Why Additive Manufacturing Needs the Executive Perspective

This is AM’s cliché: Complexity is free. “We say that a lot—‘complexity is free’—but it really is the thing,” Fletcher says. The most powerful aspect of additive manufacturing for the designer is the freedom to create a complex form—an organic form, a latticed form for weight or material savings, a form with elaborate internal passages, or a single complex form taking the place of what would otherwise be an assembly.

Except, with additive, it is not just that complexity is free. More fundamentally, freedom is free. Design engineers using AM have the freedom to refine, tweak and streamline a new design in nearly every way they can imagine in pursuit of a lower-cost and better-performing product. Other manufacturing processes do not offer this same freedom.

Fletcher says, “Almost any design engineer other than those educated very recently would have had the concept of ‘design for manufacturability’ drilled in.” The capabilities of manufacturing processes have provided the limiting factors for design, and it has fallen to designers to be mindful of manufacturing’s limitations. The most common complaint of manufacturers about designers is failure to respect those constraints. Now, additive manufacturing breaks this set of limitations. It is the first manufacturing process imposing so few limitations related to part geometry.

“Rather than design for manufacturability, additive permits design for functionality,” he says. This is the dramatic change, a change many in manufacturing still struggle to comprehend.

Additive manufacturing permits design for functionality, as in the case of this generatively designed and 3D-printed GM seat bracket. Designing the part via mathematical iteration based on the part’s assembly points and load requirements produced a form offering both 40 percent less mass and 20 percent greater strength compared to the original, conventionally manufactured bracket.

The example pictured here—a generatively designed GM seat bracket—illustrates how this shift might play out. The bracket's elaborate form was refined to reduce weight and consolidate eight separate components into a single 3D-printed piece. How many iterations did designers need to get to this nearly optimal form? They generated 150 options, settling on one with the right combination of light weight and manufacturability.

By contrast, in the past, this exercise would never have been done. A few iterations alone would have brought the design to the point at which the limitations of molding, machining, assembly or some other step would have allowed no further change. Further improvement to the form would simply have added cost by making some manufacturing step too difficult. Thus, the constraints of manufacturing would have determined the design, locking in the limits of performance and the extent of its cost.

But if the design engineer lives within an enterprise employing additive, and therefore knows the component might be made additively, then she is free to spend additional effort tweaking and perfecting the form for minimal material use, minimal weight and minimal manufacturing labor. One more day or two of this designer’s time can bring savings that keep coming for as long as the part is produced. Additive empowers the design engineer to realize as much cost saving as possible before manufacturing begins.

Conventional manufacturing has a big footprint. We don’t question this because until now there has not been any other way. But why is the footprint of manufacturing so big?

It is big because there are many steps. For example, the foundry needs its space. Machining needs its space. Assembly needs its space. And making the tooling for each of these steps is another step in itself that also needs its space. The supply chain accounting for all of this can only cover multiple companies and multiple sites. The supply chain performing these steps can only sprawl.

And the complexity of all this argues for production at large scale, which frequently leads to production in faraway places. The supply chain accounting for the steps listed is sufficiently complicated that when an interlinked set of suppliers proves capable of doing it all well, the reasonable choice is to leverage this proven system by letting it do more rather than trying to pioneer the same complexity with some different set of teams and facilities elsewhere. If a subcontractor overseas can do much of the work inexpensively and deliver good work to the tier-two supplier taking the next step, then let this system continue!

But additive takes away much of the sprawl, and therefore takes away the consequences of the sprawl. A given component made additively does not need a foundry, needs much less machining and might avoid considerable assembly. In other words, all these different steps occur inside of one machine, and inside of that one machine’s compact footprint.

AM has a small footprint, allowing a single machine to take the place of many steps in the supply chain. Engineering and manufacturing firm Roush, a company with origins in the racing industry, 3D printed this aluminum cylinder head. In performance testing, the AM head demonstrated capability and durability equivalent to the conventional head made from casting.

The savings go farther still. AM needs no tooling, so tooling does not have to be made and stored, and the lack of any investment in dedicated tooling makes short production runs and/or mass-customization of the product a much more cost-effective choice.

