SLS allows stacking parts three-dimensionally in the build volume without supports; orientation and nesting strategy directly control cost per part and build efficiency.
Because SLS uses a powder bed that is self-supporting, parts can be stacked in the Z direction, nested inside each other, and placed at any orientation: with no support material between them. This transforms orientation from a single-part decision into a batch economics problem. Machine utilisation (volume fill ratio) directly impacts cost per part: a 40% volume fill halves costs vs a 20% fill. Z-height governs total build time; minimising max Z of the batch reduces time.
Orient elongated parts horizontally to reduce Z-height. Nest smaller parts in the cavities or shadow of larger parts. Keep the total Z below 200 mm if possible for a faster build. Reserve vertical stacking for small high-count parts (e.g. clips, brackets). Use slicer nesting tools (Materialise Magics, EOS RP Tools): manual nesting loses ≥ 15% efficiency.
Anisotropy is nearly negligible in SLS (98% XY/Z) but not zero: for critical tensile parts still check load path alignment. Minimum clearance of 0.4–0.6 mm between parts is mandatory for powder flowout. Dense nests near the powder refresh cylinder may have more thermal variance: test with a dummy nest first.
Related terms: Support strategy (SLS vs DMLS), Build orientation decision, Self-supporting design (minimising supports)
| Theme | orientation |
|---|---|
| Also called | part nesting, build volume efficiency, SLS batch orientation |
| Source | tech/dmls.md, concepts/additive-manufacturing.md |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert