COMPLEX GEOMETRY
but there are really interesting things that come as a function of that.”
Voxel combines the words volume and pixel to describe the smallest unit of a 3D digital object.
THE ADDITIVE EQUATION Tere are also significant questions to be answered about the economics of additive. A smart article in Defense AT&L maga- zine in December 2016, “Getting AM Up to Speed,” lays out issues of speed versus cost in additive. Te author, Stacey L. Clarke, then-deputy director of systems engineering for RDECOM at Aberdeen Proving Ground, Maryland, shows the tension between speed and cost.
When time is the driver, cost is less of a factor. When cost and manufacturing reproducibility—both major concerns in Army acquisition—are primary driv- ers, things slow down. When is it worth spending $5,000 on a product to get it now rather than waiting six months for a product that costs only $500? “Tat’s a question that probably needs to have an equation,” Clarke said in an interview with Army AL&T. Tere are other vari- ables to add to that equation, such as how critical the need is or what else might be dependent on the product.
Tat equation might also need to take into account such variables as the speed with which developments are being made in the
discipline. Another significant variable is where the Army puts its money. For the most part, the Army is focusing its efforts on its modernization priorities, and it will be up to industry and academia to develop the breakthrough technologies.
Te Army’s focus is what additive can do today. “We as scientists and engineers can talk about material properties and print bed temperatures and print heads and all this kind of stuff, but the senior leader- ship is looking at, ‘So what? How does this technology improve readiness? How can I keep systems and Soldiers ready to go?’ And that’s what we’re learning,” said Tim Phillis, expeditionary additive manu- facturing project officer for RDECOM’s Armament Research, Development Engi- neering Center’s Rapid Fabrication via Additive Manufacturing on the Battlefield (R-FAB). R-FAB is essentially an additive manufacturing facility in a 20-foot ship- ping container.
“Tere are lots of areas that the Army is looking into, and DOD and other organi- zations are looking into, for 3D printing,” said Dr. Aura Gimm. At the time Army AL&T interviewed her, she managed the Army’s university-affiliated research center program at the Institute for Soldier Nano- technologies at the Massachusetts Institute of Technology, which recently produced 4D (the extra dimension is motion) flex- ible robots via additive. “It’s one thing to create decorative parts, but it’s something
There is much the Army needs: materials developed for additive, and the design tools necessary to both limit the inherent possibilities and exploit them.
80 Army AL&T Magazine January-March 2019
else if you’re trying to create a load- bearing or actuating parts that could fail,” Gimm said.
Te vast majority of the objects created with additive, Gimm said, are essentially decorative. A plastic-polymer mockup of a gear-shifting mechanism for a car design or a reproduction of a missing drawer pull may be nice to have, but the Army requires much more out of the military- specification articles it procures.
Some, though, like Humvee gas caps and the junctional tourniquet created by the Army Rapid Equipping Force’s (REF) Expeditionary Lab (Ex Lab), are not a great deal more substantial in terms of their physical structure, but are consider- ably more useful than decorations.
However, the point that Gimm made is something that Army scientists and engi- neers have to keep in mind: Items made for the operational Army have to withstand considerable stresses. “Te standardization and making sure that we have metrology or the metrics to test and evaluate these parts,” Gimm continued, “is going to be quite critical, for [items made with addi- tive] to be actually deployable in the field. Because one thing that we don’t want is to have these parts … not work as expected.”
Tat’s something that Perconti empha- sized in his remarks at the opening of the AMMP Center. “Ultimately, the goal for us is to enable qualified components that are indistinguishable from those they replace. Remember, when you take a part out of a weapon system and replace it with an additive manufactured part, you’re putting lives on the line if that part is not fully capable. So we have to be very sure that whatever we do, we understand the science, we understand the manufacturing, and we understand that we are delivering qualified parts for our warfighters.”
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