Researchers at the U.S. Army Armament Research, Development and Engineering Center (ARDEC) successfully fired the first grenade created with a 3-D printer from a grenade launcher that was produced the same way. is a tangible testament to the utility and maturation of additive manufacturing. It epitomizes a new era of rapidly developed, testable prototypes that will accelerate the rate at which researchers’ advancements are incorporated into fieldable weapons that further enable our warfighters.
RAMBO and the test rounds were fired for the first time last October at a facility in New Jersey. According to the researchers, 15 test shots were fired, with muzzle velocities matching conventional grenade launchers to within five per cent. Furthermore, the weapon showed no signs of degradation after firing.
RAMBO is based on the 40mm M203A1 grenade launcher, which contains 50 components. All of these, with the exception of springs and fasteners, were produced using various additive manufacturing techniques. The barrel and receiver were fabricated from powdered aluminium using direct metal laser sintering (DMLS) in a process that took about 70 hours. Other components, including the trigger and firing pin, were printed using 4340 alloy steel, which is the same material used to make the weapon by traditional methods.
“Designs and parts previously unachievable can now be realised. Complex designs that lighten, simplify and optimise armaments are now feasible and manufacturable,” they said.
3D printing is revolutionizing defence by printing small components to full drones on naval vessels, replacement parts for fighter aircrafts to printing ammunition. Substantial improvements have been made in 3D printing with the fabrication of 3D objects from metals, ceramics, plastics, and even multi-material capabilities.
John Burrow, deputy assistant secretary of the Navy for Research, Development, Test and Evaluation said, “Additive Manufacturing will fundamentally change how we think, how we do business, the cost variable, and how we make decisions,” said Dr. John Burrow. “I think you are about to see its operational and technical potential literally explode off the map.” Burrow and Navy officials envision a future with 3-D printers forward deployed with Marines and installed aboard warships as well as shore-based commands.
Marine Lt. Col. Howard Marotto noted that additive manufacturing is at the core of the Pentagon’s Third Offset Strategy. “I will tell you, frankly…AM is the foundation for the Third Offset,” Marotto said. “Levering the technology as agnostic as it is…is really the key if you’re going to operate as a Marine Corps in a distributed ops environment. Everything from being able to print your own parts in stream…to printing your own UAVs for ISR, for weaponization, on site, custom made, with sensors to do that exact mission that you need at that exact moment.”
3D printing or additive manufacturing is ongoing revolution in manufacturing with its potential to fabricate any complex object and is being utilized from aerospace components to human organs, textiles, metals, buildings and even food. Additive manufacturing, is defined by ASTM International as the process of joining materials together, layer by layer, based on three-dimensional model data. It increases design possibilities, enhances the speed of innovation, and offers an alternative for creating shapes closer to what an engineer might need, with fewer constraints.
NASA and the US military used 3D printed components to successfully test advanced prototype airplanes, spacecraft and even ground vehicles. In March 2016, the Navy successfully test launched three Trident II D5 Fleet Ballistic Missiles made by Bethesda, Maryland-based Lockheed Martin. The one-inch wide aluminum alloy connector backshell component protects vital cable connectors in the missile. The backshell component was designed and fabricated entirely using 3D design and 3D printing, a process that allowed Lockheed Martin engineers to produce the part in half the time it would take traditional methods.
Sailors and Marines are already developing new products and complex systems like drones and even munitions, expanding the realm of possibilities made real by 3-D printing while saving time, resources, and money.
3D printed munitions
Marine Corps’ Next-Generation Logistics recently printed, and then detonated, an indirect fire munition at Naval Surface Warfare Center Indian Head, Maryland. The munition, proved more lethal than traditionally manufactured munitions. And testing showed it could be developed to further improve lethality or otherwise tailor the system to the mission.
“One of the benefits of being able to precisely control the way that a munition or warhead is ‘grown’ through [additive manufacturing] is that we think we’ll be able to tailor the blast and associated fragmentation to achieve specific effects for particular targets, heights, collateral damage, or even environmental considerations,”Capt. Chris Wood, the co-lead for 3-D printing said. “Some of this can be done currently with very expensive, hand-made munitions, but [additive manufacturing] allows us to do it better, faster and likely cheaper.”
