3D Printing (Additive Manufacturing)

3D printing (additive manufacturing) builds parts layer by layer from digital models, enabling complex geometries, rapid iteration, and cost‑effective low to medium volumes.

Overview

3D printing, or additive manufacturing, creates parts by depositing or fusing material layer by layer from a CAD model, rather than cutting from solid stock or using molds. It excels at complex internal channels, organic shapes, lattice structures, and rapid design changes without tooling. Lead times are short, setup costs are low, and each part can be unique at minimal extra cost.

Use 3D printing for prototypes, fixtures, custom or low-volume end-use parts, and designs that are difficult or impossible to produce subtractively. Plastic 3D printing covers concept models, functional housings, clips, and fixtures. Metal 3D printing targets high-value components like lightweight brackets, heat exchangers, and tooling inserts with conformal cooling. Composites 3D printing adds continuous or chopped fibers for high stiffness and strength at low weight. Tradeoffs include rougher as-printed surfaces, looser tolerances than precision machining, support-removal constraints, and part size limits by machine envelope. Post-processing such as machining, heat treatment, or coating is common when tight tolerances or critical surfaces are required.

Common Materials

  • PLA
  • ABS
  • Nylon 12 (PA12)
  • AlSi10Mg aluminum
  • 17-4 PH stainless steel
  • Carbon-fiber reinforced nylon

Tolerances

±0.005" to ±0.010" on critical features, depending on process, size, and orientation

Applications

  • Functional prototypes and concept models
  • Custom brackets and lightweight structural mounts
  • Jigs, fixtures, and assembly aids
  • Conformal-cooled tooling inserts and molds
  • Heat exchangers and fluid manifolds with internal channels
  • Patient-specific medical models and guides

When to Choose 3D Printing (Additive Manufacturing)

Choose 3D printing when you need complex geometry, rapid iteration, or customization without paying for tooling. It fits prototypes and low to medium production volumes, especially for lightweight, topology-optimized, or highly integrated parts. It also works well when consolidating assemblies into single printed components reduces labor and tolerance stack-ups.

vs CNC machining

Choose 3D printing when part geometry includes internal channels, lattices, deep cavities, or organic shapes that are hard or impossible to tool. It is also advantageous when you need many design iterations or custom variants without new setups and fixturing.

vs Injection molding

Choose 3D printing for low to medium quantities where mold cost and lead time are not justified. It is ideal for validating designs, bridge production before tooling, and producing variants or custom features that would require multiple mold revisions.

vs Die casting

Choose 3D printing when you need complex, lightweight metal parts in moderate quantities without investing in dies. It is especially useful for highly optimized brackets, conformal-cooled inserts, and development parts before committing to casting tooling.

vs Sheet metal fabrication

Choose 3D printing when the design needs 3D complexity, integrated features, or enclosed volumes that can’t be formed from flat stock. It can reduce part count by combining brackets, stiffeners, and hardware into a single integrated component.

vs Urethane casting (vacuum casting)

Choose 3D printing when you need faster turnaround, frequent design changes, or material options beyond castable urethanes. It avoids silicone mold fabrication and is better for intricate details or internal structures that would trap molds.

Design Considerations

  • Orient parts to balance surface quality, support volume, and mechanical properties; specify critical faces that may need post-machining
  • Design with self-supporting angles (typically ≥45°) and avoid large unsupported overhangs to reduce supports and post-processing cost
  • Use uniform wall thickness where possible and avoid very thin walls below process guidelines to prevent warping and incomplete fusion
  • Add generous fillets at internal corners and stress concentrations, especially in load-bearing features and lattice transitions
  • Include chamfers, tabs, or access features to aid support removal, cleaning, and inspection
  • Clearly call out functional tolerances and critical dimensions so the shop can plan post-processing and inspection steps accurately