December 1, 2015
Most of the media buzz around 3D printing/additive manufacturing (AM) technologies has centered on the home or small-shop-based maker. But the biggest driver of what the Wohlers Report estimates to be a $4.1 billion market for AM services and products, has been its integration into traditional manufacturing workflows.
Manufacturers are moving well beyond rapid prototyping (although that is still an important application) and using 3D printing for fixtures, jigs, mold and die creation, tooling, and to create finished parts. That is happening across multiple industries, most notably in auto, aerospace and in the medical/dental markets.
“The accelerated growth that we’ve seen over the last several years has been the adoption of the technology on the production floor, and we see that as being the largest opportunity as we look out over the next five to 10 years,” says Rich Garrity, vice president and general manager of vertical solutions at Stratasys.
In almost all of these use cases, 3D printing has been integrated into existing workflows, augmented by additional processes like machining, forging, molding, etc. “It’s just like having another tool in your toolbox,” says Patrick Dunne, director of industrial 3D printing applications at 3D Systems. “Like any manufacturing process, it will be part of a combination of different tools that are selected to make something.”
It is also changing the way engineers design parts, assemblies and finished products. AM makes it possible to create complex geometries that either would have required multiple pieces in the past, or that weren’t possible at all using traditional processes. Limitations on what can be fabricated are rapidly falling away, and that will require a new approach to design and the ability to incorporate more rapid iteration and optimization processes.
“For subtractive processes, a number of design rules are taught—and those don’t apply to additive manufacturing,” says Andy Snow, senior vice president at EOS. “There is a greater level of freedom of creation.”
3D printing presents two key value propositions when it comes to manufacturing. First, it enables the mass production of custom pieces, although these are not always finished products. Orthodontics manufacturer Invisalign, for example, uses printers from 3D Systems to create thousands of custom aligner models. Those models are used for thermoforming the final dental aligners. “What they are doing is mass custom manufacturing of disposable tooling,” Dunne says. “The largest adopters of 3D printing are not using the printers to make the final product, but are making an intermediate product in the manufacturing process.”
Customization and Complexity
The sweet spot for AM now is in low-volume, high-complexity structures—an extreme example of which is the Strati, the 3D-printed concept car that Local Motors assembled at the International Manufacturing Technology Show (IMTS) in 2014 using the Big Area Additive Manufacturing Machine (BAAM) from Cincinnati Inc. created at Oak Ridge National Laboratory.
The Strati demonstration simultaneously proved the notion that you can print an entire car (minus the tires, the powertrain, and a few other components) and highlighted some of the limitations of the technology. A Toyota factory is unlikely to churn out 50,000 vehicles per year using the same techniques.
But the Strati does represent an economical way to create a completely custom vehicle. Local Motors is turning its attention to what Alex Fiechter, head of product development at Local Motors, refers to as the “nitty gritty” of developing design rules and best practices for the additive processes used on the Strati. There will be more materials testing and crash simulations, for example, as well as investigating different production processes.
“We still have a lot of work to do on our printed vehicle, but it’s very illustrative of what can be done,” Fiechter says. “Even as we look at the possibility of embedding structural elements into the car, it’s a much easier situation for us because we can embed the assisting componentry to create a full, enclosed part as the car is being created. You couldn’t do that with another process.”
Starting next year, GE Aviation will roll out its CFM LEAP engines—the first aircraft engines to include 3D printed parts. In this case: 19 fuel nozzles that the company says could not be produced using traditional techniques. The nozzles are 25% lighter than their predecessors, and will be made in a single piece (compared to the 18 parts previously required). A more intricate design also provides five times higher durability.
That’s a good example of the types of opportunities AM opens up for design iteration and optimization. “There’s almost no correlation between cost and complexity,” Dunne says. “You get step changes in efficiency and optimization of the product itself.”
Manufacturing engineers have traditionally had to compromise on designs to make it possible to fabricate an assembly in a cost-effective manner. 3D printing allows engineers to design for pure functionality and ignore other constraints. “It’s like putting accelerant on design optimization and iteration,” Dunne says. “You can review a concept within hours of designing it.”
Using 3D printing and additional manufacturing processes to complement each other is the way forward, according to Snow at EOS. The company recently partnered with George Fisher Machining Solutions (GFMS) to integrate additive manufacturing machines into the production of mold inserts. “We’re integrating additive into the overall process chain,” Snow says. “We’re integrating what we call the GFMS System 3R approach, which is a highly accurate reference system that links all the machines in a workshop with a common reference, enabling seamless, automated transfers from machine to machine.”