For the Marine Corps, which has more than one aging vehicle model reaching the limits of its service life, 3-D printing can be a cost-effective way to manufacture parts no longer in production
In 2015, U.S. Navy sailors trialed the use of additive manufacturing (3D printing) technology to build a miniature quadcopter aboard USS Essex (LHD-2) and fly it around the hanger deck. British Royal Navy ship HMS Mersey has launched an inexpensive 3D-printed drone from its gun deck. The 1.5m wingspan, propeller-driven drone, known as “Sulsa,” was 3D-printed on shore and later assembled on the ship.
The test demonstrated how more-or-less disposable drones that could be 3D printed on board would cut costs and let a crew adapt quickly to a new mission such as after a natural disaster. The Institution of Mechanical Engineers explained that, “Within five years, ships could be equipped with multi-material 3D printers able to produce entire unmanned aerial vehicles, tailored to specific missions.”
“3D printing is ideal for limited production runs, for instance if you want five [unmanned underwater vehicles] for a particular mission. It could take just two days to manufacture a plastic hull and insert the electronics”, said Jones, a production engineer.
For deployed naval forces, the key benefits of 3D printing are a shorter supply chain with reduced spares inventories (releasing space onboard ships for more valuable stores or equipment) and improved availability, according to Paul Jones, director of U.K.-based consulting firm Arke Ltd.
US Navy to develop 3D printed components for missile propulsion system
Recently contract has been awarded to Oregon-based Metal Technology (MTI) to develop and demonstrate 3D printing techniques for missile propulsion components. Specifically, they will be developing and demonstrating viable 3D printing aerospace techniques for the low-cost production of refractory metal components, which will be used on the Navy’s propulsion system for the Trident D5 missile system. This is a submarine-launched ballistic missile system (SLBM) that is a key part of the US strategic nuclear triad
Through this contract (a Small Business Innovation Research or SBIR contract), MTI will now be working to reduce the costs and complexity of that method. 3D printing, they believe, is a key tool in significantly reducing that complexity and lead-time, as well as the costs involved.
Jason Stitzel, the Director of Engineering for MTI, further revealed that the propulsion systems came with very complex requirements for the 3D printed parts. “Key performance requirements for the additively manufactured refractory articles include surviving exposure to greater than 3,200 degree Fahrenheit gaseous environment for 10 minutes at 550 psi, and achieving mechanical properties that meet or exceed the properties derived from traditional processing methods,” he said.
US Navy’s “Print-the-Fleet” initiative
Via their ‘Print-the-Fleet’ project, the Navy is trying to educate sailors about 3D printing and further integrate its use into everyday operations. The experiment has produced several applications for tooling, molding, repairs, prosthesis, cranial implants, and custom parts both on land and at sea.
The US Navy’s Vice Admiral Philip Cullom, who is charged with the Navy’s “Print the Fleet” additive manufacturing initiative, has stressed that the Navy’s logistical supply chains are vulnerable and costly, and that additive manufacturing can offset some of that cost, particularly in austere times.
Army researchers are exploring many frontiers of this exciting technology, “Imagine the possibilities of three-dimensional printed textiles, metals, integrated electronics, biogenetic materials and even food,” said Dale Ormond, Director of Research and Development.” “The vision is to be able to have additive manufacturing as a tool in the toolbox so that Soldiers can manufacture and produce a product as close to the point of need as possible,” said Andy Davis, program manager for the Army’s Manufacturing Technology program (ManTech).
And then there’s the warheads; “3D printing of warheads will allow us to have better design control and utilise geometries and patterns that previously could not be produced or manufactured,” Zunino said , a materials engineer for the Army.
Food researchers in the US Army are looking into ways to 3D print food for soldiers that could produce meals on demand for soldiers in the battlefield. By combining wearable technology capable of measuring a soldier’s individual physiology with food 3D printers, future Meal Ready-to-Eat (MREs) will be automatically generated meals that have been tailored for the specific nutritional needs of each soldier. Because the Army’s Meal Ready-to-Eat (MRE) standard for food has a shelf life of three years, 3D printing creates new options that could make meals have longer and more stable shelf lives according to Lauren Oleksyk, Natick Soldier Research, Development and Engineering Center (NSRDEC).
