The smallest geometric feature a given AM process can reliably reproduce, determined by nozzle diameter, laser spot size, vat resolution, or powder particle size.
FDM: min wall = 2× nozzle diameter (typically 0.8 mm with 0.4 mm nozzle). Min pin/post diameter ≈ 1.5–2 mm. SLA/DLP: min feature ~0.2–0.5 mm (laser spot / pixel size). SLS: min feature ~0.8–1.5 mm (particle size + laser spot). PolyJet: ~0.1 mm (16 µm layers).
Always check process capability table before designing features. FDM: avoid pins < 1.5 mm diameter; walls < 0.8 mm will under-extrude or not print. SLA: fine text embossed at ≥ 0.5 mm depth, ≥ 0.4 mm stroke width for reliable reproduction.
Features near minimum size often print with poor geometry or fail completely. Print and verify a feature size test coupon on the target machine before designing around minimum values. Add 20% margin to stated minimums for production reliability.
Related terms: DfAM (Design for Additive Manufacturing), Build Orientation, Lattice Structure, Hole Sizing for 3D Printing
| Field | engineering |
|---|---|
| Also called | minimum wall thickness, minimum printable feature, resolution limit |
| Source | EDi Brain: rules-core |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert