Composites 3D Printing

Composites 3D printing builds fiber‑reinforced polymer parts with high strength‑to‑weight, directional stiffness, and complex geometries at low to medium volumes.

Overview

Composites 3D printing produces parts by depositing a thermoplastic matrix reinforced with chopped or continuous fibers, typically carbon, glass, or Kevlar. Processes like Continuous Fiber FDM and Chopped Fiber Infusion Printing align reinforcement along load paths, giving much higher stiffness and strength than unfilled plastics at a fraction of metal weight.

This process makes sense for low to medium volumes where you need lightweight, strong, and corrosion‑resistant parts without tooling costs. It shines for jigs, fixtures, robotic end-of-arm tooling, brackets, and housings that would be overkill in machined metal. Tradeoffs include FDM‑like surface finish, limited heat resistance compared with metals, and anisotropic properties that depend heavily on fiber orientation and layer direction. Critical features may still need light post‑machining. If you design with fiber paths and print orientation in mind, composites 3D printing can replace aluminum for many structural parts while cutting lead time and part weight dramatically.

Common Materials

  • Nylon with chopped carbon fiber
  • Nylon with glass fiber
  • Onyx (nylon with micro carbon fiber)
  • Nylon with continuous carbon fiber
  • Nylon with Kevlar fiber
  • PETG with carbon fiber

Tolerances

±0.008" to ±0.015" on most features; tighter with post‑machining of critical surfaces

Applications

  • Robot end-of-arm tooling
  • Assembly jigs and inspection fixtures
  • Lightweight structural brackets and mounts
  • Drone frames and UAV structures
  • Motorsport brackets and pedal components
  • Replacement aluminum tooling and nests

When to Choose Composites 3D Printing

Choose composites 3D printing when you need high strength‑to‑weight, directional stiffness, and moderate temperatures, without committing to tooling. It fits low to medium production volumes, quick-turn functional prototypes, and end-use parts where FDM-level finish is acceptable and geometry benefits from printed, fiber-reinforced construction. It is especially effective when you can align fibers along known load paths.

vs Plastic 3D Printing

Pick composites 3D printing instead of standard plastic 3D printing when parts see real structural loads or need stiffness closer to aluminum. It justifies the higher part cost when you can exploit fiber orientation for strength-critical features while still accepting additive-level surface finish and tolerances.

vs Metal 3D Printing

Choose composites 3D printing over metal 3D printing when operating temperatures and loads are within high-performance polymer limits and weight and cost are critical. You avoid expensive metal powders, slower builds, and extensive post-processing, while still getting strong, lightweight structural parts for many tooling, robotic, and fixture applications.

vs CNC Machining

Use composites 3D printing instead of CNC machining when geometry is complex, quantities are low, or you want to consolidate multi-part metal assemblies into one lightweight printed structure. You trade off tight tolerances and machined finishes for faster lead times, no fixturing, and easy iteration, especially for fixtures and EOAT.

vs Injection Molding

Select composites 3D printing over injection molding for low to medium volumes where mold cost and lead time are not justified. It lets you iterate design and fiber reinforcement freely, accept slightly higher per-part cost, and still achieve strong, repeatable parts without committing to a fixed tool.

Design Considerations

  • Orient the part so primary load paths align with continuous fiber directions and strongest layer orientations
  • Use thicker walls and ribbing instead of thin features; target minimum wall thickness of 2–3 nozzle diameters for structural regions
  • Avoid tiny holes, sharp internal corners, and thin tabs; size features to at least 2–3 layer heights and allow fillets for fiber steering
  • Explicitly call out critical dimensions and surfaces that may need secondary machining, and include extra stock where required
  • Minimize unsupported overhangs and deep internal channels that trap support material or prevent continuous fiber routing
  • Provide clear load cases and usage details in RFQs so the shop can choose appropriate fiber type, volume fraction, and layup strategy