How to effectively Design for Additive Manufacturing

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1 How to effectively Design for Additive Manufacturing In recent years, Additive Manufacturing has firmly settled in the minds of technology leaders and innovators all over the world as potentially the most disruptive technology of the young century. A lot of questions however are still left to be answered about the next big step towards the implementation of serial AM production within those companies. In the following article I would like to give a small insight into enabling the minds of engineers and designers with the objective to get the highest value out of where the whole process begins - product development. A quick sketch representing the EOS Workflow for successful and quick part design. Illustrations 2018 Nick Loth Whether your aim is to redesign an existing application that has already successfully been identified for its AM potential (think lightweight, mass customized, highly complex) or you set off to design an entirely new

2 product that includes some, or ideally, all of the value-adds of AM, where do you actually start? Anyone who is familiar with traditional product development processes has probably heard of IDEO S Design Thinking, which has proven to be a highly efficient method in finding an adequate solution to a problem in a short, yet very productive amount of time. Environmental issues such as intelligent and efficient utilization of scarce resources as well as consistently growing markets only seem to accelerate the speed and need of innovation to stay competitive. Combining Design Thinking and Additive Manufacturing together to achieve exactly this makes perfect sense. As a matter of fact, Design Thinking preaches to come up with a viable prototype as quickly as possible. This way, inherent flaws and even showstoppers in a product may be discovered and mitigated at a much earlier stage. Luckily for us, 3D Printing originated asand still is - a speedy and cost-effective prototyping technology. Just because we are now able to manufacture end-use parts doesn t mean that we have to stop prototyping them the same way we always did. I would like to briefly go through the separate steps of this redesign methodology to give a better understanding of what the workflow encompasses. The journey begins in the so- called Concept Phase, during which we are still free in our design choices and directions that we want to explore, but only have a limited level of knowledge for this specific application. Throughout the timeline of the project, our freedom of design will constantly be narrowed down, while our level of knowledge will steadily increase. Clarify Relevant Requirements Identify and prioritize the requirements for the selected application, this can be done via numerous approaches and is specify to one's own experiences and preferences. Define the production process chain ( e.g. need for powder removal, post- machining, support removal and so on). This will help you

3 immensely in identifying potential issues that may require alterations of the final geometry later on. Generate Concepts Research and ideate concepts that will tackle and solve the previously defined requirements of the part. A source of great potential for innovation can be mother nature in the form of biomimicry. After all, it has had a 4.5 billion year head start. Test Concepts Now is the time to make use of the advantages and speed of AM and put those concepts to the test. At this stage in the process you may have come up with some interesting design features. Produce them; create multiple versions to test for buildability, cost optimization and to analyze for quality requirements. Nothing beats a physical model.

4 Decide After some rigorous testing of the concepts and their critical features, you will now have a clear idea of what the final design will look like. If you don't, loop back to the previous steps and iterate until you are satisfied with the outcome. Your production process chain is well defined and adapted to the design geometry. Decide on Final Orientation The build orientation of an AM part is what differentiates it from more traditional manufacturing technologies. It has a tremendous impact on buildability, quality and cost of the part. During the clarification and ideation stages you will figure out an orientation that best suits your specific product, as it will most likely involve trade- offs between different features.

5 Prototype At this point we have left the Concept Phase of the design process and moved into the Detail Phase, with a clear design in mind. Generate the final geometry of your product according to the concept and orientation decision; there should be no more major surprises and findings. Fine-Tune Now is the chance to validate the generated geometry and to do some minor adaptions considering the design rules for AM. As is the case with SLS and DMLS technologies, you may at this point adapt your laser parameter sets to further increase productivity and buildability of the part. Another great way for build success validation can be the use of process simulation software such as Amphyon by additiveworks. It is a powerful tool to evaluate optimal supports, calculate potential residual stresses and apply pre-deformation to increase the yield of successfully built, dimensionally accurate parts.

6 Feedback Manufacture, post- process and test your final design. Does it tick all the boxes? Has something been overlooked due to a lack of information or communication? Write down your findings and evaluate the next steps of the project. If everything worked perfectly the first time, the task may now be finished. A lot of the time however there is still potential for improvement, which is great. This means the product will be even more refined during another round of prototyping and testing. The great advantage is, that you didn t spend months on end on just that one design, but you probably have a stack of ideas and concepts that you can draw from. The creative and time-saving potential of Design Thinking together with AM s quick prototyping potential and almost unlimited freedom of design fit together perfectly and become a powerful tool for today's engineers. In order to achieve radical innovation with new technologies, we have to make sure, that the rule books of how to achieve exactly that will have to be rewritten as well.