CNC machining has revolutionized the world of small part machining, offering unprecedented precision, efficiency, and repeatability. However, manual machining still has its place in certain applications. Let’s explore the differences between CNC machining and manual machining for small parts.

CNC Machining

CNC machining involves the use of computer-controlled machines to carry out the machining operations. A CAD (Computer-Aided Design) model is created, which is then converted into instructions that the CNC machine follows. This allows for precise control over the cutting tools’ movements, resulting in highly accurate and consistent parts. br/>

One of the significant advantages of CNC machining is its ability to automate repetitive tasks. This significantly reduces the time and effort required to produce multiple identical parts. Additionally, CNC machines can execute complex machining operations that would be challenging or impossible to achieve manually.

However, CNC machining does have its limitations. It requires specialized programming and setup, making it more suitable for high-volume production runs. The initial investment in CNC machines and the necessary software can also be significant. Additionally, CNC machines may not be as flexible as manual machines when it comes to handling unconventional shapes or materials. 

Manual Machining

Manual machining, also known as conventional machining or manual milling, involves the use of manual tools and machines to carry out the machining operations. Machinists control the movements of the cutting tools by hand, relying on their skill and expertise to achieve the desired results. 

Manual machining offers a high degree of flexibility, allowing machinists to adapt to unique or complex part geometries. It also requires less upfront investment compared to CNC machining. 

However, manual machining is more time-consuming and labor-intensive. The accuracy and consistency achieved may not be on par with CNC machining, particularly for complex parts and tight tolerances. Additionally, the skill level required for manual machining is high, and finding experienced machinists can be challenging. 

Both CNC machining and manual machining have their strengths and weaknesses. The choice between the two depends on factors such as the complexity of the part, the required precision, the production volume, and the available resources.

Overview of the Machining Process

When comparing manual machining and CNC machining, it is important to note that despite their differences in operation, both methods follow the same overall machining steps. The machining process is a multi-step procedure that begins with a design and ends with a finished part. Machinists carefully analyze the design, select the appropriate materials, and determine the best machining techniques to achieve the desired outcome. Let’s explore the steps involved in the machining process. 

  1. Design Analysis: Machinists review the design to understand the part’s dimensions, tolerances, and critical features. They identify any potential challenges and determine the best approach to machining the part.
  2. Material Selection: Based on the design requirements and the intended application of the part, machinists select the most suitable material. Factors such as strength, corrosion resistance, and machinability are taken into consideration.
  3. Preparation: Machinists prepare the raw material by cutting it into the appropriate size and shape. This may involve using saws, shears, or other cutting tools.
  4. Fixturing: The raw material is securely fastened to a fixture or workholding device to ensure stability during the machining process. This is crucial to maintain accuracy and prevent any movement that could result in errors.
  5. Machining: Machinists use a variety of cutting tools, such as drills, end mills, and lathes, to shape the raw material into the desired form. This involves removing excess material and creating the necessary features and dimensions.
  6. Finishing: After the primary machining operations, machinists perform finishing techniques to achieve the desired surface quality and appearance. This may involve processes such as grinding, polishing, or coating.
  7. Quality Control: Machinists thoroughly inspect each part to ensure it meets the required specifications. This includes checking dimensions, tolerances, surface finish, and other critical parameters.
  8. Assembly and Integration: If the part is part of a larger system or assembly, machinists carefully integrate it into the final product, ensuring proper fit and functionality.
  9. Final Inspection: Before the part is considered complete, a final inspection is conducted to verify its quality and adherence to specifications. This may involve using specialized measurement tools, such as coordinate measuring machines (CMMs).
  10. Packaging and Delivery: Once the part has passed all inspections, it is carefully packaged and prepared for delivery to the customer or the next stage of the manufacturing process.


Factors to Consider When Designing Small Parts for Machining

Designing small parts for machining requires careful consideration of several factors to ensure successful manufacturing. Here are some key factors that designers should keep in mind when creating parts for machining. 

Material Selection: The choice of material should be based on the part’s intended use, as well as its machinability. Different materials have varying properties, such as hardness, strength, and thermal conductivity, which can affect the machining process.

Design for Manufacturability: Designers should aim to create parts that can be easily manufactured using the available machining techniques. Complexity should be minimized, and features that are difficult or time-consuming to machine should be avoided whenever possible.

Tolerances and Fits: Designers must specify the required tolerances and fits for each part. Machinists rely on these specifications to ensure that the parts meet the desired dimensions and can be assembled correctly.

Tool Access: Designers should consider the accessibility of cutting tools to the part’s features. Complex geometries or tight spaces may require specialized tooling or alternative machining approaches.

Surface Finish and Coating: Depending on the part’s application, designers may need to specify surface finish requirements or the need for coatings to enhance durability, corrosion resistance, or aesthetics.

Cost Efficiency: Designers should strive to create parts that can be manufactured efficiently without compromising quality. This involves considering factors such as material utilization, minimizing scrap, and optimizing machining time.

By taking these factors into account during the design phase, designers can help ensure smooth and cost-effective machining processes.

Determining the Best Method

CNC machining has revolutionized the world of small part machining by providing unmatched precision, efficiency, and repeatability. However, manual machining still holds value in certain scenarios, offering flexibility, adaptability, and cost-effectiveness. Ultimately, the choice between CNC machining and manual machining for small parts depends on the specific requirements of the project and the capabilities and resources available.  Experience exceptional precision small parts machining satisfaction at Avanti Engineering. Our highly skilled and friendly machinists are dedicated to serving you with professionalism and genuine care. Contact us today and let us exceed your expectations.