Dr Thomas Russel, Director of the Army Research Lab said: “For soldiers, there are some medical benefits. Many of the injuries soldiers receive in the field are not traditional. A lot of the medical community sees this as a new approach to medicine. We can 3D scan injuries.”
RDECOM partners with the Army’s Rapid Equipping Force to manage, staff and support expeditionary labs, or “ex labs,” which can be deployed worldwide. Ex labs are designed to supply innovative equipment to forward-deployed Soldiers as quickly as possible. One lab is currently located at Bagram Airfield in Afghanistan and another at Camp Arifjan, Kuwait.
Each ex lab is built into a 20-foot shipping container and two ISU 90 shipping containers, which hold a 3-D printer as well as supporting equipment and the computer-aided design workstation used to create the virtual working models that are then constructed by the 3-D printer. The labs are also stocked with traditional tools, equipment and software to design and fabricate metal and plastic parts
The on-site ex lab team includes a Rapid Equipping Force noncommissioned officer in charge, a RDECOM lead engineer, a support engineer, and a machinist. Together, they develop solutions using textiles, electronics, subtractive manufacturing and additive manufacturing.
“The labs have an open-door policy so the Soldier can come in and describe his mission capability shortfalls, and the [ex lab] team immediately starts brainstorming ideas and solutions,” said Angel Cruz, RDECOM ex lab project lead.
RDECOM plans to develop additive manufacturing in three phases. Phase one will use additive manufacturing to repair and replace existing parts. Phase two will reduce multipart assemblies from a series of parts to one part.Phase three will use additive manufacturing to create new parts that don’t already exist.
Additive manufacturing technology roadmap
The Army recently completed an additive manufacturing technology roadmap, which was sponsored and managed by ManTech. The project, which began this year, includes RDECOM, program executive offices, the acquisition community and Soldiers, and provides strategic guidance across the Army materiel and life cycle management communities.
The roadmap covers four key areas critical to using additive manufacturing efficiently and effectively:
— Materials: what must be done to develop, mature and capture associated data for materials.
— Design: how to develop and use advancements in the computer-aided design and engineering fields for additive manufacturing products, as well as how to best use the capabilities.
— Process: what additive manufacturing processes can be used to make AM parts, and what process capabilities are needed.
— Value Chain: the most efficient and cost-effective way to use AM and the infrastructure required to support it.
Army’s “On-Demand Small Unmanned Aircraft Systems”
In December 2016, engineers from the Army Research Laboratory flight tested 3-D-printed unmanned aircraft created with a new on-demand system. Army’s “On-Demand Small Unmanned Aircraft Systems” developing new technology that will allow Soldiers to request small unmanned aircraft system on the spot with the use of 3D printing. “We’ve created a process for converting Soldier mission needs into a 3-D printed on-demand small unmanned aircraft system, or ODSUAS, as we’ve been calling it,” explained Eric Spero, team leader and project manager. Based on the feedback engineers received from Army leaders, Eric Spero said, his team plans to work on improving noise reduction, standoff distance, and agility, as well as increasing the 3-D-printed drone’s payload capacity.
“A reconnaissance patrol requires UAV support and sends mission requirements to the fabrication lab. ARL software configures a UAV based on the Soldiers request and designs the vehicle with off-the-shelf and 3D printed parts. The pieces are then assembled and the UAV is sent to out into the field within 24 hours of the initial request.”
“The technology provides an unmanned teammate in support of manned/unmanned teaming,” Eric Spero, an acting team lead in the ARL Vehicle Technology Directorate wrote. “Small UASs equipped with sensors, for example, day or night, still or video, can provide preemptive threat detection and identification.” If small UASs are built on-demand, they can be customized to autonomously deliver specific supply classes via air.
“Small UASs can also be used to investigate weapons of mass destruction at a safe stand-off distance, looking beyond gaps, collecting forensic data, and breaching complex obstacles such as those that require hover-flight capability,” Spero wrote.
“The solution is envisioned to be available at the battalion level and below, supporting the company, platoon, squad and individual Soldier,” Spero said.
“We saw the trajectories of two beneficial technologies converging, 3D printing and small unmanned air vehicles, to support small unit decentralized decision making in complex environments,” said Eric Spero, an acting team lead in ARL Vehicle technology directorate.
