Additive manufacturing is a technology that enables unprecedented design freedom. Being very different from traditional manufacturing processes, it allows designers to create complex shapes and geometries that would never previously have been possible.
Despite this, not every shape can be 3D printed. To ensure the manufacturability of the design, specific constraints inherent to Additive Manufacturing (AM) need to be addressed. A Design for Additive Manufacturing (DfAM) approach is all about mitigating additive manufacturing constraints as early in the process as possible to ensure products are manufacturable.
To minimise design and lead times, a connected workflow is essential. Hexagon’s new digital reality platform Nexus can help you integrate standalone DfAM applications, allowing real-time collaboration across your teams to turn optimised designs into high performance products.
Here are five tips for designing parts for additive manufacturing:
1. Design for the 3D printing process
Different 3D printing technologies have different limitations and capabilities. For example, Fused Deposition Modelling printers cannot print parts with overhangs beyond a certain angle without additional support structures. On the other hand, Selective Laser Sintering can produce parts with complex geometries and internal structures without the need for support structure. Therefore, it is essential to design parts with the specific 3D printing process in mind.
Manufacturers using generative design for additive manufacturing must take into account the specific characteristics of the printing process, such as material properties, print orientation and support structure. By optimising the design for these factors, generative design can produce stronger, lighter, more efficient parts than those created through traditional design methods while ensuring manufacturability and cost efficiency.
MSC Apex Generative Design empowers makers to create complex structures that only additive processes can manufacture.
Overall, generative design is a powerful tool for creating parts that are optimised for additive manufacturing. For more on how to get the most out of generative design, check out our blog 10 ways you can use generative design to improve your business.
💡Nexus tip: With Nexus DfAM, the user can begin the topology optimisation process by either importing existing CAD data into the MSC Apex Generative Design software or creating a new design from scratch. Design and non-design spaces with associated constraints are then created, and materials can be selected from Materials Connect, our cloud-based material database.
The user must then specify optimisation objectives, such as maximum stress, after which the optimisation can start. MSC Apex Generative Design will automatically generate a mesh and optimise the geometry to create a structure that meets the given constraints and requirements with a smoothed surface for reliable parts.
The user can then convert the optimised geometry into a NURBS-based standard CAD file format with a few clicks for further processing in the common CAD/CAM workflow, without the need for manual rework.
2. Optimise part orientation
The part’s orientation during printing can significantly impact the final product’s quality and strength. For example, if the part is printed flat on the build plate, it will be stronger in the X and Y directions than in the Z direction. Therefore, it is essential to consider the part orientation and print direction to achieve the desired strength and surface finish.
Part orientation will also condition the amount of support structure needed to ensure the printability of the part. It plays an essential role in the process design and associated printing time and cost.
💡Nexus tip: To check and compare the manufacturability of the design candidates, one must first set up the additive manufacturing process for each design candidate. Once the 3D printer model to be used in production is chosen, the user should import the geometry of the design candidate into AM-Studio from CADS Additive. Then part should be accurately placed based on various quality, cost and efficiency criteria.
Additional support structure geometry may be created and improved to guarantee a successful build while avoiding excessive part warping during printing.
3. Virtual process tryout and optimisation
Virtual process tryout and optimisation for DfAM involves using computer simulations to mitigate production issues and finetune the additive manufacturing process before actually producing the part. This can help ensure that the part is produced with the desired quality and that the manufacturing process is as efficient as possible.
To optimise the DfAM process, various factors need to be considered, such as the type of additive manufacturing technology being used, the material, the design of the part and the printing parameters. Computer simulations can predict how changes in these factors will affect the final part quality and can also identify potential issues that may arise during the manufacturing process.
One common approach to virtual process optimisation for DfAM is to use Finite Element Analysis (FEA) simulations. FEA simulations predict how the part will deform during the printing process, which helps optimise the printing parameters to minimise deformation and ensure that the final part meets dimensional tolerances. FEA can also help predict how the part will perform under loading, ensuring the final part meets the required mechanical properties.
Overall, the virtual tryout and optimisation process for DfAM can help ensure that parts are produced with the desired quality and that the manufacturing process is as successful and efficient as possible.
💡Nexus tip: Simufact Additive is a software tool that enables users to model and simulate various aspects of the additive manufacturing process. These include the build process itself, as well as post-treatment operations such as stress-relief heat treatment, baseplate cutting, support removal, and Hot Isostatic Pressure (HIP) treatment. To use Simufact Additive, users first import the outcome of AM-Studio, including the oriented part geometry and the associated support structure geometry.
Next, users define the actual process parameters for the build and post-treatment operations. Once the complete manufacturing process has been defined, the geometry is meshed and the process simulation can begin. This simulation helps to identify potential manufacturing issues, such as the risk of cracks, support failure, recoater collision risk and excessive distortions. Even with proper orientation and support structure, some distortion may still occur. To compensate for this, Simufact Additive can generate a new pre-deformed geometry based on the calculated distortion of the part.
This new geometry anticipates the distortion generated by the 3D printing process and produces a part that falls within tolerance. The software also enables automated global compensation based on a best-fit approach.
For more complex compensation schemes, VGSTUDIO MAX allows users to perform advanced iterative global and local compensations and verify the quality of the result based on the actual product manufacturing information and associated geometric dimensioning and tolerancing (GD&T) plan of the part.
4. Design with material properties in mind
3D printing materials have different properties than traditional manufacturing materials. For example, 3D-printed plastic parts may have lower strength and stiffness than injection-moulded ones, and the orientation of fibre-reinforced materials can be controlled when optimising the deposition toolpath. It is essential to understand the properties of the chosen material and design parts that take advantage of those properties.
💡Nexus tip: Design and non-design spaces with associated constraints are then created, and material is defined and selected from Materials Connect, our cloud-based material database.
Producing complex shapes becomes much easier when designs are optimised to be produced using specific materials and processes.
5. Test and iterate
As with any design process, testing and iteration are critical to achieving the desired results. Product designers should create multiple iterations of the design and test each iteration to evaluate the performance, quality and cost-effectiveness of the part.
💡Nexus tip: Whiteboarding can come in handy for project collaboration because it allows team members to visualise and communicate ideas in real time!
DfAM is a unique approach to product design that leverages the strengths of 3D printing technology. By following the tips above, designers can create parts with complex geometries, custom designs and optimised performance.
Hexagon provides an integrated workflow to optimise part design for additive manufacturing with FEA expertise, ensuring manufacturability and right-first-time printing by mitigating production issues and compensating for part distortion virtually.
This entire workflow can be connected through the Nexus platform for a seamless, collaborative experience that mitigates issues from product design and manufacturability to print job preparation.
We hope you found this post useful. If you’re keen to find out more about the evolution of design see our blog how multiphysics is revolutionising product design.
