14 Proven Design Tips to Reduce the Cost of CNC Machining

1. Minimize Material Waste:

• Choose the Right Material Size: Select stock material sizes that are as close as possible to the final dimensions of your part. This reduces the amount of material that needs to be removed during machining, saving both material costs and machining time.

• Nest Parts Efficiently: If you're producing multiple parts, arrange them on the material stock in a way that minimizes waste. Consider using nesting software to optimize part placement.

2. Simplify Geometry:

• Reduce Complex Features: Complex geometries, such as deep pockets, thin walls, and intricate contours, require more machining time and specialized tools. Simplify your design by eliminating unnecessary features or combining multiple features into simpler shapes.

• Use Standard Features: Whenever possible, use standard hole sizes, radii, and other features. This allows the use of standard tooling, reducing setup time and cost.

• Avoid Sharp Internal Corners: Sharp internal corners require small tools and multiple passes, increasing machining time. Use radii in internal corners to allow for larger tools and faster machining.

3. Optimize for Machining:

• Design for Easy Fixturing: Ensure your part can be securely held during machining. Avoid designs that require complex or custom fixtures, which add to the cost.

• Minimize Tool Changes: Design your part so that as many features as possible can be machined with the same tool. This reduces the number of tool changes required, saving time and money.

• Consider Machining Direction: Design your part so that as many features as possible can be machined from the same direction. This minimizes the number of times the part needs to be repositioned, reducing setup time.

4. Choose the Right Tolerances:

• Avoid Over-Tolerancing: Specify tolerances that are as loose as possible while still meeting the functional requirements of your part. Tighter tolerances require more precise machining, increasing cost.

• Use Geometric Dimensioning and Tolerancing (GD&T): GD&T allows you to specify tolerances more precisely, which can help to reduce costs by ensuring that only critical features are tightly controlled.

5. Consider Alternative Manufacturing Methods:

• Combine CNC Machining with Other Processes: For some parts, it may be more cost-effective to combine CNC machining with other manufacturing processes, such as casting, forging, or 3D printing.

• Explore Different Materials: Some materials are more expensive to machine than others. Consider alternative materials that may be more cost-effective while still meeting your performance requirements.

6. Design for Manufacturability (DFM):

• Consult with Your Machinist Early: Involve your CNC machinist in the design process as early as possible. They can provide valuable feedback on how to optimize your design for manufacturability and cost-effectiveness.

• Use DFM Software: There are software tools available that can help you analyze your design for manufacturability and identify potential cost-saving opportunities.

7. Order in Larger Quantities:

• Take Advantage of Economies of Scale: CNC machining costs are often lower per part when ordering larger quantities. If your project allows, consider ordering more parts to reduce the cost per unit.

8. Choose the Right CNC Machining Service:

• Get Multiple Quotes: Compare quotes from different CNC machining services to ensure you're getting the best price.

• Consider Experience and Expertise: Choose a CNC machining service with experience in machining parts similar to yours. They will be able to provide valuable insights and help you optimize your design for cost-effectiveness.

By following these design tips, you can significantly reduce the cost of your CNC machined parts without compromising on quality. Remember, the key is to design with manufacturability in mind and to work closely with your CNC machinist to optimize your design for cost-effectiveness.