Checklist for Simplified CNC Part Design

Simplifying CNC part design can drastically reduce costs, improve efficiency, and minimize errors. Here’s how:

• Use Standard Materials: Choose materials like aluminum 6061 or steel 1018 for easier sourcing and machining.
• Simplify Geometries: Opt for flat surfaces, consistent radii, and avoid deep cavities or thin walls.
• Set Practical Tolerances: Reserve tight tolerances for critical areas, and use general tolerances (e.g., ±0.005") elsewhere.
• Optimize Tool Access: Ensure all features are reachable by standard tools and avoid complex setups.
• Standardize Components: Use common thread sizes, dowel pins, and mounting patterns to simplify manufacturing.

Guidelines for Simplifying CNC Part Design

Choose Standard Materials

Opt for commonly used materials like aluminum 6061 and steel 1018. These materials are easy to source, reduce waste, and work well with CNC machining processes. They also offer consistent properties and machining data, which means less time spent on testing and adjustments. When selecting materials, balance their functional requirements with how easily they can be machined.

Prioritize Simple Geometries

Stick to straightforward shapes like flat surfaces for milling, cylindrical forms for turning, and standard chamfers. These features make machining faster and more efficient. For instance, keep cavity depths no deeper than four times their width. If you're designing a pocket that's 2 inches wide, keep its depth under 8 inches.

Here are some key design tips:

• Use the same radius for internal corner fillets to reduce tool changes.
• Keep thin walls at a minimum thickness of 0.8mm to avoid deformation during machining.
• Limit hole lengths to four times their diameter to maintain accuracy.

Use Practical Tolerances

Reserve tight tolerances, like ±0.001", for critical areas such as bearing fits. For general surfaces, a tolerance of ±0.005" works well. Align all critical dimensions to a single reference point (datum) to simplify setup and ensure precision. Apply geometric tolerances only when they are absolutely necessary for assembly or functionality.

To cut costs and streamline production, stick to standard tooling and avoid custom cutters whenever possible. Additionally, limit thread lengths to three times the diameter for better efficiency.

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Tips for Improving CNC Machining Efficiency

These tips go hand-in-hand with the design checklist, focusing on how to make machining more efficient.

Simplify Machining Toolpaths

Designing parts with large-diameter cutting tools can speed up machining and eliminate the need for specialty tools. For deep cavities, using a stair-step method helps stabilize operations.

To streamline toolpaths:

• Keep wall thickness consistent and add larger corner radii to speed up machining.
• Design parallel surfaces that can be machined in one setup.
• Position features strategically to reduce unnecessary tool repositioning.

Ensure Tools Can Reach All Features

Accessible toolpaths are essential for efficient machining. Always consider the physical limitations of CNC cutting tools and their holders when designing part features. Avoid creating internal features that standard CNC machines can't reach.

Here’s a quick reference for tool clearance:

Use Standard Components

Using standard thread sizes, bearing fits, dowel pins, and mounting patterns simplifies manufacturing. For mounting holes, choose slots over precise hole placements whenever possible. This approach allows for assembly flexibility and reduces the need for tight tolerances. Standardizing features across designs also improves production planning and minimizes setup times.

"Simpler geometries and standard materials can reduce the need for complex machining operations and specialty tools."

In addition to simplifying designs, using the right tools and collaborating with experienced partners can further boost CNC machining efficiency.

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Resources to Support Better CNC Design

Creating CNC parts efficiently requires the right tools and dependable manufacturing partners. Having access to these resources can simplify the design process and help prevent expensive production errors.

Find Machine Shops with Machine Shop Directory

The Machine Shop Directory is a go-to resource for connecting designers with reliable manufacturing partners. With over 200 highly rated machine shops listed, you can easily find the right partner for your CNC projects. The directory allows you to filter by material capabilities, machining processes, and certifications, ensuring you select the best match for your needs.

After choosing a trusted manufacturing partner, the next step is to use advanced design tools to ensure your parts are ready for production.

Use CAD and Simulation Tools

Top-tier software like Autodesk Inventor, SolidWorks, and Fusion 360 can improve your design process. These tools offer features such as DFM (Design for Manufacturing) analysis, material selection guidance, and machining simulations, all of which make it easier to validate your designs. They also help ensure your designs follow best practices, like using standard materials and maintaining realistic tolerances.

"Studies have shown that using DFM tools and collaborating with manufacturers early in the design process can lead to significant reductions in design-to-manufacture time and cost. For example, a study by Fictiv found that using DFM tools can reduce manufacturing costs by up to 50%."

Conclusion

Using the right tools, resources, and partnerships makes adopting streamlined design principles much easier. Industry case studies show that these principles can cut production time by up to 30% and lower manufacturing costs by 25%.

The key to effective CNC design lies in balancing functionality with manufacturability. Sticking to standard materials, straightforward geometries, and practical tolerances helps reduce setup times, limit errors, and avoid expensive processes. A highly effective strategy is designing parts for single-setup machining on 3-axis CNC machines. Pairing this with general-purpose tooling can simplify production and reduce costs. To maintain part integrity, prioritize rigidity by avoiding thin walls and overly intricate contours.

Working with experienced manufacturers is essential for making these design improvements a reality. The Machine Shop Directory, featuring over 200 verified machine shops, is a great tool for finding partners who can help implement these practices.

CNC part design is not a one-and-done task - it’s a continuous process. Regularly reviewing and refining your designs, while incorporating feedback from manufacturing partners, ensures ongoing improvements in efficiency and cost. By collaborating closely with manufacturers and using DFM tools, you can achieve better results over time.

FAQs

How to make machined parts cheaper?

Looking to cut costs on CNC machined parts? Here are some practical strategies to help you achieve that:

Production Strategy Tips

• Group similar parts for batch production to save setup time.
• Break down complex designs into simpler assemblies.
• Use standardized workholding solutions.
• Run digital twin simulations to spot cost-saving opportunities.

Reducing Non-Machining Costs

• Design parts that allow for automated deburring.
• Minimize the need for secondary operations.
• Factor in workholding during the initial design phase.
• Add self-fixturing features to improve quality control.

Smart Design Choices

• Stick to standard stock sizes to reduce material waste.
• Optimize designs for longer tool life and fewer tool changes.
• Plan for automated inspections early on.
• Design parts for automated loading and unloading when possible.

Some specific design elements can directly impact costs. Here's a quick breakdown:

Advanced Cost-Saving Techniques

• Use predictive strategies to monitor tool wear.
• Design for "lights-out" manufacturing (fully automated production).
• Include features that simplify in-process measurements.
• Plan for automated tool condition monitoring.

"Industry experts emphasize the importance of simplified CNC part design for reducing costs and improving manufacturing efficiency. Trends such as the use of standard materials and minimizing machine setups are becoming increasingly popular in the industry".

Case studies reveal that applying these principles can slash manufacturing costs by up to 50%. For instance, redesigning a part to allow single-setup machining instead of multiple setups can drastically cut production time and expenses.