Print This! Additive Manufacturing Is Becoming a Key Capability

Photo by MC3 Christopher A. Veloicaza

AS THE DEMAND FOR FASTER PROTOTYPING AND LESS-EXPENSIVE REPLACEMENT PARTS GROWS, SPACE AND NAVAL WARFARE SYSTEMS CENTER ATLANTIC IS EXPANDING ITS CAPACITY FOR ADDITIVE MANUFACTURING.

By Diane Owens

A research-and-development scientist at Space and Naval Warfare Systems Center (SSC) Atlantic wanted to create a compact, energy-harvesting support component not available commercially. He designed the component in computer-aided design software and, in a single day, used additive manufacturing (also known as 3D printing) to build a prototype of the product at minimal cost. After determining that the form, fit, and function of the initial prototype needed a few adjustments, he modified the original design and built a second component that met exact requirements.

On board a submarine, a keyboard video mouse switch had a high failure rate because of a substandard button design. Two sets of four buttons continuously broke under daily use on this submarine and in every common submarine radio room in the fleet. To resolve the issue, SSC Atlantic personnel reverse engineered the buttons and built them with a strengthened design using additive manufacturing. After fit testing, they contracted with an outside vendor to manufacture the buttons in a large quantity using a heavy-duty polymer. Depot employees then repaired the faulty units and the enhanced buttons were installed to meet fleet requirements.

These are just a few of the ways SSC Atlantic employees leverage additive manufacturing technology to save time and money throughout the engineering life cycle from research and development through maintenance and sustainment. This innovative technique provides optimal support to the fleet by putting the best information warfare solutions in the hands of warfighters.

“Additive manufacturing further enables SSC Atlantic to improve cost, schedule and performance in delivering and sustaining solutions to the warfighter in an environment where change is constant,” said Chris Miller, SSC Atlantic’s executive director. “It fundamentally changes how we think about manufacturing, enabling us to be more responsive and meet our commitments.”

Traditional vs. Additive Manufacturing

Traditional production processes use subtractive manufacturing: a chunk of raw material, like metal or plastic, is milled using lathes and other equipment to extract pieces, leaving the final product. It often results in substantial material waste. Additive manufacturing builds a product from scratch, in layers, based on a computer-aided design drawing with precise product specifications. The 3D printer build-plates are heated so the product adheres to them, and the raw material, generally one of various types of plastic filament, is heated and flows through tubing where it is compressed and extruded in a liquefied form through a nozzle. It is then distributed onto the printer bed in a fine layer and the nozzle oscillates across the build bed continuously until the product is complete. Depending on requirements, some plastic materials create rigid products, while others are flexible.

Because all products are tacky (sticky) when completed, they must cool until they harden. Therefore, designs for some 3D-printed objects contain built-in support posts to lift part of the object and support it during cooling. The posts are removed when the product hardens and the connection points are sanded.

Solid 3D products result from numerous passes of layers of material continuously dispersed across the designated area on the build bed. Infilled 3D-printed products have various patterns printed inside, such as honeycombs or triangles. Infill is created by printing a layer of plastic, then inserting a layer of air. Alternating layers of plastic and air result in open spaces in various patterns. The percentage of infill affects product weight, strength, and print time; infill also can be used for decorative purposes. Generally, the higher the percentage of infill, the stronger the product is.

Handles, knobs, and other appendages can be included in the basic design, eliminating the need to build them separately and connect them after the product is complete.

Although additive manufacturing can take hours, or even a week, to build a product, it is much faster than researching commercial product availability, creating and submitting contracting documents, soliciting bids, selecting a vendor, sending specs to a manufacturer, and waiting for the product to arrive. It is also much cheaper.

Modifications and Research and Development

If products created using traditional manufacturing do not possess exactly the right form, fit, and function, the design must be altered and updated drawings and contracting modification documents are sent to the manufacturer, which must create a new product or modify the existing product. The process might need to be repeated several times before the product is fully functional, and each modification costs time and money.

Additive manufacturing allows for design modification, editing of software drawings, and on-site building of modified products at a tremendously lower cost and in less time. New products and replacement parts—often reengineered to eliminate flaws, increase durability and reduce the number of connecting pieces—are generally created from low-cost durable plastics. Other materials, such as steel, titanium, bronze, brass, silver, gold, aluminum, wax, metal-infused plastic, and rubberized plastic, also can be used as needed.

Using additive manufacturing technology, a prototype of a product can be built once the design is conceptualized and tested to ensure it meets all constraints. Additional runs allow the design to be refined and improved.

