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Design Rules for AM

August 11, 2019

Filed under: 3D printing,additive manufacturing,CAD/CAM/CAE — Terry Wohlers @ 09:57

Little by little, companies are learning that it can be very different to design for additive manufacturing (DfAM). To make AM economical for production quantities, DfAM is usually necessary. As costs of the machines, materials, and post-processing are driven downward over time, this may change in some instances. For the foreseeable future, DfAM is not only useful, it’s a requirement.

When considering DfAM, we often think of using topology optimization, lattice structures, and other methods to reduce material and weight and potentially improve part functionality. Just as important are design rules and guidelines to reduce trial ‘n error among engineers and designers. This information usually comes from experience and tribal knowledge among very few at a company.

The previous guitar stand was designed by Olaf Diegel, an associate consultant and DfAM instructor at Wohlers Associates. The stand is cleverly designed to fold and unfold, as shown. The large hinge depicted at the left requires a surface gap of 0.4 mm (0.016 inch) for it to operate so that it is not too tight or lose. A smaller hinge, shown in the center, requires a gap of 0.3 mm (0.012 inch) because the rotating surface area is much less. Making the gap larger would result in a hinge that’s too lose.

Olaf has learned many rules and guidelines from his extensive experience with DfAM, AM, and post-processing parts. They often differ from process to process and material to material. Many of these methods of DfAM will be discussed at a special three-day DfAM course in Frisco, Colorado next month. If you’re transitioning to AM for production applications, you or your colleagues may want to attend this training. It could save your organization months or longer and help you determine if/when a part or assembly is a good candidate to produce by AM.