Plastic 3D Printing

Plastic 3D printing builds polymer parts layer-by-layer from CAD, enabling complex geometries and fast iteration with tradeoffs in anisotropy and surface finish.

Overview

Plastic 3D printing produces polymer parts directly from CAD by depositing, curing, or fusing material in layers (FDM, SLA/DLP, SLS/MJF, PolyJet). It excels at complex internal features, rapid design iteration, and low-volume production without tooling.

Choose it for prototypes, form/fit checks, functional test parts, jigs/fixtures, and short-run end-use components where geometry drives value more than tight tolerances or pristine cosmetics. Lead times are typically days, and design changes cost little.

Tradeoffs: mechanical properties are process- and orientation-dependent (layer lines, anisotropy), surfaces may require post-processing, and tight mating features often need secondary machining. Material options range from commodity plastics to engineering nylons and elastomers, but high heat, UV, and chemical exposure must be validated per material and process.

Common Materials

  • ABS
  • PLA
  • PETG
  • Nylon 12
  • TPU
  • Polycarbonate

Tolerances

±0.005" to ±0.020"

Applications

  • Prototype housings and enclosures
  • Snap-fit and clip validation parts
  • Assembly fixtures and drill guides
  • Ducts, manifolds, and complex airflow parts
  • Low-volume custom brackets and mounts
  • Visual models and ergonomic mockups

When to Choose Plastic 3D Printing

Choose plastic 3D printing for low volumes (1–500+), frequent design changes, and parts with complex geometry, internal channels, or consolidated assemblies. It fits best when moderate tolerances and some post-processing are acceptable and you want parts fast without tooling.

vs Metal 3D Printing

Choose plastic 3D printing when loads, temperatures, and wear demands can be met with polymers and you want faster turns and lower part cost. It’s also the better fit for ergonomic, enclosure, and fixture-style parts where weight and corrosion resistance matter more than metal strength.

vs Composites 3D Printing

Choose plastic 3D printing when you need isotropic-enough performance for the application without fiber reinforcement complexity. It’s typically easier to quote, finish, and assemble, and it supports finer cosmetic surfaces (SLA/PolyJet) or robust nylon production parts (SLS/MJF).

vs Injection Molding

Choose plastic 3D printing when you need parts this week, volumes are low, or the design isn’t frozen. It avoids mold cost and enables geometry (internal lattices, conformal ducts) that would drive complex tooling and long lead times.

vs CNC Machining (Plastics)

Choose plastic 3D printing when the part has internal cavities, undercuts, or organic shapes that are difficult or wasteful to machine. It’s also cost-effective for one-offs and iterations, while machining is usually better for tight bores, flatness, and precise interfaces.

vs Urethane Casting

Choose plastic 3D printing when you want direct-from-CAD parts without master patterns or silicone tooling. It also works better for complex internal passages and frequent revisions; casting wins more often on uniform cosmetics across small batches.

Design Considerations

  • Orient the part so critical load paths aren’t relying on inter-layer strength; call out build orientation if it matters
  • Add clearance for mating features and fasteners (typically 0.2–0.5 mm) and plan to ream/face critical holes
  • Avoid long, thin unsupported walls; add ribs, gussets, or minimum wall thickness per process (SLA can be thin, FDM needs thicker)
  • Design for support removal and finishing: minimize deep pockets and trapped volumes where supports or powder can’t escape
  • Specify surface finish expectations and post-processing (bead blast, dye, vapor smooth, machining) on the drawing/PO
  • Provide a clear tolerance scheme: only tighten what’s functional and mark features intended for secondary machining