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6 Mistakes to Avoid When Designing for CNC Machining

Save time and money by avoiding some of the most common mistakes.

Your designs breathe life into concepts.


With CNC machining, your designs can transform into tangible parts, combining precision and efficiency. Good designs can streamline the production process, while mistakes can lead to unnecessary costs, delays, or even part rejection. In this article, we'll explore common mistakes to avoid when designing for CNC machining to ensure you get it right.

 

Don't Underestimate Material Selection

 

Material selection is not just a checkbox in your design process. It's a vital decision that impacts every stage of your part's life—from machining to its functionality in the end-use environment. Picking the wrong material can lead to poor surface finishes, excessive tool wear, or even complete tool breakage.


Each material has its properties, like hardness, elasticity, and thermal stability. These factors affect how it interacts with the cutting tools and ultimately determine the part's performance. Therefore, when selecting your material, carefully consider the attributes needed for your part's intended application and how these align with the material's properties.


These two articles will help:


Our experienced engineers can help you find the perfect material to balance cost with performance. Use the MakerVerse platform to start your project.

 

Never Ignore Design for Manufacturability (DfM)


Design for Manufacturability (DfM) is a design principle that simplifies manufacturing. It involves considering the capabilities and limitations of the manufacturing process during the design stage. When DfM principles are neglected, you may find yourself wrestling with an expensive design to produce, time-consuming to machine, or in a worst-case scenario, unmanufacturable.


Of course, understanding DfM is a lot easier said than done. To get you started, these articles offer a few tips.



By incorporating DfM into your design process, you can avoid costly and time-consuming revisions while optimizing manufacturing efficiency.

 

Avoid Unnecessary Geometric Complexity

When producing complex parts, just because you can doesn't mean you should.


CNC machining is incredibly versatile, producing a wide range of complex geometries. However, complexity comes with a price. Overly complex designs often increase production times as the machine takes longer to navigate intricate paths. This, in turn, can inflate the overall cost of your project.


Furthermore, complex parts may require additional setups or specialized tooling. These additional requirements could further increase your costs and extend production times. Therefore, while leveraging the versatility of CNC machining, always aim to keep your designs as simple as possible.



A more straightforward design can lead to a smoother machining process, quicker production times, and lower costs.

 

Don't Neglect Wall Thickness

 

The wall thickness of your part plays a critical role in determining its final quality. Too thin, and your part may suffer from structural weaknesses. In the worst case, it can deform or break during machining. On the other hand, excessively thick walls can lead to longer machining times and unnecessary material costs.

 

Each material has a recommended wall thickness that balances strength and machinability. Adhering to these guidelines ensures your part has the necessary structural integrity without wasting material or time. Remember to prioritize structural stability over weight reduction even when pushing for a lightweight design.

 

Remember to Optimize for Tool Access

 

Designing for CNC machining isn't just about the part—it's also about how your cutting tools interact with that part. If your cutting tool can't reach a feature due to a design oversight, you may need to adjust the part orientation or even change the tool, which can disrupt the workflow and lengthen production time.

 

When designing your part, envision how the tools will traverse it. Make sure that all features are accessible and that the tools can achieve the necessary angles for machining. By taking tool access into account during your design phase, you can prevent machining challenges and ensure a more efficient production process.


Here's an example of what to do: When it comes to CNC drilling, the manufacturer needs space or access from the top of the closest wall or the clearance between the tool holder and the closest wall. That means to have a 12 mm drill center to the wall or drilled depth, plus wall under 8 times the hole diameter.

Keep Assembly Simple

 

If your part is a piece of a larger assembly, consider the assembly process during your design phase. Overcomplicating the assembly design can lead to longer production times and an increased chance of assembly errors. This complexity can translate into higher costs and lower production efficiency.


Instead, aim for simplicity in assembly design. A well-designed part should fit seamlessly within its assembly and simplify, not complicate the assembly process. Remember that every unnecessary feature or overly tight tolerance can add unnecessary complexity to the assembly process.


Launch Your Next CNC Machining Project with MakerVerse


Designing for CNC machining is an exercise in balance—balancing form and function, complexity and manufacturability, innovation and practicality. By avoiding these common mistakes in your design process, you can help streamline production, save costs, and reduce lead times.


If you need any help at all, we're here to help. Our experts can you know if there are any design issues and work with you to ensure you get a high-quality part.


 

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