The two companies have introduced the AgieCharmilles AM S 290 system, which produces molds and dies using metal laser sintering. It allows mold makers to move thermal exchange closer to the surface of a mold. It can be integrated with other GFMS machine tools and measuring devices.
Alcoa, a company that has rested its fortunes on traditional manufacturing, is expanding an R&D center in Pennsylvania to accelerate development of 3D printing materials and processes. The company hopes to cash in on demand for complex 3D-printed metal parts for aerospace, automotive, medical, construction and other applications. Alcoa sees the integration of additive and traditional processes as a key strategy, exemplified by its Ampliforge process, which involves printing a near complete part and then treating it with a process like forging to increase part strength. The process is being tested at facilities in Pittsburgh and Cleveland.
Again, the key contribution of AM in these scenarios is the ability to create more complex parts as a single unit. “The power of additive manufacturing really starts in the design process,” Stratasys’ Garrity says. “If a company is looking to just replace a traditionally made part with a printed part with the same design, often it doesn’t make sense.”
Benefits come from freeing up the engineers to design better parts, regardless of the manufacturing process. “You can design structures with lattice interiors to get weight reduction,” Garrity adds. “Aerospace and auto manufacturers are under pressure to meet weight requirements, so that is a big benefit for them.”
Prototypes to Finished Parts
Even the idea of rapid prototyping, a longstanding AM application, is starting to work its way into finished products. According to 3D Systems’ Dunne, automakers are using 3D printed components to help shave time from their go-to-market cycle. The long lead-time on creating injection mold tooling for nylon parts in a vehicle can add weeks to the launch cycle. By printing a run of those parts up front, they can launch the vehicle while the tooling is being produced. “Time is money, so while it’s more expensive to create nylon parts on a laser sintering machine, there’s still an economic justification for that type of bridge tooling because they get to market sooner,” he says.
Jigs, fixtures, tooling and other secondary manufacturing equipment are another key area where 3D printing has flourished. “We see it put ion the production floor to customize jigs or fixtures for a particular line process or for the ergonomic benefits of the line workers,” Garrity says.
In aerospace, composite tooling and molding are allowing manufacturers to create more complex shapes and to more easily change or reproduce those shapes with less investment.
“That also adds to the direct part side of the equation, because that ability to make new geometries has an even larger impact. You are forced or encouraged by the technology re-evaluate how you’ve broken that product up,” Fiechter says.
And the direct part side of the equation is getting bigger. The Airbus A350 XWB uses more than 1,000 3D printed parts, Honeywell International is testing a 3D printed heat exchanger, and GE Aviation, Pratt & Whitney and other companies are also putting printed parts on their planes. AM revenues in aerospace are expected to reach $1.7 billion in 2020 and expand to $3.3 billion in 2022, according to SmarTech Markets Publishing.
The United Launch Alliance, a joint venture of Boeing and Lockheed Martin, is testing additive manufactured parts for rockets. The venture’s Atlas V and Delta IV rockets will include components printed on Stratasys Fortus 900mc equipment with ULTEM 9085 material.
Being able to produce limited access or blind geometries forces engineers to look at the functional duties of every element of a vehicle, for example, and divide those functions differently across a given part. “Instead of an exterior panel simply serving an aesthetic purpose, it can also provide ergonomics and include a body structure for crash absorption,” Fiechter says.
Materials, Education Remain Obstacles
There are still challenges for firms trying to integrate AM on the plant floor. One obstacle is material selection. For some applications, there aren’t always appropriate materials for the existing printing processes, or the processes are too slow.
“There is certainly metallic 3D printing, but the deposition rates are much lower than with polymers, so you butt up against that issue of speed,” Fiechter says. “Cars are built on top of structural steels for safety and crash energy absorption. Now you have to rewrite the book, and find media that can be run through this process with a new type of machine and method of deposition—yet still functionally perform the same way.”
There also needs to be more integration with manufacturing systems, as well as tools to can make it easier for designers to determine which parts make sense for additive.
The biggest barrier, however, is a lack of familiarity among engineers and manufacturing executives. “Designers just need more experience and familiarity with the process,” Garrity says.
EOS has introduced its Additive Manufacturing Consultancy to provide that type of education to clients, including everything from simply introduction to the technology up to a complete assessment of the business. EOS is also working with Underwriters Laboratory on its AM educational efforts.
About the Author
Brian Albright is the editorial director of Digital Engineering. Contact him at [email protected].Follow DE