Additive Manufacturing Provides Agility for Defense Contractors

Despite relatively low demand for spares or few platform orders, the industrial base must be responsive over long periods. For metal cast parts, the cost and long lead time of tooling fabrication presents a challenge. Additional problems come from storing tooling during the decades of a weapon system’s operational life.

The America Makes project, managed by the Air Force Research Laboratory, is applying additive manufacturing, or 3D printing, to this problem. The emerging results of this public-private project demonstrate that leveraging this technology, specifically for tooling applications, empowers original equipment manufacturers and their supply chains to increase industrial base agility, improve manufacturing efficiencies and boost the number of companies who may participate in lifecycle support. 

Sand casting, where the material is used to make a mold, is the traditional way to cast metal. The tooling to create a sand mold traditionally involves making a pattern in the same shape as the end product and boxes to create sand cores to prevent molten metal from filling cavities during the final casting. For example, when casting an engine block, its shape would be based on the mold while cores would keep open interior passages for fuel, oil and air. Fabrication of the patterns and core boxes result in significant time and costs in the manufacturing process.

In 2014, America Makes — a public-private partnership seeking to increase U.S. competitiveness in the areas of additive manufacturing and 3D printing — funded a technology transfer program to accelerate the technology integration of binder jet sand printing for mold and core tooling production, which is part of the metal casting industrial base. 

America Makes leans on the applied research capabilities of its universities, the business expertise of its industry members and the educational and technical capabilities of the American Foundry Society to accelerate technology adoption. This public-private approach has resulted in increased agility in the U.S. metal casting base.

Rob Gorham, director of operations at America Makes, said: “We knew this project would clearly demonstrate 3D printing for tooling is a near-term opportunity.” Engines, transmission housings, hydraulic assemblies and landing gear are a few examples of metal cast components on Defense Department platforms that benefit from the process.  

The effort had a much broader appeal than just defense related manufacturing. Caterpillar Inc. was the first manufacturer to join the project. Rick Huff, technical team leader for manufacturing technology at the company, said Caterpillar wanted to integrate a range of additive manufacturing technologies into its tooling production.

“We clearly see the value of being able to print core packages where tooling no longer exists in the supply chain or where it needs to be modified quickly to meet emerging customer requirements,” he said. The company is integrating additive manufacturing technologies in its enterprise at an accelerated pace, he added.

Rick Lucas, chief technology officer for ExOne Co., a 3D printer manufacturer, said the metal casting industry is an appropriate early adaptor of the technology. “Leveraging of a very mature technology like binder jet sand printing is an immediate opportunity by which small, medium and large companies distinguish themselves in posturing for high value business opportunities. As an equipment and service provider ExOne continues to see significant growth in the metal casting sector worldwide.” 

Jerry Thiel, director of the University of Northern Iowa’s metal casting center, envisioned a much more agile U.S. supply chain as a direct result of the ability to print complex core assemblies. “Since the inception of this America Makes project our university has been overwhelmed with informational visits requested by OEMs, foundries and technology companies, all of whom come to us for an objective perspective on how this technology may help them speed product development, increase supply chain efficiencies and posture them for higher revenue markets.” 

Three-D printing for tooling production also enables improved manufacturing efficiencies in the supply chain.

Tom Prucha, vice president for technical services at the American Foundry Society, said the U.S. metal casting base will embrace a hybrid manufacturing approach that results in greater efficiency. Additive manufacturing “technologies are well suited for a hybrid approach in which pattern shops and foundries use traditional tooling to fabricate sand molds and use 3D sand printers to make complex core assemblies as one component versus multiple core packages required in traditional tooling approaches. Reduced foundry labor input is an additional benefit,” he said.  

Jiten Shah, president of Product Development & Analysis LLC of Naperville, Illinois, emphasized the tremendous schedule advantages regarding tooling elimination for castings. “Leveraging of 3D-printed cores and molds provides OEMs significant agility. The process offers design engineers tremendous design flexibility regarding casting design. The utilization of modeling and simulations tools to support these design enhancements ensures our metal casters achieve success on the first pour. Thus, material, labor and schedule issues for urgent part orders are addressed.”

The U.S. metal casting sector is benefitting from this technology adoption via multiple American Foundry Society workforce development efforts. It facilitated an additive manufacturing workshop at the 2015 National Casting Conference held in Columbus, Ohio, to a standing-room-only crowd of approximately 200. During the Q&A session, small and medium companies interacted with original equipment manufacturers on case studies and impacts. 

John Danko, president of Danko Arlington Foundry in Baltimore, Maryland, said his company is an example of how the integration of additive manufacturing technologies for tooling increases efficiency.

In the past, the foundry’s craftsmen created patterns for sand molds in its 10,000-square-foot wood shop to make parts for Defense Department clients. “Now we leverage 3D printers and CAD technicians to convert a two dimensional drawing to create a 3D model and produce tooling to cast the part. It is a very efficient process. Our defense business continues to increase exponentially based on our work quality and responsiveness. We are producing hundreds of critical parts for defense applications leveraging additive manufacturing,” Danko said. 

Tooling investments are no longer an entry barrier for innovative small companies that have the expertise to use additive manufacturing. For example, the America Makes Foundry Consortium utilizes three industry leading pattern shops from the Midwest to inform and provide original equipment manufacturers with real-time cast metal part production capabilities.

“This technology enables us to service commercial and defense OEMs and their affiliated foundries even if they don’t have a pattern on hand,” said Keith Gerber, president of Hoosier Patterns, the first U.S. pattern shop to buy an ExOne S-Max binder jet sand printer.

“Past tooling investments are no longer a constraint for us to produce a part in a cost-effective manner,” he said. Thus, the number of small businesses that can respond to a Defense Logistics Agency call for spares increases significantly, he added.

Two Ohio pattern shops are additional examples of small businesses that, like Hoosier, embrace the additive manufacturing technology application when it is appropriate. XL Pattern Shop of Orville, Ohio, and Humtown Products of Columbiana, Ohio, also employ sand printing services. They have used the technology for several years in support of parts for the aerospace sector and has grown their staff of CAD technicians.

Brandon Lamoncha from Humtown Products assists his customers in deciding how they can use this printed tooling approach. “The part geometry, volumes and turn-around time are all factors we discuss regarding whether a printed core package makes sense. However, the driving factor for this technology application may be our ability to print one very accurate core assembly versus multiple core assemblies. The client’s design requirements can now be optimized.”

While some in the defense sector might see these as new trends, others in the commercial sector have employed these processes for years.

Harold Sears, a technical specialist on additive manufacturing at Ford Motor Co. said, “We have significantly reduced product time to market as well as total sunk tooling costs via the application of additive manufacturing technology for production tooling at Ford. We have been doing this for over 25 years. It saves time and money and helps us maintain our position as a globally competitive company.”    

The emerging results of this America Makes effort demonstrate that additive manufacturing leveraged for tooling applications empowers manufacturers and their supply chains to increase overall industrial base agility, improve manufacturing efficiencies in the supply chain and potentially boost the number of companies who may participate in lifecycle support. Collectively, these aspects should result in increased platform availability and reduced sustainment costs.

Rich Lonardo, a consultant in support of advanced manufacturing programs at the Youngstown Business Incubator and America Makes, is a former Army acquisition officer and science advisor to combatant commands. Brett Conner is an associate professor of mechanical and industrial engineering at Youngstown State University, where he serves as the director for advanced manufacturing workforce initiatives.

Topics: Business Trends, Doing Business with the Government, Defense Contracting, Manufacturing