A Beginner's Guide to Die Cast Design
Are you new to the die casting process? Learn how to effectively implement design tactics for optimal manufacturability here.
Design for manufacturability
Optimizing your component design to take advantage of the die casting process is the key to seeing a return on your investment. Whether your project is best suited for conventional die casting, multi-slide die casting, or injected metal assembly, it’s best to design your component with the production process in mind. In other words, engineers should approach each project with the intent of designing for optimal manufacturability.
Design for manufacturing (DFM) is a core methodology that ensures that die cast parts perform to specification and reduce the need for secondary operations. Considering that these operations can often represent as much as 80% of the component cost, it’s important to minimize them during the design stage.
DFM is more than just a concept—it’s a way to remove cost and eliminate inefficiencies before your project moves towards production. In this blog, we’ll walk you through three ways to design your die cast component to get the most ROI.
Reduce weight and wall thickness
In die casting, two of your highest cost drivers are the material and the machine time. You can reduce the need for both by adding weight-saving pockets and thinning your walls.
Reducing weight and wall thickness in cross sections may seem like an obvious answer. Less weight means less material, and less material means lower material cost. It also means decreased solidification time, which means that you get more shots per minute. However, some companies find themselves sacrificing performance for cost.
With part performance in mind, it’s important to be deliberate about reducing weight and wall thickness while maintaining part strength. When designing your component, you’ll need to use the mechanical and physical requirements of your project to choose the most appropriate alloy that will perform effectively with thin walls.
For instance, if your part needs to be corrosion-resistant and stable, thin wall aluminum is a good fit. Aluminum is corrosion resistant and retains a high dimensional stability and hardness.
Would you like to learn which alloy is the best fit for your project? Use our dynamic metal selector tool to filter for your required mechanical and physical properties!
Maintain consistent wall thickness
While striving for a reduced wall thickness, it’s perhaps even more important to maintain uniformity. This will go a long way to ensure a consistently stable, repeatable casting that is optimized for manufacturing.
Varying wall thickness can lead to porosity from both varying flow pressures and non-uniform solidification. At Dynacast, our engineers have many tricks to achieve a net-shape component with die casting while maintaining consistent wall thickness.
In Figure 2, you can see that the component on the left has several walls that are much thicker than the thinnest part of the component. If casted this way, it would yield a weaker, porous part. Instead, our engineers will core the thicker walls to achieve more uniformity and incorporate ribs in the cores to guarantee part strength.
Consider draft angle and tolerance zones
When designing your component, it’s important to keep in mind the achievable draft angles and tolerances for your project’s materials to avoid delays in redesigns. For draft angles, in general, 0.5º is achievable for zinc 1º-2º is achievable for aluminum. For exact tolerances, generally between ±0.001” and ±0.002” is possible for zinc, whereas aluminum can hold between ±0.002” and ±0.004”.
With achievable draft angles and tolerances in mind, you’re better equipped to avoid engineering unnecessary cost into the design. Too often, companies will request exacting tolerances and minimal draft angles when such features are not needed to maximize part performance. As a result, their castings fail.
Instead, take a more holistic approach to your design. Determine the non-critical dimensions of your component to allow for more lenient tolerance zones. In addition to extending the life of your tool since there are fewer exact geometries that wear down, allowing for tolerance zones also makes it easier to plan the tolerance stack-up of your entire component. This will help you to avoid machining and secondary operations wherever possible, making your design work for you to get the most out of the die casting process.
Work smarter, not harder
Modifying your part design to take advantage of the die casting process not only enables you to fully leverage the efficiencies of die casting, but can also better suit your business needs.
Are you interested in learning more about how to efficiently design your die cast component for optimal manufacturability? Sign up for our webinar, Work Smarter Not Harder: Removing Cost in the Design Stage.