In addition to producing an energy harvesting support component, science and technology employees at SSC Atlantic also developed an idea for a spherical-shaped intelligence and surveillance product. They designed the product in two interconnecting pieces, built it in a 3D printer, and placed an embedded system with sensors inside. Providing a prototype to military sponsors is immeasurably more effective than presenting a white paper.

Preproduction

Additive manufacturing also has enhanced capabilities in the preproduction phase, which starts with identifying a need for a product and generally ends with creation of a prototype.

SSC Atlantic preproduction employees designed and built an additive manufacturing prototype of a rack required by a customer to hold an intercom component. Numerous design iterations were built because of changing requirements, and the final version of the rack was installed to verify form and fit. Product specifications were sent to a vendor and the racks were produced in large quantities, saving a considerable amount of time and money on prototyping. This flexibility would not have been possible with traditional manufacturing methods because of metal fabrication lead times.

When employees integrate command, control, communication, computers, intelligence, surveillance, reconnaissance equipment in military land vehicles, it often involves designing mounting solutions to hold sensitive equipment in place. The team was tasked with designing a bracket to secure cryptographic equipment in a vehicle. However, crypto equipment has security sensibilities and can only be used in a secure lab or signed out for use under secure conditions.

The team’s solution was to use additive manufacturing to design and build a full-sized plastic replica of the crypto equipment exterior, and to design and build the bracket to hold it. They were able to test form and fit, make necessary modifications and complete the project without delay in an open environment.

In other situations, the team must design mounting solutions for commercial off-the-shelf products that are not available because of vendor back orders. The team requests a computer-aided design model of the product from the vendor to determine the size, weight, connection layout and mounting interface patterns. They can then build a full-sized replica to design and build the mount required before the product arrives.

Preproduction employees built and used a system integrated lab (SIL) to analyze and test system equipment for the Joint Light Tactical Vehicle. Because components have exposed electrical contacts, the team used additive manufacturing to design and build a 3D safety cover to protect technicians and operators from electrical shocks when reaching around the SIL components. This proved to be an inexpensive solution to a potentially dangerous situation.

SSC Atlantic employee Josh Heller, left, reviews computer-aided design software created for additive manufacturing, while Ryan Wilhite verifies the printer is properly calibrated. Photo by Joe Bullinger

Production

During the production stage, when raw materials are transformed into a product, SSC Atlantic employees were tasked to design and create a protective case for a specific personal computer. The original case contained 13 interconnecting pieces. The team created a 3D scale model of a case from rugged plastic and designed a hooked Plexiglas top and bottom for it. After the customer approved it, they created a full-sized model built with only two pieces, instead of 13, for approximately $30.

On another occasion, employees needed to improve an existing metal cable support bracket attached to the back of a piece of submarine equipment. The cables continuously sagged and caught on a nearby alert panel, disconnecting the power or damaging the intricate cable assembly. An enhanced design was drawn on a napkin in 30 minutes, input into design software in an hour, printed on rugged plastic in a 3D printer in 48 minutes, and fitted and tested with the equipment in 20 minutes. The resulting product confirmed the solution and led to revisions to the metal bracket.

Maintenance and Sustainment

SSC Atlantic operates a maintenance depot where employees repair circuit boards and equipment used by the fleet and other Navy entities. Maintaining and sustaining equipment entails a considerable amount of reverse engineering. Because repair and maintenance work often uncovers product flaws, additive manufacturing technology is extremely helpful in duplicating and modifying products to enhance function. Employees can hand-scan an object to generate continuous images or scan it on a rotating bed, which creates a software design for that item.

As part of one project, depot employees had to replicate a failed power supply on an obsolete product with components covered in tacky plastic. To buy a comparable new product required a minimum purchase of 10 items at $2,000 each. Rather than incur a $20,000 expense, they painstakingly peeled the plastic potting away with tweezers, redesigned the object and printed new parts on a 3D printer. They replaced more than 100 components in the product and the modified power supply has never failed.

By combining the expertise of its workforce and additive manufacturing capabilities, SSC Atlantic continues to move to the next level of repair and redesign needed to keep Navy systems functioning. Employees are creating rapid prototypes of innovative new products, duplicating existing products inexpensively, and enhancing existing design quickly and easily. By building lighter, cheaper and more effective parts to replace those that are no longer commercially available, SSC Atlantic is putting information warfare solutions in the hands of warfighters quickly, creatively, and cost-effectively.

About the author:

Diane Owens is a writer with Space and Naval Warfare Systems Center Atlantic public affairs.