The aerospace industry, with its stringent certifications, testing, and safety approvals, relies on 3D printing, making a strong case for 3D printing to become a critical part of manufacturing’s future for the rest of us.

Ed Yuh, Project Engineering Manager, Stratasys Direct Manufacturing

3D printing applications in the aerospace industry are a guiding ruler with which to measure the success of the overall 3D printing industry. From giants like GE Aviation relying on metal 3D printing for production components, and Boeing and Airbus boasting thousands of 3D printed parts on its aircrafts, the advances of 3D printing on a production scale have perhaps most boisterously been verified by the aerospace community before trickling down to other industries. Put simply, aerospace usage of 3D printing is a driving force behind industry-wide adoption of 3D printing for production.

We know from the success stories of aerospace production that the payoff from 3D printing isn’t fully realized until you’ve invested in three key areas: training engineers how to design for 3D printing; research and development into standardization of materials and processes; and developing clear parameters for quality control to achieve repeatability.

First, we’ll look at why 3D printing and aerospace get along so well together in the larger manufacturing picture.

The transformation

It’s not surprising 3D printing quickly became a critical solution in aerospace manufacturing so soon after its introduction to shop floors. 3D printing is that rare process that can drastically simplify complex assemblies through consolidation, where multiple parts can be combined into and built as a single component – and often at a much shorter leadtime.

It still offers one of the best solutions for weight reduction because it can cut down on the overall use of fasteners, adhesive and welds, which also reduces potential failure modes associated with joints.

By minimizing assembly processes, 3D printing helps simplify Bill of Material and inventory management – a huge consideration for aircraft supply chain management. There’s also great interest in the idea of a portable and virtual inventory where parts can be printed out on-demand. Overall, 3D printing continues to offer one of the easiest ways to decrease cost and increase productivity by saving weight, time and parts.

NASA’s exploration into 3D printing as an alternative manufacturing method for their rocket injectors is an example of how the technology has reduced manufacturing labor and time. We recently worked with NASA’s Marshall Space Flight Center (MSFC) on a functional prototype injector that originally contained 163 individual components when manufactured with conventional means. With 3D printing, we were able to create those same parts as two-piece functional prototypes that also passed hot fire, static and strenuous mechanical property tests.

But 3D printing can also add complexity where it’s beneficial. We still remember when starting a new project meant hitting the drafting table where it’s easier to stick to straight lines and circles (simpler geometries for simpler fabrication methods.) It’s not wrong to think the only way to ensure a part withstands applied loads is to thicken up the entire design, but today we don’t have to waste material and add weight to get a strong part. 3D printing can grow localized strengthening features using organic inspirations that mimic honeycomb and bone growth in those same areas where stress is concentrated on a design while at the same time removing material in sections with little or no load.

Relying on 3D printing for its organic manufacturing freedom has resulted in a few key areas of manufacturing success for aerospace part design: zero tooling restraints, optimal conformal shapes for improved efficiency/ functionality, and customer design for adaptive technology. At Stratasys Direct Manufacturing, the most common parts we manufacture for aerospace suppliers involve everything from behind the scenes to human interfacing including:

• Full-length, lightweight conformal ducting systems
• Dynamic galley systems
• Decorative parts to resemble chrome-plated metal or wood
• Fuel nozzles
• Sensor housings
• Drain fairings

3D printing is one of the fastest ways to lower costs, part count and weight on a project, which fits many aerospace needs. MRO Aerospace, for example, is evaluating 3D printing for virtual inventory of on-demand parts. However, the technology still has a long way to go, especially in terms of larger adoption. Getting there requires some help from young engineers with a fresh perspective.

New champions for 3D printing

Using 3D printing to its full potential isn’t a matter of simply changing the technology used to manufacture a design. GE’s 2014 jet engine bracket design challenge provides one of the starker contrasts between what 3D printing can do – build a dense part identical to a machined part – and what 3D printing can enable – a re-designed bracket 84% lighter than the traditional model.

The re-designed bracket represents a long-touted ideal in the 3D printing realm: easier iterative design. 3D printing lets you take advantage of a process that builds directly from CAD data where a revision does not mean reprogramming or modifying the tooling and where there is essentially no cost penalty for adding complexity. The winner of GE’s competition was an engineer barely five years out of college who fully understood these principles.

Young engineers today are brought up fluent in digital design programs. They are familiar with 3D printing and aren’t relying on the methodology of converting traditionally manufactured parts into 3D printed parts; instead they are comfortable pushing the envelope. We see young engineers as champions of the technology, in part because they have the freedom and encouragement to test 3D printing’s design limits.

However, the road to 3D printing adoption isn’t filled with young rebel engineers fighting against traditional manufacturing. We need the expertise of engineers who have long worked with tough project challenges to bring 3D printing into fruitful full-scale adoption. However, because 3D printing is only just permeating schools and universities, education in how to use the technology to its full potential is still missing from the larger picture.

Knowledge and quality standardization

Despite the efforts of young 3D printing champions, there are still hurdles to overcome for 3D printing adoption. Education and standard training resources are one example. Another is the need for more production floor personnel with some design knowledge.

While 3D printing has lowered barriers to entry for smaller manufacturers through reduced program development costs and offers an economical way to produce one-off and low volume parts, knowledge on designing for 3D printing is a much larger gap to breach than simply bringing a 3D printer in-house.

Bridging the knowledge gap requires open discussions between manufacturers who are veterans in the field and have developed their own tried and true process parameters for 3D printing. Efforts in developing 3D printing design guidelines and process specifications are fragmented, but have been the focus of larger aerospace companies and 3D printing service providers who supply aircraft parts. As there is no established industry guideline available today that ensures 3D printing processes can reliably produce parts with consistent mechanical characteristics, there is still a “wait and see” approach taken by smaller companies unsure where or how to invest in 3D printing. A grassroots effort by America Makes to spread the technology through education is a step in the right direction, but a broader call to action is still needed.

Getting there (but not quite yet)

America Makes and the American Society for Testing and Materials (ASTM) are currently developing and standardizing terminologies, test methods and process improvements to help companies and users work under consistent 3D printing guidelines. These efforts will eventually result in a well-defined 3D printing space that benefits all industries.

In the meantime, we can look to the aerospace industry in terms of FAA-accepted design allowables, post-processing methods to increase quality, process specifications for repeatability, and the overall successes of aerospace parts manufacturing to know that 3D printing in other industries will eventually be used as a true production option beyond low volume parts. GE, Boeing, Airbus and NASA are a few of many examples where 3D printing has overcome hurdles, such as design, material, and standardization. The wins from aerospace are only the beginning for everyone else. If this sector, with its stringent certifications, testing, and safety approvals, relies on 3D printing, we can comfortably assert 3D printing will be a critical part of manufacturing’s future for the rest of us.

Onward and upward

While some look at 3D printing with disappointment for not achieving as much today as was predicted five years ago, it’s important to step back and look at what it’s achieved in just thirty years. The next steps fall to the community to share information, processes, and successes to bring 3D printing into more widespread adoption. The promise of smarter manufacturing, leaner production, and better products is significant and too good to pass up.

Stratasys Direct Manufacturing
www.stratasysdirect.com