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Df(X)AM : A Call for a More Nuanced Understanding of Design for AM
And an invitation to share design strategies for each additive manufacturing process.
Each additive manufacturing process requires a different design strategy, it is time to share and compare those strategies along with the constraints and potential for each specific technology.
The American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing”, formulated a set of standards that classify the range of Additive Manufacturing processes into seven major categories (Standard Terminology for Additive Manufacturing Technologies, 2012).
Powder Bed Fusion
Directed Energy Deposition
Within these seven major categories there are a number of variations based on the specific manufacturing process, materials and post processing. The manufacturing process also includes the digital pre-processing and in-situ modifications that also influence the manufacturing constraints, and freedoms giving us even more diversity, and then we have hybrid additive, subtractive, composites and coating that add even more complexity to the mix.
Our umbrella term for additive manufacturing is now stretched so thin to cover such a wide array of possibilities that it starts to lose meaning in describing the processes and possibilities. The term DfAM is similarly so broad as to only guide us in a general direction, but not specific enough to really describe the thinking and strategy required to design for a specific AM process.
It is a positive step forward that both educational institutions and workplace development programs are emerging to teach designers and engineers the DfAM fundamentals there is also a requirement for deep dives into specific manufacturing processes. While having an understanding of orientation and support structures for polymer FDM may help someone design for, orient and support a titanium component for LPBF, the mechanical physics and thermal constraints are wildly different and the economics are orders of magnitude apart.
Many hardware manufacturers already have education initiatives in place driven by the simple economics of failed parts equals unhappy customers and to truly derive the most value from their machines their customers need to become experts at designing for that specific process, down to the machine, parameters, materials, post process and inspection.
Educational institutions who have invested in a particular additive hardware system also naturally build up expertise in their faculty and students on the nuances of those particular systems they have direct access to which those students them bring to industry.
Both of these instances are the natural evolution of education and the development of expertise but as previously addressed there are seven major additive technologies and wide variance within each of them. An understanding of DfAM for one of the technologies, machine or material does not always carry over to others, even within a specific category.
There is a need to expand awareness around the different design constraints and opportunities for each of the additive manufacturing processes beyond simple guidelines. While ‘design rules’ such as the chart developed by hubs is a great start, it is by no means comprehensive and needs to be expanded for designers and engineers to design not just for manufacturability, but also for the particular performance of each material and process.
To help spread awareness about the different design constraints and opportunities for each process, I invite people/companies to share the design constraints, opportunities and philosophy for their manufacturing process of expertise.
Contact us via email@example.com to discuss if you are interested in contributing to help broaden awareness for each particular flavor of Df(X)AM.
To be clear, we need to move beyond generic DfAM guides of X° angle overhang, standard minimum wall thickness and tolerances and talk about the specifics for each process. The design strategies that deal not only with the manufacturability of each process, but also the particular performance gains possible through design, materials and process.
We also need to find a balance between the necessary conservatism of service bureau design guides (failed prints cost them money, not the customer) and the overstatements that sometimes come out of marketing that either exaggerate or does not understand the true constraints and possibilities of the systems they promote.
Please reach out to firstname.lastname@example.org if you are willing to contribute.