
Designing to absolute minimum without safety factor risks brittle failure. In FDM, walls below 2 × nozzle diameter (< 0.8 mm for 0.4 mm nozzle) are unreliable. Minimize material but always respect the dfam.*. wall_thickness rules for the chosen technology. Minimum material in resin processes (SLA) can cause drainage vacuum lock: always pair with drainage holes.
Related terms: Lightweighting / Mass Reduction, Infill Strategy (DfAM Perspective), Topology Optimization
| Theme | optimization |
|---|---|
| Also called | material minimization, lean geometry, efficient material use |
| Source | Wiki/concepts/dfam.md |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert