DFM Guide · Additive

Lattices.
Consolidation.
Print-native design.

Designing for additive manufacturing differs from machining. Build orientation, support structures, lattice infill, part consolidation enable geometries impossible to machine. Design native to the process.

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01 · Key principles

Key principles.

Build orientation

Critical decision

Build orientation affects surface finish, mechanical properties, support structures, and cost. Optimize before sending to print.

Support structures

Minimize them

Supports add cost and post-processing. Self-supporting overhangs ≤ 45° from vertical eliminate most supports.

Lattice infill

Reduce mass

Internal lattice structures reduce mass while maintaining stiffness. Common 30-70% lattice density.

Part consolidation

Multi-piece into one

Combine multi-piece assemblies into single printed part. Reduces fasteners, weight, assembly labor.

Hollow design

Drain holes

Hollow parts save material/time. Add drain holes for resin or powder removal.

Anisotropy

Z-direction weaker

Most processes weaker in Z (between layers). Orient with critical loads in XY plane.

FAQ

When does additive beat CNC?

For complex internal geometry impossible to machine, lattice/topology-optimized parts, low-volume custom parts. CNC wins for simple geometry, tight tolerance, production volumes.

Process selection?

SLA for fine detail prototypes, MJF for production nylon, DMLS for metal, FDM for large parts and aerospace polymers. Each has trade-offs.

Tolerance achievable?

SLA ±0.1 mm, SLS/MJF ±0.2 mm, DMLS ±0.2 mm. Post-machining critical features achieves ±0.025 mm CNC tolerance.

Cost vs CNC?

Per-part cost depends on volume and complexity. Additive economical for low volume; CNC for higher volume. Total geometry advantage often justifies additive premium for specific parts.

Materials available?

Photopolymer (SLA), nylon PA12 (SLS/MJF), titanium/Inconel/aluminum (DMLS), Ultem 9085 aerospace (FDM), thermoplastic blends. Material selection narrower than CNC.

Post-processing?

Support removal, bead blast, sometimes vapor smoothing or paint. CNC machining for tight-tolerance features. Heat treatment for metal additive.