This small-footprint manufacturing, this manufacturing without sprawl, this supply chain compacted nearly into a single machine—all of this has implications for shipping and logistics. There is potentially far less shipping required as a component cost of manufacturing. But it also has implications for the even more basic matter of where manufacturing occurs. Manufacturing does not have to happen in the locations we associate with industry today. The simplicity of a process based on additive makes it so easy to replicate in other locations that Fletcher says, “If you can get power and employees to any location, it is now reasonable to say you can manufacture there.”

Thus, small manufacturing locations can locate near the markets they serve, cutting shipping cost even further. The only part-specific resources needed to equip these many dispersed manufacturing sites in a single organization are the digital files for the parts these various small sites will produce.

Given the complexity of the standard supply chain connecting various conventional manufacturing steps, “The operations manager today has a pretty complicated life,” Fletcher says. His job entails marshaling complexity, and nearly all his efforts toward making his job more manageable have to do with trying to reduce that complexity.

Fletcher says, “He probably got where he did today by embracing and pursuing concepts such as cellular manufacturing, Kanban, lean.” All are attempts to de-complicate, he notes. All are moves in the direction of what additive manufacturing realizes.

With additive, “preprocessing and postprocessing still exist,” so manufacturing remains a sequence of steps. However, “additive makes the actual processing dramatically easier,” he says. Billet does not have to be sent through a series of machining steps, with the machined part then subject to a series of assembly steps. All the work these steps represent is performed in one operation in one place.

Automation systems manufacturer Kuhn-Stoff redesigned a pneumatic gripper to make it simpler and lighter-weight without affecting its strength. The previous system included aluminum components, fasteners and tubing—21 pieces total. Consolidating these elements into 3D-printed components allowed for a new design consisting of only two pieces.

The savings are numerous when this is achieved, and they are savings in areas the operations manager is painfully aware of. With additive, there is less handling, less work-in-process and less inventory. Moreover, there are fewer human actions to optimize because there are fewer human steps involved.

If the aim of lean is the elimination of non-value-added steps, then additive potentially accomplishes the aim of lean more effectively than a reordering of the plant layout without changing manufacturing steps. And if the aim of cellular manufacturing is consolidating component making and assembly steps for a product into a single space, then additive manufacturing might achieve the aim of cellular manufacturing more effectively than any cell.

This final area of benefit might seem like a small consideration to some. But for the company with a large public profile, it is a meaningful benefit indeed. Manufacturing in a way that is demonstrably conservative of the natural environment and consumable resources, and consistent with stated company principles valuing these things, is another area of positive impact from AM that stands comparably alongside the other areas of savings.

Additive manufacturing is inherently a low-carbon-footprint approach to production, Fletcher says. This is not just because of all the different conventional manufacturing operations potentially consolidated into one. It is also the result of all the transport that no longer has to happen once these steps are merged. That is, if there are no longer separate facilities performing casting, machining and assembly, then there is no longer a need to ship material between them. Among other things, additive manufacturing is a replacement for trucks.

AM is an inherently low-carbon-footprint approach to manufacturing, lending itself to environmental benefits. Airbus's study comparing a cast steel aircraft nacelle hinge bracket with a topology-optimized design 3D printed in titanium measured the differences in resource use and environmental impact. Among the savings: Making the additive part required 75 percent less material, and the part's lighter weight translates to a 40-percent reduction in carbon dioxide emissions associated with this part over its useful life.

That AM is a low-energy process might initially seem questionable. After all, metal is changing from solid to liquid. However, the unit energy required for the additive layering process involving melting is less than the unit energy required to shear away solid metal through a mechanical cutting action. Added to this are all the energy savings from the manufacturing steps that no longer have to be performed.

Additive is also characterized by less material use, a savings realized because of the design freedoms. Less material is designed into the part from the outset, and the near-net-shape realization of the part’s designed form means less material is lost to scrap.

Finally, many of these same benefits are paid forward, because they can be extended to the AM user’s customers. A production process that is founded on AM enables the company’s designers to achieve manufactured products that are lighter-weight, more energy-efficient and more resource-efficient than ever before. That is, not only is AM more environmentally friendly, but the products it makes are measurably so as well. Thus, additive manufacturing becomes a means of helping the companies doing business with the AM user, and even the customers of those companies, to live in line with their own aspirational values.