3D printing while airborne aboard a tiltrotor aircraft or during off-road manoeuvres in military vehicles is an irregular testing approach for new 3D printers. Yet, under these extreme conditions a US Navy developed expeditionary 3D printer rose to the challenge. I spoke with the project lead to learn more.
The Advanced Manufacturing Operational System, or AMOS, is a compact, ruggedised polymer printer designed by the Naval Information Warfare Center (NIWC) Pacific to fill a longstanding operational gap: reliable, field-deployable additive manufacturing for autonomous systems.
Spencer Koroly, a technical project manager at NIWC Pacific, led the effort to build AMOS after a request from a Marine in 2019. “He asked me, ‘What can I take with me to the field tonight to build and repair drones?’” said Koroly. “Back then, there wasn’t a machine that could deliver the speed, material quality, and reliability needed in the field. That was the starting point.”
AMOS was conceived as a dual-use system: suitable for both Department of Defense (DoD) and non-military applications. The core challenge was reducing build time for functional parts. A drone that previously required 150 hours of print time using legacy systems was produced in just nine hours using AMOS. The system was optimised for ABS and ASA rather than lower-grade materials like PLA, ensuring thermal stability and robustness in harsh environments.
“We wanted to take that 150-hour drone print and compress it under a day,” Koroly explained. “It had to be something you could use immediately and trust structurally. Otherwise, you’re just shipping parts again.”
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Extreme testing for AMOS infight and onboard
Koroly’s background in mechanical engineering and robotics helped shape a machine designed both for portability and extreme operational resilience. The 3D printer has been tested inside a V-22 Osprey while in flight, on a Navy Landing Craft Utility (LCU), and during off-road tests in a Joint Light Tactical Vehicle (JLTV), the modern Humvee equivalent. “The printer held up. We got good parts off it even when the vehicle was jumping off the ground,” Koroly noted, including a medical cast printed mid-flight. These scenarios validated the machine’s structural resilience under shock and vibration loads. “The medical cast we printed in flight was completely usable. The design emphasises rigidity. It’s one of the most volumetrically efficient extrusion printers out there,” Koroly said, noting that frame compactness, reinforced motion systems, and minimised moving mass reduce print disruption during vehicle movement.
Koroly described NIWC’s project structure as closer to academia than traditional defence contracting. Engineers submit project proposals, akin to research grants, to develop new capabilities. “I selfishly wanted a printer I could use every day,” he said. “So I proposed building one that could also meet a real operational need.”
Now in its fourth generation, AMOS has already been used in demanding environments. During RIMPAC 2024, five AMOS units were deployed at a Marine Corps base and two aboard the USS Somerset. The project team collaborated with the Naval Postgraduate School and other defense labs to validate how polymer additive manufacturing could complement metal AM in emergency repair workflows. When a reverse osmosis pump on the Somerset failed, AMOS was used to produce a geometry validation part in just eight hours. This polymer test part confirmed dimensional accuracy before a hybrid wire-arc metal AM process was used to produce the final part. “The crew couldn’t produce enough drinking water. That part helped us validate the geometry before committing to a multi-day metal repair. It was a real-world example of additive de-risking the repair process,” Koroly said.
The AMOS program also addresses a larger issue: the Navy’s desire for mobile, localised manufacturing to support distributed operations. Koroly envisions ships and forward bases as “mobile digital warehouses,” enabled by additive technologies. “If the printer is aboard, and the design file exists, you can make the part in hours instead of waiting days or weeks for delivery.”
In parallel, Koroly’s team is evaluating new technologies, including hybrid metal AM processes and AI-assisted part generation. While text-to-CAD systems remain immature, he believes they could unlock manufacturing potential for personnel without traditional design skills. “The person on the factory floor or in the field often knows exactly what they need but lacks the CAD fluency. If AI can bridge that, we unlock a huge capability.”
Still, AM faces persistent barriers to adoption. “The military is often slow to adapt. Additive has long been seen as a solution looking for a problem,” Koroly said. “But we’re now at the point where the tools are reliable enough, and the problems well defined enough, that adoption is accelerating.”
The success of AMOS could signal a broader shift toward distributed manufacturing within the US military, with additive manufacturing forming the backbone of a resilient, on-demand supply chain.
Secure 3D printing systems designed for sensitive applications
Security remains a central concern. Additive manufacturing systems operating in military contexts must meet stringent cybersecurity protocols, particularly for deployment aboard ships. AMOS is undergoing the Authority to Operate (ATO) process, with NIWC’s cybersecurity teams co-developing hardening methods and safeguards for digital design files and machine controls. “We minimise tampering risks using secure file repositories and design verification techniques,” Koroly explained. “AMOS itself must meet cybersecurity requirements before it can be loaded aboard a deployed vessel.”
To ensure compatibility with military systems, the printer has configurable modules to meet cybersecurity and procurement standards. “You can remove or replace components like cameras depending on the deployment environment,” Koroly added. This modularity is key as the project enters its dual-use phase.
The security challenge is not theoretical. During our conversation, we discussed prior public demonstrations where digital files for 3D printed drones were manipulated to fail mid-flight. “There are well-known examples of sabotage via file modification,” said Koroly. “That’s why we rely on secure, government-managed repositories, not open sites, and add scanning and design verification layers before parts are approved for printing.”
NIWC is also addressing the human factors that can determine technology adoption in the real world. “We had Marines build their own AMOS units before deployment,” Koroly said. “It meant they understood the system. When a filament jam occurred, I received a message at 10 pm from a Marine who fixed it in minutes. That ownership matters.” The emphasis is clear: “Imagine you’re sleep-deprived, cold, hungry, and under stress. Now, try to operate unfamiliar equipment. Technology needs to work in that condition.”
The DoD’s first commercial licensee for AMOS is the Chicago Additive project. The group will focus on bringing AMOS to market for industrial users while maintaining the ruggedness, part reliability, and configuration controls that define the original unit.
NIWC is already working toward fleet-wide standardisation. “A university could design a mission-critical part, and as long as the material and geometry standards are met, that file could be manufactured anywhere across a globally distributed military network,” Koroly said.
Additive manufacturing is also gaining operational legitimacy within Navy logistics. Koroly cited the emergence of ships as “mobile digital warehouses,” where polymer printers can produce mission-critical parts in a matter of hours. “We’re seeing the shift now. Back in 2012, we heard about a printer in every home. Today, many parts are becoming digital products. Print-on-demand is real.”
When asked what he would prioritise with unlimited budget and zero red tape, rather than cite a specific technology, Koroly had a different wish. “I’d get the DoD standard locked in,” he said. “A clear standard for polymer additive manufacturing would open up iteration, accelerate collaboration, and transform how supply chains work across defense and industry.”
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Featured image shows AMOS 3D printers deployed during a US Navy exercise. Photo via NIWC Pacific.
