The answer to this question is not always clear-cut.

Manufacturing Blog: Should You Design for Additive Manufacturing?

Mar 16, 2020

by Todd Grimm

The notion that additive manufacturing offers limitless design possibilities with no process constraints has been largely debunked. Yes, additive opens the door to completely new lines of design thinking and creative configurations. But nobody gets something for nothing—the additive process also imposes limits.

That is why the question, “Should I embrace design for additive manufacturing (DfAM)?” is not as straightforward as it appears. DfAM, a set of best practices to optimize designs for additive manufacturing, seeks to maximize design freedom while minimizing such constraints as time, cost, and manufacturability.

Why wouldn’t everyone embrace that? There are really two answers to that question.

When it comes to designing parts—even traditional ones with a minimum of design changes—that you plan to 3D print, the answer is, “Absolutely.” DfAM is easily the best way to ensure a quality part comes out of the printer and makes it through secondary finishing steps.

But what about when you want to modify a part’s configuration to improve performance? The answer depends on how you plan to make the part and your commitment to mastering DfAM for future projects.
 
Designing for 3D Printing

Additive, like any manufacturing method, has its own rule book for both the process and the secondary operations that follow. Printing an acceptable part is often more complicated than it looks and most designs often require some adjustments.

To produce a part that is functionally equivalent to the original, for example, you might have to modify wall thickness or the diameter of a hole. You must also keep in mind that AM is typically an anisotropic process that is weaker along the Z-axis. Your design must compensate for that and account for other axis-dependent characteristics such as surface quality and dimensional control.


Further Reading: 3D Printing Conformal Molds

For secondary operations, a key consideration is how to remove the support structures needed to build complex pieces. Most AM processes require supports when printing bridges and overhangs, especially those with angles greater than 45 degrees. If your design requires supports that aren’t easily accessible, this secondary process can be difficult or impossible.

It takes time to acquire this type of process knowledge, and that is compounded by the fact that each class of AM technology has its own do’s and don’ts. So, while you may start off with your knowledge of traditionally designed parts, it still takes a serious commitment to acquire the DfAM best practices needed to print them effectively.

The best way to accelerate your education is to immerse yourself in the design and build process to gain firsthand experience. Expose yourself to all the steps and considerations, ask questions, and examine the output. This is the only way DfAM will provide the knowledge you need to create amazing designs for phenomenal performance.
 
Designing for Performance

While there is a growing number of educational resources on the topic, they are not abundant. Besides, mastering DfAM skills is not something that any engineer can address with only a few days of coursework.

Even with experience and classwork, the biggest obstacle to leveraging additive manufacturing lies between our ears. We all start with preconceptions, often fueled by past non-AM experiences, that may impose artificial constraints on our design creativity. To excel at DfAM, we must set our minds free. While liberating, this is a big challenge for most. Not only we must learn new ways of thinking about design, but we must also make time to engage in a try-fail-learn-retry approach.

So, the question of designing for AM becomes “Are you ready to tackle something completely different?”

If you are ready, congratulations. DfAM is a powerful tool for designing for 3D printing.


Further Reading: How Industry 4.0 Impacts Engineering Design

But it is not a solution to every problem, and that’s what I meant when I said the answer was “It depends.” Even if you are ready for the challenge, there is one additional question you should ask yourself: Will your part be produced as an end-use component or assembly?

If the answer is “No”, there is no reason to design for the freedoms that AM offers when a traditional manufacturing process cannot reproduce your elegant, sophisticated, innovative concept.

Yet even if the answer is “No,” engineers need to engage with DfAM. 3D printing is going to play a transformative role in the future of manufacturing. Given the time and effort needed to excel at DfAM, it pays to begin the quest for knowledge and understanding in advance.

Engineers should find opportunities to transition from knowing how to design for 3D printing to understanding how to achieve phenomenal product performance through the new artform known as DfAM.

Todd Grimm is president of T. A. Grimm & Associates, an additive manufacturing consulting and communications company, and a 30-year industry veteran.

Opinions expressed are the author’s and do not necessarily reflect the views of ASME.

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