How to Design for Manufacturability in CNC Machined Parts
- Date:
- Views:26
- Source:RivetPro
For engineers and product developers, designing a part that meets functional requirements is the primary goal. However, ensuring that part is also optimized for costeffective and efficient manufacturing is equally critical. This practice, known as Design for Manufacturability (DFM), is essential for successful CNC machining projects, especially in bulk production. By integrating DFM principles early in the design phase, you can significantly reduce costs, shorten lead times, and improve the overall quality of your machined components.
Here are key DFM principles to consider for your next CNC machining project:
1. Optimize Internal Corner Radii
CNC cutting tools, particularly end mills, are cylindrical and cannot produce sharp internal corners. Specifying a sharp 90degree internal corner will result in a larger radius as the tool passes through. To avoid this, always design internal corners with a radius slightly larger than the intended tool size. A standard practice is to add a radius of at least 1/3 times the pocket depth. This allows for stronger tools and faster machining, eliminating the need for specialized, fragile tools that increase cost and time.
2. Limit the Depth of Cavities
Machining deep cavities or pockets is challenging and timeconsuming. It requires longreach tools that are prone to deflection, vibration, and breakage, which can compromise dimensional accuracy and surface finish. As a rule of thumb, avoid designing pockets with a depth greater than four times their diameter. If a deep feature is unavoidable, consider designing the part as an assembly or using alternative processes like casting for the initial form.
CNC machining
3. Standardize Hole Sizes
Holes are common features, but specifying nonstandard sizes drives up cost. Whenever possible, design holes to standard drill bit sizes. This eliminates the need for timeconsuming boring operations. Additionally, throughholes are preferable to blind holes as they are easier to machine and allow for better chip evacuation. For blind holes, remember that the drill point creates a conical bottom; design the hole depth accordingly.
4. Avoid Unnecessary Thin Walls
Thin walls are fragile and difficult to machine accurately. The vibrations from the cutting process can cause chatter, leading to poor surface finish and potential part failure. To ensure stability and accuracy, maintain a minimum wall thickness. For metals like aluminum, a minimum of 0.8 mm is recommended, while for plastics, it should be at least 1.5 mm. Thicker walls generally lead to a more robust and reliably machined part.
5. Design with Tolerances in Mind
Specifying unnecessarily tight tolerances across an entire part is one of the biggest cost drivers in CNC machining. Tighter tolerances require slower machining speeds, multiple finishing passes, and more precise inspection, all of which increase price. Apply tight tolerances only to critical features and interfaces, and use standard tolerances for noncritical areas.
Partner with a Manufacturing Expert
The most effective way to implement DFM is to collaborate with your manufacturing partner early in the design process. A seasoned CNC machining factory can provide invaluable feedback on your designs, suggesting modifications that enhance manufacturability without compromising function.
At our onestop CNC machining factory, we specialize in transforming complex designs into highquality,批量produced parts. Our engineering team is ready to work with you to apply these DFM principles, ensuring your project is not only successful but also optimized for costefficiency and speed from prototype to fullscale production. Contact us today for a free DFM analysis on your next project.