Idaho-based Continuous Composites has been awarded a Phase II Small Business Innovation Research (SBIR) contract from the US Navy to push its Continuous Fiber 3D Printing (CF3D) process toward a genuinely strange goal: printing the wiring of a drone into the same structure that holds it together. Instead of a fiberglass or carbon-fiber airframe with a separate wiring harness routed and secured inside it, the Navy wants a single printed part where copper conductors and fiber-optic lines are laid down as the composite structure itself is built.

The award follows a completed Phase I effort in which Continuous Composites demonstrated the core idea was even possible: co-printing conductive elements — copper wiring and fiber optics — inside fiberglass-reinforced composite panels, with what the company describes as minimal impact on the panels' mechanical performance. That's the hard part of this kind of work. It's one thing to route a wire through a printed cavity after the fact; it's another to lay conductive material into a structural composite mid-print and have the part still hold load the way an aerospace engineer expects it to.

What CF3D Actually Does

Continuous Fiber 3D Printing is not filament-based FDM. The process pulls continuous fiber — glass or carbon — through a robotically guided printhead and cures it in free space as it's laid down, building up load-bearing structures without the layer-by-layer scaffolding constraints of conventional composite fabrication. Because the print path is continuous and the head can be directed almost anywhere in 3D space, it opens the door to embedding other continuous elements alongside the structural fiber in the same pass — which is exactly what the Navy contract is asking the company to expand.

Phase I proved the concept at panel scale. Phase II, a 30-month research and development effort with a one-year option for a system-level demonstration, is aimed at scaling that up: higher-capacity conductive pathways routed through actual load-bearing UAV components, not just test panels, plus a stated goal of rapid field-replaceable parts. Read between the lines and the target application is clear — a drone structure where power and data lines are baked into the airframe rather than harnessed separately, and where a damaged structural section can be swapped in the field without also re-running wiring.

"By embedding electrical pathways into load-bearing composite components, we're enabling a new class of multifunctional UAV systems designed for real-world operational environments," said Continuous Composites CEO Steve Starner in the company's announcement. That's a fair summary of where a chunk of the composites-manufacturing world has been heading for a few years now — treating additive manufacturing not as a way to make a shape, but as a way to make a part that already contains its own systems.

Why the Navy Cares About Wire Harnesses

Wiring harnesses are a disproportionately annoying part of building and maintaining small aircraft. They're hand-assembled, they add weight and volume that has to be routed around structural members, they're a common failure point from chafing and vibration, and when something breaks, diagnosing and repairing a buried harness is often more labor than the structural repair around it. For a UAV program, all of that gets worse under field conditions, where a technician may need to swap a damaged wing or fuselage section quickly and without a depot-level rework.

Eliminating a discrete harness by printing conductors directly into the load path doesn't just save assembly steps — it removes an entire category of connector and routing failure, and it means a "field-replaceable part" can genuinely be a single printed unit rather than a structural piece plus a wiring sub-assembly that has to be re-terminated. That's the practical case for a Phase II SBIR: Phase I showed the physics works at small scale, and the Navy is now paying to find out whether it works at the scale and duty cycle an actual UAV program needs.

What It Means for Makers

None of this is coming to a desktop printer anytime soon — CF3D uses proprietary continuous-fiber hardware and Continuous Composites' own robotic printheads, not anything resembling a consumer FDM or resin setup. But the direction is worth watching for anyone following where composite and electronics-embedding printing is headed. The maker and prosumer world has already been experimenting with embedded-trace printing (conductive filament traces, dropped-in wire during a pause, conductive ink deposited mid-print) for years on a hobbyist scale. What the Navy is funding here is essentially the aerospace-grade, load-bearing version of the same idea, with continuous fiber reinforcement doing the structural work instead of a printed thermoplastic shell. The signal for makers is less "buy this machine" and more "this technique is maturing." As embedded-conductor printing gets validated on load-bearing aerospace parts under a government contract, the manufacturing knowledge — how to route conductors without compromising fiber alignment, how to manage curing around embedded copper, how to keep field-replaceable connectors accessible — tends to filter down into commercial tooling and eventually into more accessible hardware. If you build multirotor frames, fixed-wing UAVs, or anything else where wiring harnesses are a chronic pain point, this is the kind of program to keep an eye on over the next few years, even if the equipment itself stays well out of garage-shop price range.

Bottom Line

Continuous Composites has 30 months, plus a one-year option, to prove that copper wiring and fiber optics can be printed directly into load-bearing UAV structures at a scale useful to the Navy — not just in test panels. Phase I already showed the basic co-printing concept works without gutting mechanical performance. Phase II is the harder test: whether a printed airframe section can carry both structural load and its own electrical system, and still be something a field technician can swap out in a hurry.

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