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Aurora Flight Sciences, a developer and manufacturer of advanced, unmanned systems and aerospace vehicles, collaborated with the Massachusetts Institute of Technology (MIT) and Pratt & Whitney to evaluate the potential of a Subsonic Fixed Wing transport aircraft for a NASA Aeronautics Research Mission Directorate concept study, called N+3. RedEye, the additive manufacturing services division of Stratasys, worked with Aurora to design and create model parts to be tested in NASA Langley Research Center's 14 x 22-ft wind tunnel.

3-D printing in aerospace: not just winging it

The demand for innovative manufacturing technology that produces lighter parts with stronger material grows each day in the competitive aerospace industry. 3-D printing, also known as “additive manufacturing,” is at the center of this innovation, with major original equipment manufacturers and the U.S. Department of Defense investing heavily in this rapidly evolving technology to save time and money.

There are three major ways in which the industry is applying 3-D printing today.

Validate a design

3-D printing allows engineers to test and make design adjustments without the capital investment in hard tooling. The technology builds the part from the ground up, layer by layer from a CAD file without a mold. Updating the design is as simple as modifying the design file and printing the new part. This means aerospace companies, which often have low production volumes, are not excessively penalized for minor design changes.

Tooling generates the majority of costs in producing aerospace parts. If a part’s dimensions are just slightly off—a fraction too long, etc.—then the tool must be altered or even rebuilt, increasing costs and extending the production timeline. These potential pitfalls are motivating companies to migrate to 3-D printing during the testing phase to validate the design, produce low-volume end-use parts, and apply tooling when they need higher volumes of one part.

Use of 3-D printing helps minimize risk and reduce costs while significantly decreasing lead time, speeding up and further enabling innovation during form, fit, and function tests. The ability to simplify production, and reduce its costs in the process, is a major reason why the largest aerospace OEMs are adopting 3-D printing at a rapid rate.

A weighty trend: getting lighter

A major goal for aerospace companies is reducing aircraft weight. 3-D printing is vital to aerospace in this regard, as a majority of parts created through the technology are composed of industrial-grade FST plastic as opposed to heavier metals. 3-D printed parts can also be designed and built with complex geometries optimized for weight efficiency—geometries with cavities and overhangs that would be impossible to build with traditional manufacturing methods.

The biggest difference plastic 3-D printed parts can make are on non-flight-critical parts, such as cockpit or lavatory pieces. By 3-D printing interior parts, aerospace OEMs can take advantage of the time and cost savings associated with the technology while reducing weight in a manner that doesn’t compromise tolerance or safety.

To give these parts even more aesthetic versatility, some are now being put through a process that applies a thin layer of film with customized finishes, like natural hardwood and chrome. This technique makes the part nearly identical to those made from traditional manufacturing methods, only they are lighter and cheaper to produce.

JIT Inventory

A major issue in aerospace is inventorying aftermarket parts for the entire life of an aircraft. OEMs are required to inventory parts that may sit on the shelf for many years without use. This ties up capital and increases inventory-management costs.

3-D printing enables just-in-time inventory (JIT), which means parts that aren’t flight-critical (e.g., non-load-bearing or non-mission-essential parts) are built on demand as needed, rather than stocked in a warehouse awaiting future use. Global 3-D printing service providers have the mechanisms in place and the capacity to even build higher volumes of one part on demand. Instead of shipping inventory across the globe, aerospace companies can send replacement part design files to a global service bureau and have the parts printed at the factory nearest to the production facility.

An eye towards the future

Simplifying the production process, reducing weight, and offering JIT inventory are just the tip of the iceberg in terms of 3-D printing applications and trends in aerospace. Soon, optimizing electrical components via additive manufacturing, combined with laser direct structuring (LDS), may offer additional time, cost, and labor savings through laser-imaging and plating to form metallization on FDM parts for applications like antennas and interconnects. In addition, new materials are on the horizon that, through greater heat tolerances and increased strength, will expand the possibilities for 3-D printed aircraft parts.

Another application aerospace companies are starting to take advantage of is 3-D printing manufacturing tools, such as jigs and fixtures. Manufacturing tools are used to align, assemble, clamp, and calibrate components during stages of the manufacturing process. To avoid production delays, new manufacturing tools must be rapidly designed, manufactured, and implemented. With 3-D printing, lead times can be reduced by 40 to 80% and cost can be reduced by 70 to 95%. The design freedom you gain with 3-D printing also allows for improved function and ergonomics in manufacturing tools, to build more effective designs.

With significant advancements in the last decade, 3-D printing in aerospace has a bright future. It will be exciting to see where it takes off to next.

Joel Smith, Strategic Account Manager for aerospace and defense at RedEye, by Stratasys, one of the world’s largest providers of additive manufacturing services, wrote this article for Aerospace Engineering.

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