ROCK ISLAND ARSENAL, Ill. -- A contingent of 20 Soldiers, engineers and senior Army leaders convened at the Combat Capabilities Development Command Armaments Center facility here on Jan. 29 to discuss future concepts for a system that uses 3-D printers to help troops keep up with the demand for parts on the battlefield.Soldiers sometimes need parts for vehicles or equipment in hours, not days, weeks, or months, to keep vehicles and Soldiers operating in the field. That's where the 3-D printers in a system -- called the Rapid Fabrication via Additive Manufacturing on the Battlefield -- were designed to help.Known also as R-FAB, the system is a Soldier-operated technology demonstration platform that -- in its current configuration -- opens up into a 24x20-foot workspace and contains five 3-D printers. "There's also computer aided design software, or CAD, so users can design parts in the field," said Thomas Vretis, a general engineer for the R-FAB system who works for the Armaments Center.The printers and associated software facilitate the creation of parts in the field. "Rapid prototyping, as we used to call it -- it's fast," Vretis said.Because 3-D printers use additive manufacturing technology to create accurate parts by building layer upon layer of polymers, Vretis said there's a saying among the system's developers and users: "R-FAB -- Increasing readiness, one layer at a time.""Our challenge was to ensure this future system is smartly designed and doesn't add to a Soldier's overall burden but gives them a new capability to quickly make 3-D printed spare parts in a forward battlefield location, to keep Army systems up and running and ready when needed," said Bob Rossi, who leads the Armaments Center in the development of logistics technology.Vretis said obtaining comments from actual users is important for future system development. "Unfortunately, there is often a disconnection between the R&D engineers and the Soldiers who use their designs," he said. "This meeting gave us the opportunity to get feedback from tactical users with real-world experience. This feedback is invaluable to our design process."The Soldiers were able to enter 3-D "virtual" models of the future design concepts in the Armaments Center's Immersive Engineering Lab here at Rock Island. The lab is a virtual reality "cave" environment that allows at-scale evaluation of large CAD (computer aided design) models.After the lab experience, attendees participated in a type of brainstorming session called an affinity exercise. Ideas were proposed, discussed, and recorded to further influence future design efforts. The user's feedback will be collected and considered when finalizing the design of R-FAB's next generation.Vretis said the Soldiers came prepared, having already considered what types of shelters, trailers and truck combinations would be effective in forward battlefield areas. Among their ideas, Soldiers also requested that power and environmental controls be integrated into the system, an upgrade that the R-FAB team had been considering."It was a great session to get the tactical and engineering communities together. We discussed how to best provide Soldiers with additive manufacturing capabilities in the future," said Chief Warrant Officer 3 Bill Wencil, Ordnance Leader Development Branch, Combined Arms Support Command.Comments with an-in-the-field-oriented view came from Chief Warrant Officer 3 Jeremy Vann, of 1st Special Forces Group, Joint Base Lewis-McCord."I provided a view from both a conventional and special operations perspective, looking beyond the utilization of the technology for battle damage assessment and repair, but also for supporting the Army's Innovation Strategy," Vann said. "Specifically, where additive manufacturing, as an augmentation to existing machining/welding capability, can enhance rapid battlefield repair and enable fabrication of material solutions based on innovative ideas directly from the warfighter."Rossi said the Soldiers provided invaluable feedback based on their recent field experience. "They told us what an optimized tactical Integrated Expeditionary AM Shelter configuration should look like -- and what it shouldn't look like."The gathering of Soldiers and engineers here came soon after a 12-month operational assessment at Camp Humphreys in South Korea, where over 100 unique parts and a total of over 600 parts were created.In operational terms, if a vehicle can't be used because of a missing part, then it's non-mission capable. "We were able to avoid 1,800 non-mission capable days," Vretis said. "You can't put a price on that."Army organizations attending the event to shape R-FAB development or to gain insight into this new additive manufacturing technology area included 1st Special Forces Group, CCDC Armaments Center, CCDC Chemical Biological Center, AFC Sustainment Capabilities Development Integration Directorate, Combined Arms Support Command, Army Logistics University and the Army Advanced Manufacturing Center of Excellence.