Expeditionary Fabrication in the Marine Corps

Additive manufacturing (AM) has evolved from an emerging technology to a primary influence in the design and fabrication industries. AM, also known as 3D printing, is the process of additively layering a construction material—anything from powdered metals, to concrete, to living cells—to build an object based on a digital model, generally a 3D computer-aided design (CAD) file. AM differs from traditional subtractive manufacturing, in which an object is created by removing material through machining, milling, carving, etc.

From creating functional human body parts (such as replacement joints) to printing diesel engines to building complete weapon systems or replacement parts, AM applications are limited mainly by imagination. For the U.S. military in particular, the capability to print replacement parts on demand for damaged systems and obsolete equipment—and at the point of need—has begun to permeate and challenge traditional acquisition and maintenance processes.

The Marine Corps has introduced “expeditionary fabrication” (XFab) to make AM deployable, so units in remote locations can operate with shorter supply chains and take advantage of innovative maintenance solutions.

Countless extraordinary examples of recent military AM applications exist, including:

• A Mk 8 Mod 1 SEAL Delivery Vehicle hull printed at Oak Ridge National Laboratory at a fraction of the cost of a conventionally built system—and in less than four weeks, instead of five months

• A modified M203 grenade launcher known as the Rapid Additively Manufactured Ballistics Ordnance printed at the Army’s Combat Capabilities Development Command Armaments Center in Picatinny Arsenal, New Jersey

• A concrete bridge printed in 14 hours by a joint Marine Corps–Army team.

But many observers expect AM’s greatest effects to be on logistics and maintenance. Traditional military support models are time consuming, labor intensive, and expensive. According to Lance Bacon of The Marine Corps Times, it can take up to six months and $1 million to fix bulkhead cracks on legacy F/A-18 Hornets. However, with AM, a process using aluminum and 3D printing can bring the cost down to $25,000. Bacon notes: “The Navy has used 3D printing to manufacture obsolete and expensive circuit card clips on Tomahawk missiles; a custom oil line wrench for the MH-60R Seahawk that has saved 80 labor hours per oil change; and a hydraulic manifold for the V-22 Osprey that has a 70-percent reduction in weight, cut fabrication cost by 30 percent, and labor cost by 10 percent.”

In a 2016 Naval Postgraduate School thesis, Marine Corps Captain Matthew Friedell noted some benefits of AM, including shortening the historically vulnerable logistics tail. The Marine Corps “has several vehicles close to the end of their serviceable life that must remain in service for longer due to replacement systems’ unavailability, risking lives,” he explains. He mentions the Swedish-built BV-206 cold-weather tractor, in service since the mid-1980s, writing:

This vehicle was procured with no program of record to acquire parts for maintenance and repair . . . [without which,] units find it difficult to find and purchase parts. These parts are unavailable either because the company that usually manufactures them is no longer in business or simply because the parts are not in production.

With strong advocacy from then–Commandant General Robert Neller, the Marine Corps began introducing AM technology to fleet units in 2017, primarily through Next Generation Logistics initiatives managed by Headquarters Marine Corps. Early tactical fabrication equipment sets consisted primarily of small polymer printers and hand tools to introduce the new technology to Marines with little or no formal technical training.

Formal programmatic introduction of deployable AM began in 2018, when funding was approved for an expeditionary AM equipment lab for use in a medium-forward-deployed environment. The Marine Corps’ XFab combines commercial AM technology with expeditionary requirements, resulting in a full-service 3D printing facility that can operate and survive in arduous deployed locations, the first such formal Department of Defense project of its kind.

The primary technical challenge for XFab is integrating a complete set of additive manufacturing equipment into an expandable, rigid-wall, deployable shelter. AM printers are typically used in carefully crafted, temperature-controlled spaces, because 3D printers are notoriously sensitive to temperature, humidity, shock, vibration, and unconditioned power. (Unconditioned power can fluctuate in voltage and is susceptible to electromagnetic interference from nearby equipment.) If larger parts are desired, then larger, heavier printers (and, in XFab’s case, a laser cutter for post-processing) are needed but not always easily integrated into the constraints of a steel shelter. XFab’s key performance requirement, however, mandates production of functional parts far from strictly controlled professional laboratory environments.

The current XFab set consists of small, medium, and large polymer and blended-material printers, coupled with a large laser cutter, high-performance computers, and an assortment of small hand and post-processing finishing tools. XFab’s present modest capabilities are designed on a modular concept, to allow for future individual hardware and software upgrades without disrupting the system as a whole. Each module is defined by size, weight, and power limits so that printer and component upgrades do not exceed constraints imposed on the overall system. The 8-by-8-by-20-foot expandable shelter is hardwired to accommodate a future metal printing capability, and it is internet-enabled so users can access CAD files remotely and print from anyplace in the world.

The Marine Corps’ additive manufacturing future offers enticing possibilities for warfighters. Supply support infrastructures diminish in proportion to the length of supply lines, a problem known as the last tactical mile. With the right printers and CAD files, Marine Corps machinists could produce replacement weapon parts on demand, with a speed that could mean the difference between mission success and failure and without putting vulnerable ground and air transport at risk—on demand at the point of demand.

XFab’s capabilities have the potential to revolutionize supply chains by allowing Marines to create “one-off” repair parts as well as to prototype and customize new ideas on site while reducing waste, cutting costs, and eliminating the need to wait for a long logistics tail to respond to immediate needs. Instead of carrying countless spare parts into the field, an XFab-equipped Marine battalion could one day simply print many parts only if needed, saving time, money, and—critically—storage.

XFab is still in its infancy. The first system has passed all testing (inclusive of first-article functionality, transportability, and connectivity tests), and the program office will begin fielding initial production systems in 2022. It plans to deploy 16 systems by 2026. System updates, modifications, and improvements will be applied as part of the life-cycle support plan. XFab’s modular design allows for printer upgrades, engineering changes, and planned technology refreshes to mitigate technology obsolescence. The additive manufacturing team at the Naval Surface Warfare Center, Carderock Division, is already planning to integrate a metal-printing capability in the next two to three years. By 2026, XFab should be on par with high-quality industry AM labs, but it also will be deployable and functional anywhere a Marine battalion goes.