3D Systems has announced its partnership with U.S Army Research Laboratory (ARL), America’s premier research center for land forces. This partnership is to jointly develop 3D printing technology and materials for automotive, medical, wearable, aerospace and other commercial and defense applications at the Army’s Aberdeen Proving Ground at Maryland.
“Additive manufacturing is redefining what is possible. Novel materials research will enable areas like 3D printed electronics and multi-functional structures. The development of hybridized manufacturing technologies will allow in-field manufacturing, efficient depot-level repair and a reduction of the Army’s overall logistics burden,” said Larry (LJ) Holmes, the Army Research Laboratory’s Principal Investigator in this effort. ”
Late last year, British Royal Air Force made history when one of their Tornado fighter jets took off with 3D printed replacement parts. “It’s long term, but it’s certainly our end goal to manufacture an aerial vehicle in its entirety using 3D printing technology,” Matt Stevens, who heads BAE’s 3D printing division, told AFP. In the future, a plane shall be able to print another plane inside itself and then launching it from its undercarriage.
“Additive manufacturing can address a multitude of challenges for us, and there is a big pull to implement these processes from the logistics community,” said Dr. Jonathan Miller, a materials scientist and the additive manufacturing lead for the AFRL directorate. “The fleet is aging, and replacement parts for planes built 30 years ago often no longer exist. Rapid production of a small number of hard-to-find parts is extremely valuable.”
The US Air Force’s (USAF) Oklahoma City Air Logistics Complex (OC-ALC) is set to implement its strategic plan to integrate 3-D printing technology into every aspect of its airpower sustainment mission. The 3-D printing machines will be able produce replacement engine parts directly at repair and overhaul sites from the provided raw materials, including metal pellets, ceramics and gypsum, the USAF stated.
3D Systems have been awarded two different research contracts worth in excess of $1 million by the US Air Force Research Laboratory (AFRL). Per the contracts, 3D Systems would develop advanced aerospace and defense 3D printing manufacturing capabilities at a large scale for possible uses within the US Air Force. “The main advantage of the printer is that you are no longer limited in geometry, for example, when you want to create a space inside a block of aluminum or a ring inside a ring.”
However, the need to develop consistent, quality materials for additive manufacturing still remains a challenge that AFRL researchers are working diligently to address. Engineers need to have full confidence in additive manufactured part alternatives as they implement them as replacements in aging fleets or as system-level enablers in new weapon systems.
Extension to Functional Applications
Dr. Dan Berrigan, the additive lead for functional materials at the directorate, is exploring ways to use additive manufacturing processes to embed functionality into structure, such as by adding electronic circuitry or antennas on non-traditional surfaces. “Additive processes enable us to deposit electronic devices in arbitrary shapes or in flexible, soft form factors,” said Berrigan. “We are looking at different ways to make a circuit that can enable them to bend or adhere to new surfaces or geometries, such as on a dome or patch. Essentially, we are looking at ways to add capabilities to surfaces that already exist.”
For 3-D printed electronics, a conductive material is divided up into millions of small pieces and suspended in a liquid that is then dispensed from a printer, explained Berrigan. After printing, those individual conductive pieces must maintain contact to enable electrons to move through a circuit and create power. “The demand here is for low-cost, flexible electronic devices, and these direct write, additive processes give the community design capabilities that we cannot achieve otherwise,” said Berrigan.
3D printed micro-drones dispensed in swarms from fighter jets
The Pentagon’s Strategic Capabilities Office (SCO) conducted an experiment under which micro-drones, created with 3D printing technology, could be launched from the flare dispensers of various US fighter jets. They are parachuted down in small-sized canisters, where the micro-drone wings then catch the wind with their one-inch propellers. According to SCO director William Roper, the 3D printed micro-drone swarms have been under testing since 2014, and aside from the canister launching, can also be dispersed by ground troops as well.
Each micro-drone weighs just about a pound each. The swarms are able to come together in packs and influence situational awareness from the moment they come out of the canister. They could potentially be used to confuse opposing forces and carry out more cost-effective surveillance missions. 3D printing technology helped to ensure that the micro-drones had the appropriate strength for their miniaturized size.
Challenges for 3D printing
Despite years of development and research into additive manufacturing processes, there are a number of implementation challenges that AFRL researchers need to address in order to enable greater Air Force benefit from the technology, both now and in the future. “Fundamentally, it comes down to a materials processing problem,” said Berrigan.
