Small design changes can significantly impact production cost and lead time. Learn how to optimize wall thickness, avoid sharp internal corners, and select the right tolerances for your CNC-machined parts with Sundar Industries.
DFM is a systematic approach to designing parts that are easy and cost-effective to manufacture. For CNC machining, even minor adjustments to your CAD model can result in significant savings — often without affecting the part’s performance.
Here are seven practical tips to improve the manufacturability of your CNC parts, recommended by the engineering team at Sundar Industries:
Avoid Sharp Internal Corners: A sharp internal corner requires a very small tool, which is slower and more prone to breakage. Adding a radius (at least 1/3 of the cavity depth) allows for larger, more rigid tools and reduces machining time.
Minimize Deep Cavities: Deep cavities (more than 3-4 times the tool diameter) require specialized tooling and extended machining time. Consider reducing depth or adding draft angles.
Optimize Wall Thickness: Thin walls are prone to vibration and distortion during machining. For metals, maintain a minimum of 0.020 inches (0.5mm); for plastics, 0.030 inches (0.75mm) is recommended.
Design with Standard Tool Sizes: Use hole sizes, radii, and thread sizes that match standard cutting tools. Custom tools add cost and lead time.
Limit Tight Tolerances: Specify tight tolerances (±0.005mm) only on features where they are truly necessary. Tolerances that are too tight require slower machining, more setups, and special inspection, driving up cost.
Reduce Setup Complexity: Features that require multiple setups or index positions add cost. Whenever possible, design parts to be machined in as few setups as possible — preferably one.
Include a Clear Datum Surface: A well-defined datum provides a reliable reference for measurement and alignment during machining, ensuring consistent quality across parts.
By applying these principles early in the design phase, you can reduce machining time, lower production costs, and accelerate time to market. At Sundar Industries, we provide free DFM feedback on every CAD submission to help you optimize your design before production begins.
