Optimizing Your Design for CNC Machining: Tips for Engineers
CNC design optimization involves refining part designs to improve manufacturability, reduce production time, and lower costs while maintaining or enhancing product quality. This approach considers various aspects of the CNC machining process during the design phase to create efficient parts that produce and meet functional requirements. These integrated design and engineering approaches result in more efficient manufacturing processes.
Geometric Complexity
Complex shapes generally lead to higher machining costs, as intricate geometries require longer machining times. Complex parts could necessitate multiple machining operations, slower cutting speeds, or more frequent tool changes. They might also require more sophisticated CNC machines with higher operational costs, such as 5-axis machine tools.
At Macfab, we encourage collaboration between design engineers and CNC machinists to streamline complex designs and control costs on CNC machined parts.
Tool Access and Part Features
Design elements like deep pockets or thin walls increase machining costs and lead times. Excessive cavity depths require specialized tooling, and thin walls need special techniques and slower machining speeds. Both add significant costs to a machining project.
Macfab’s design experience allows us to provide feedback to help clients optimize their designs for manufacturability. We understand tools have a limited cutting length, and limiting the depth of cavities minimizes tool deflection and enables holding tight tolerances while improving surface finish.
CNC Design Optimization
When designers incorporate multiple components into a single part, they almost always increase complexity, making it more challenging to machine efficiently. Conversely, sometimes, the most minor adjustment to a design is the simplest and most cost-effective solution.
For example, recently, a client needed a hex in the back of ten 1/4″-20 screws for prototyping. Although they were considering broaching or EDM, two rather expensive options, to accomplish this, we suggested providing enough corner relief in the design to allow machining the hex.
The client got the prototypes quickly and held down their costs.
Material Considerations
Although choosing a material according to the needs of the component is essential, it also makes sense to consider the cost. Some alloys can be twice the price of others because of their chemistry, so you should consider if the lower-priced stock will work equally well for your needs.
Engineers working with CNC specialists during the material selection phase can offer suggestions that save material costs and machining time.
For instance, consider the raw stock. If you design a part to be .75″ thick, that’s a standard bar stock size, meaning you must machine it from 1″ stock and mill it down to the finished thickness. However, if you can design that component to be .65″ thick, you can use .75″ stock, saving on labour and material costs.
Considerations for CNC Manufacturing
To shift from product design to design for production, consider the following design strategies:
- Reduce part complexity when it doesn’t compromise functionality.
- Optimize designs for easier machining by maximizing the size of internal features to allow for larger cutting tools.
- Avoid thin walls and deep cavities that require special techniques and slower machining speeds.
- Choose materials that are easier to machine when possible, as this can reduce tooling wear and machining time.
- To facilitate efficient CNC machining, specify adequate radii in corners, looser tolerances whenever possible, and different surface finishes on various faces.
Conclusion
Balancing design intent with production needs ensures a seamless pathway from concept to creation. Transitioning from product design to production design requires embracing manufacturability. Designers can enhance CNC machining efficiency by accommodating material limitations, ensuring sufficient wall thickness, and optimizing pocket depths. Early in the design process, engage a CNC machining expert, like those at Macfab, to help you optimize your designs for CNC machining. They will ensure the potential for reduced costs and improved production efficiency.
However, it’s important to note that not all projects can be perfectly optimized for the most ideal settings. Every design comes with its unique challenges and constraints. At Macfab, we thrive on tackling these complexities, helping clients navigate through the most difficult hurdles, and optimizing designs to give you the best chance at success. Whether you’re dealing with intricate geometries or tough material choices, we’re here to find practical solutions and bring your ideas to life.