The lack of standardized production processes, quality assurance methods, significant material variability and reduced material performance are just some of the factors AFRL researchers need to overcome. Depending on the application, material performance can be related to the strength of a part. For example, the electronic properties of an additive manufactured circuit may be worse than those of ones traditionally manufactured.
Another issue centers on basic materials compatibility. “There are a lot of different interfaces in additive manufacturing, and ensuring that materials adhere to one another or that a part can support a certain stress or withstand a certain temperature—these are all challenges we need to address,” said Miller.
The technology also has disadvantages in some cases since some jet engine components must be capable of withstanding extremely high temperatures and physical stresses. OC-ALC top scientist and engineer Dr Kristian Olivero added: “For metals in particular, the additive manufactured properties are typically somewhat lower, so what you gain in speed and flexibility, you lose some mechanical properties.
“Additive manufacturing will not provide the correct surface finish for a Class A screw thread in a crankshaft main bearing,” said Paul Jones, director of U.K.-based consulting firm Arke Ltd.
“While 3D printing gives you net tolerance – the correct dimensions – it won’t necessarily give you the right finish, so you need a CNC [computer numerical control] machine for reductive manufacture on top of the additive manufacture”, Jones explained.
However it may take some time before 3D printing can build a complete functioning weapon like a missile.
“Before a warfighter can print a missile in the field,” Chris McCarroll, Raytheon director for the Raytheon University of Massachusetts Lowell Research Institute, explained, “you need [a] quality, controlled processes to fabricate all the component materials: the metallic strong backs, and the plastic connectors, the semiconductors for processors, and the energetics and propulsion systems. The hard part is then making the connections between these components, as an example, the integrated control circuit that receives the command to light the fuse. At some relatively near-term point you may have to place chips down and interconnect them with printing. Or, in the future, maybe you’ll just print them.”
The long-term goal, according to Berrigan, is for additive manufacturing to become a well-understood tool in an engineer’s toolbox, so that unique components can be design-integrated into a system. It’s difficult to go back in a system already built, he said, but additive manufacturing provides the opportunities to build-in greater potential at the start.
“The long-term vision is to have functional and structural additive manufacturing to work more cohesively from the start. Rethinking systems-level design to incorporate functionality such as electrical wiring, sensors or antennas is a potential that additive can help us address,” he said. “When you build something by layer, why not introduce channels for sensors, cooling or other functions?”
There are also safety concerns relating to hazardous materials. One 3D process requires the presence of argon gas, which is heavier than air so in the event of a leak may collect in the bowels of a ship with potentially suffocating results.
The metal powders which are used to construct finished items, layer by layer, are explosive and will also require very careful storage and handling.
“Aluminium powder is massively dangerous”, said Jones, “so you wouldn’t want to keep it near where fire is possible, or where you could have an intrusion. Keep it in the weapons magazine”.
“Understanding the safety, reliability and durability of a part is critical for an aircraft. We know this for parts made through other processes, but we don’t know this yet for additive,” said Berrigan.
3D printing could be exploited by Hackers
A report was developed by the National Institute of Standards and Technology – NIST, which is part of the Department of Commerce – to warn contractors of the various vulnerable and exploitable points in the way 3D printing is used by various companies, and is not something that has come out of nowhere.
The two primary threat vectors are via network connectivity and nonvolatile storage media. When devices are not protected by applicable security controls, network connectivity and information stored within nonvolatile storage media may be used to compromise organizational information or disrupt the device.
According to the report, hackers can exploit unprotected 3D printers in a variety of ways. Some of the dangers listed are:
- Denial of service (DoS): to make printing services unavailable.
- Spams may waste materials while also result in denial of service for legitimate users.
- Exploiting default administration/configuration passwords to control the device locally or remotely via a web interface.
- Intercepting / Alteration / Corruption of unencrypted data and information.
- Vulnerabilities of commercial embedded operating system.
Hackers can exploit 3D printing technology by stealing or altering information designs, rendering your printers unusable, or corrupting your settings to make devices overheat or even explode. And of course, there is the theoretical possibility that 3D printing designs are altered with malicious intent as a method to sabotage constructions, weapons or defense systems.
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