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Brennon White is manager of New Technologies, Johnson Controls Automotive Seating (JCI.com). White is also a member of the National Additive Manufacturing Innovation Institute (manufacturing.gov/nnmi_ pilot_institute.html). Not surprising, given the “New Technologies” of his title and his membership, White is deeply involved in finding the ways and means that JCI can implement additive manufacturing (AM).
One of the things that he thinks is essential for engineers to realize is that compared to the past—which is not all that long ago in actual years, but almost a lifetime ago in AM years, as the technology is undergoing rapid development (“This technology is moving faster than Moore’s Law,” White says)—the objects that can be produced with the technology are not necessarily fragile, that they can be both resilient and robust.
“The old adage used to be that you’d make three of them,” White says of printed parts. “One was for your manager to break. One for your customer to break. And one for you to keep, but it would break.”
The breakage is pretty much a non-issue, unless, of course, one produces something that is fragile by design.
White has a bin that was made with selective laser sintering (SLS). It is made with a glass-filled nylon. “I dropped it on a concrete floor from 6 ft. up, and it only has a tiny little dent in it.”
Clearly, kid gloves no longer need be worn when dealing with AM.
Talk to anyone who has involvement in AM and you’re likely to hear a remarkable story before too long. White has one: They needed a metal part. The part, in effect, was to be used as a platform upon which other components were going to be assembled. They needed to see how all of the parts would come together. “It was going to take three months and $50,000,” White says of the metal part. “We came up with a glass-filled nylon solution that took three weeks and cost $4,500.” In addition to the cost and time savings, he points out that it helped the overall development process: “That allowed us to do our development in parallel. Before it would have been done in series, so it saved two to three months.”
At JCI, he explains, they’re using AM techniques for “fit, finish and functional understanding.” White adds: “It helps us solve problems. We can see things that we hadn’t been able to see before—like being able to see in things and through things.” They are, however, trying to figure out how to use it to quickly make prototype tools and molds for production parts. (“We do a lot of stamping, welding and injection molding.”)
White acknowledges that machining technology—subtractive manufacturing— is getting increasingly better. He also says that they’ve found in some instances machining was more cost-effective than additive due primarily to the material costs associated with additive. He thinks that there are a few things that need to happen for AM to become more pervasive, and reductions in material costs are one of them. He points out that for a given plastic material (e.g., ABS), the cost of a filament role is an order of magnitude or so greater than the cost of the material in injection molding style pellets.
(There is something of the chicken-or-egg situation regarding the entrance of big material suppliers into the AM arena, White says. That is, he’s talked with some of those suppliers who say that there needs to be a greater number of machines in the market before it becomes more cost-effective for them to make an entry into the market, but one could assume that the comparatively high cost of the material for AM may be keeping the penetration of equipment into the market lower.)
Another thing that White believes will help proliferate AM is faster processing speeds, and he says that there seems to be a lot of work going on—by industry, academia, and research organizations— that should make this a reality in the not-too-distant future.
“There are things that you can make with additive that you just can’t do with machining,” he says. For example, if you want to make a part with internal feature content, with machining you are likely to have to make two parts and put them together. If you want a part that has features that move relative to one another, then it is either additive or assembly.
But he points out that due to the nature of what they produce at JCI— the aforementioned stamping, welding and injection molding—he’d like to see more work being done in the area of AM with metals.
Beyond changes in materials costs and equipment, White says that engineers must work toward having a different perspective on how products are developed. “The auto industry is already at a cost-effective way of producing things that for us to utilize additive manufacturing for final part production, we have to think completely differently, like taking dozens of parts and making them one part. Most engineers in their 40s and 50s”—and he doesn’t exclude himself— “have to struggle to contemplate that.”
And while he thinks that within five to 10 years when it comes to producing polymer parts people will have to consider whether to go AM or use conventional molding, and that within 10 to 15 years it will be a question of additive or subtractive for metals (though he acknowledges that he may be off in his time estimates—that it may happen sooner), he does say that for the auto industry, it will be more niche vehicle rather than mass production—on the order of 10,000 units per year or less.
An Additive Auto
Although vehicle designers some- times use nature to refer to their designs, it is typically something like a cheetah or a lightning bolt, something signifying speed or sleekness or the like.
But the designers and engineers at EDAG (edag.de) had something else in mind when developing the EDAG GENESIS concept, which was revealed earlier this year at the Geneva Motor Show. They wanted to show the potential of using additive manufacturing (AM) for the development of vehicles, bodies and chassis. They wanted to develop something that would provide strength and stability, with a particular focus on safety. However, there is also the issue of reducing mass, as well. And the result would need to be reasonably aerodynamic, too.
The natural form they based the GENESIS on: the turtle.
What it lacks in sexiness, it makes up for in appropriateness, as the structure is both protective and light, with variable section thicknesses as required.
Personnel from the EDAG Competence Center for Lightweight Construction assessed various AM techniques, including selective laser sintering (SLS), selective laser melting (SLM), stereolithography (SLA), and fused deposition modeling (FDM), for the applicability for the vehicle construction.
They are most interested in FDM, because they find the ability to make complex parts of “almost any size” to be robotically produced without tools or fixtures. While there was concern regarding the strength, stiffness, and energy-absorbing qualities provided by the plastics that are used in AM processes, including FDM, they determined that it is possible to embed carbon fiber material right into the plastic during the FDM process, thereby increasing the required strength and stiffness without having a significant weight penalty.
While the EDAG engineers acknowledge that something like the GENESIS is purely conceptual, they think that given the rapid advances that are occurring in the AM sector, concepts like this may become real within the next 20 years or so.
This is the EDAG GENESIS, a concept produced with FDM.
One of the advantages of additive manufacturing is that it allows the creation of structures with varying thicknesses, thereby providing additional strength where required.
EDAG engineers determined that by including carbon fiber into the plastic material, required stiffness and strength could be achieved in the FDM structures.