Design for additive manufacturing (DfAM) is a critical part of the additive manufacturing (AM) process. In order to extract all the benefits of additive manufacturing it is important to understand the constraints and capabilities of the process and to incorporate those into every design. Using design tools such as Topology Optimization, Generative Design, Architected Materials and parts consolidation, we are able to take full advantage of the design freedom and capabilities of AM technologies.
There are 3 levels of DfAM which widely depend on the degree of development the product or component has already undergone. At SEAM, we work within all three levels of DfAM to help our customers get the most out of our AM technologies.
Level 1: Functional Prototyping for Additive Manufacturing
The first level of DfAM is generally late in the development process and the design has nearly been finalised by the customer. AM at this stage is usually used to quickly generate a functional prototype. There is little to no design freedom at this stage and any changes we make are usually to ensure the part can be printed reliably by understanding the limitations of the AM process being used and following design guidelines such as minimum wall thickness or hole size, residual stress and material shrinkage. The benefit of AM at this level is rapid prototyping, and allows the customer to have a functional prototype to showcase within a very short lead time compared to traditional manufacturing.
Level 2: Modifying for Additive Manufacturing
The second level of DfAM involves modifying an existing design to make use of the capabilities of the AM process. There is more design freedom at this level of DfAM and allows for tools such as topology optimization and architected materials to be used. While the first level of DfAM only aims to make use of rapid prototyping, at the second level of DfAM, we can consider a component’s functional performance and how the capabilities of AM can be used to improve that, whether it be mass reduction or improved thermal performance among other possible performance improvements.
Level 3: True Design for Additive Manufacturing
The third and most advanced level of DfAM involves designing a part from scratch while taking into consideration the capabilities of AM. Here at SEAM we aim to use all the available DfAM tools to extract all the benefits of AM possible to minimise cost and maximise the performance of the component. At this stage, design for mass customization is utilised to optimize parts. An excellent example of DfAM at this level is GE’s Advanced Turboprop airplane engine which has a large portion of its parts produced using AM technologies. As a result, GE designers reduced the parts count of the engine from 855 to just 12 separate parts. This reduction in assembled parts allowed for improved reliability with the engine expecting to run 1,000 hours longer before requiring an overhaul. Along with part consolidation, the engine is 5% lighter which allows the engine to burn 20% less fuel and produce 10% more power. [1]
GE’s Advanced Turboprop Engine is a great example of the benefits of adopting DfAM to fully take advantage of the design freedom AM offers. When incorporated early into the design stage of product development, AM technologies can be used for more than just rapid prototyping but to manufacture end use products that can disrupt the conventional supply chain and assist in solving modern engineering and manufacturing problems.
The added design freedom and customisation AM offers has also opened the door to industries such as fashion and jewellery and to hobbyists, which use the technology to create custom pieces tailored to their own or to their customer’s needs. DfAM benefits aren’t restricted to just engineering solutions, but allow a more creative design freedom to create artwork less restricted by geometric limitations and with precise detail
References
[1] https://www.ge.com/news/reports/mad-props-3d-printed-airplane-engine-will-run-year
About the Author:
Karl Costello Graduated from Waterford Institute of Technology (SETU) with a first class honours degree in Mechanical and Manufacturing . He has experience in working with additive manufacturing processes such as laser powder bed fusion, fused deposition modelling and stereolitography. Karl works as a research assistant engineer in additive manufacturing at SEAM Research Centre .