Big Metal Additive founder Slade Gardner says his company has the largest, most sophisticated metal hybrid additive manufacturing capability
Not far from Colorado’s Rocky Mountain Arsenal National Wildlife Refuge sits an unassuming building in an ordinary industrial park. The activities taking place within this building are anything but average, however. Step inside and you might see a torpedo-shaped functional prototype of an unmanned underwater vehicle (UUV) for the Office of Naval Research, or a spindly, topology-optimized airframe component more than five feet across that the Air Force will use in its ORB eVTOL (electric vertical takeoff and landing) project.
These are just a few of the unique, sometimes secret parts produced at Big Metal Additive LLC’s facility on Paris Street. As with those just described, many are for the U.S. military, but you’ll also find everything from a 27” hand wheel used to crank open a hydraulic gate valve to a three-way air manifold for a customer who needed a quick turnaround casting replacement. And as you might have guessed from the company name, some are quite large—the tables on BMA’s custom-built, five-axis hybrid additive machining centers measure six feet across and twice that in length, and are capable of wire-arc deposition and machining of fully dense, very complex metal parts that would otherwise be impossible to produce.
The person behind all this additive magic? Dr. Slade Gardner, recent recipient of the Society of Manufacturing Engineers (SME) AM Industry Achievement Award, who founded Big Metal Additive (BMA) in 2016. Ironically, he began his career with plastics.
“My undergraduate was in chemical engineering at Pennsylvania’s Lafayette College,” Gardner said. “I went directly to Virginia Tech after that, which I consider the top-rated school in the discipline of advanced manufacturing. The National Science Foundation had sponsored a Science and Technology Center for high-performance polymeric adhesives and composites there, and at that time, it was exactly what I wanted to do: take polymer composites to the next level for use in high-performance applications.”
In 1997, Gardner graduated from Virginia Tech with a doctoral degree in polymer science and engineering. He spent the next two years with BP Amoco’s carbon fiber research and development group before moving on to Lockheed Martin, where he would work for the better part of two decades.
During much of his early tenure there, he focused on polymers and nanocomposites. At one point, Gardner developed a multi-axis robot cluster attached to a central turntable—while one robot was depositing plastic, the other machined the burgeoning workpiece. Yet he soon heard the call of large-format metal additive; he took what he’d learned from his polymer experiences and used it to build titanium propellant tanks—first in the laboratory, then on the factory floor, and finally seeing them qualified for commercial space use.
That was a big achievement, he noted, and it was a good learning experience. It helped Gardner identify and understand the problems encountered when building large metal parts. Knowing that he would be unable to fix those problems while working for another company, he decided to strike out on his own. “That’s when I resigned from Lockheed Martin,” he said. “It was probably the greatest training grounds imaginable for developing the technical skills needed for what I wanted to do next. I’m very grateful for what I learned there.”
He’s also grateful for his induction as a Fellow at Lockheed Martin, a position he held for three terms, a total of nine years. Two of those terms were at the Space division, what was then called the Advanced Technology Center. Not yet 40 years old, Gardner was the youngest Fellow in the company. “Most of my contemporaries were toward the end of their careers, so it was an honor to be inducted at such an early age.”
Now self-employed, Gardner embarked on a two-year deep dive of technology definition and development. He went through several iterations of machine design before building his first hybrid additive CNC, which began making customer parts in 2018. He gathered a team of sixteen engineers, business managers, operations specialists, summer interns, and “occasional comedians” and set about capturing the manufacturing contracts needed to keep his small company afloat. As with most of Gardner’s previous endeavors, he was successful.
“Today, we perform large-scale hybrid additive manufacturing on two machines, with three more on the way,” he said. “We’ve found that having multi-axis metal deposition and multi-axis CNC machining capabilities in the same equipment opens up all kinds of possibilities for product design and optimization.”
They’ve also solved many of the metal additive problems that he identified years earlier while at Lockheed Martin, chief among them the ability to scale for large parts, deliver high-quality surface finishes, and meet tight dimensional tolerances. With all this came an unexpected but happy discovery—the parts produced with BMA’s unique five-axis deposition process provided superior isotropic mechanical performance, what Gardner described as “a very significant benefit.”
Despite BMA’s progress in this area, much work remains. Gardner suggested that additive manufacturing—large scale or otherwise—has yet to become industrialized and “lacks a factory focus.” He said it doesn’t matter how many 3D printers a company owns or even how fast those machines can produce parts. What’s important is that the software and hardware platforms the manufacturer uses are industrial in nature—that the CAM systems and machine controllers and automation platforms were designed with the factory in mind, and not based on AM’s “prototype only” legacy.
Embracing this mentality offers numerous advantages over those that still operate with a service bureau mentality. Chief among these is an existing talent pool containing hundreds of thousands of trained machinists and programmers who already know how to use industrial CNC equipment, and are comfortable working in these environments.
“When starting a manufacturing company, why not utilize the tools that already exist, and that includes the people,” Gardner said. “Doing so means you don’t have to create training programs that introduce your workforce to new controller types or software platforms. You can also function in the model-based engineering world that design engineers and procurement people are accustomed to, and are not limited to meshes and STL files like many additive shops. Simply put, we speak the same language and operate on the same terms as traditional manufacturers, except we use non-traditional technology. Because of that, we’re very agile.”
Here again, however, much work remains. Model-based engineering (MBE) has yet to exploit the immense design opportunities that additive presents, Gardner pointed out, let alone leverage what’s possible when the 3D printer has five-axis deposition capabilities and is equipped with a five-axis milling head—in this situation, traditional AM concerns over accuracy and surface finish fall to the wayside, while those who design and develop manufactured products gain an additional level of design freedom.
He explained that model-based engineering is meant to streamline the engineering, manufacturing, quality assurance, and customer support processes. Everyone is working with the same model, they’re all on the same page, and there’s no need to interpret drawings or specifications. When applied in an industrial setting, AM can interface directly with that model-based enterprise. “There’s still plenty of work to do, but I think additive has the clearest glide path to success in this area.”
Gardner is also a big fan of virtual and digital twins. “Personally, I believe this technology is a key ingredient to the future of manufacturing and will differentiate high quality, sophisticated products from low-cost, run-of-the-mill commodity parts,” he said. “More importantly, I feel that the virtual twin and its gradual evolution to a digital twin, a serialized 3D solid model that not only contains the design intent but all of the part’s manufacturing history—that’s going to bring United States manufacturing back into a position of dominance.”
Until that time, he and his team will continue to build on BMA’s already extensive capabilities. He said they’ve become adept at making large pressure vessels and hemispherical tanks, and can accomplish this without the support structures common to metal AM. On these and other projects, they make extensive use of topology optimization, despite Gardner’s comment that this is yet another example of not-quite-ready-for-large-scale prime time technology.
“That’s true as well for CAM software, which is why we’re part of the Siemens software partnership program,” said Gardner. “They’ve provided incredible support to us in developing toolpaths and additive workflow strategies, and together we’re evolving our topology optimization tools to complement our large-scale additive manufacturing capabilities.”
Gardner closed by making an uncomfortable statement: our country is falling behind. “I think we’ve made some mistakes,” he said. “Additive manufacturing has captured the imagination of many people. They’re enamored with the technology, and while I totally understand and agree with that, most of the development efforts have focused on elevating AM’s technology readiness level, not its manufacturing readiness level.”
Stated another way, most of the investments made so far have focused on putting 3D printers in laboratory environments for the sake of proving their capabilities. “This is all fine and good when technologies are first developing, but it’s well past time to be done with that. We need to put additive manufacturing into factories and we need to do it now. Until we can commercialize the technology for use in industrial applications and develop all of the infrastructure required to support that, we will never achieve the manufacturing readiness level necessary for our nation’s security. That’s how important this is.”