Large-part machining and parts processing are critical areas in the manufacturing industry, which involves a wide range of complex workpieces and demanding processing procedures. However, the challenges involved cnc machining large parts; large cnc machining parts are more challenging and complex than processing ordinary-sized small cnc machined parts. In this article, we will discuss the main challenges, key considerations, and weight challenges that arise during the cnc machining process of large parts and provide some strategies and methods to overcome these challenges.

Definition and scope of large parts processing

Large parts and their characteristics

Large parts typically refer to a workpiece’s size, weight, and shape. These functional parts can often create complex shapes and include components of aircraft engines, car bodies, wind turbines, and more. Their defining characteristics include their large size, weight, and complex shapes.

1. Size and weight: The size of large parts usually exceeds that of ordinary parts, which may reach the range of several meters or tens of meters, and the weight is correspondingly larger, which may reach several tons or tens of tons.

2. Complex geometry: A large part cnc machining is often challenging due to its complex shape, which includes multiple surfaces, holes, and threads.

3. High precision requirements: Large cnc machining parts often require a high level of precision to comply with their specific application field’s strict size and shape requirements despite their overall size.

4. Material diversity: Different materials, such as metals, plastics, composites, etc., can be utilized to manufacture significant components, each possessing distinct processing characteristics and specific requirements.

5. Important application areas: Large components are typically employed in top-tier industries, including aerospace, automotive manufacturing, energy, etc. These sectors demand exceptional standards for product quality, performance, and safety.

   

The scope and application of large parts processing

1. The aerospace field commonly utilizes large parts processing to fabricate various components, including aircraft fuselages, wings, engine casings, and rocket thrusters. These parts require high-precision, high-strength, and lightweight designs to meet the industry’s standards.

2. In automobile manufacturing, the processing of large parts holds significant importance. This encompasses producing various components, including automobile body structures, engine parts, and chassis. Manufacturing large parts like body shells, engine blocks, and transmission housings necessitates precision machining to ensure they meet the exacting requirements of automotive performance and safety.

3. Large-scale parts processing is employed in the energy sector to produce various equipment such as wind turbines, turbines, and nuclear power equipment. Notable examples of these large parts include wind turbine blades, tower and generator rotors, and turbine rotor and stator blade rings.

4. Within Marine engineering, producing structural elements like ships, offshore platforms, and submarine pipelines requires careful consideration. Components such as hulls, bridges, and offshore platform supports must possess qualities that resist corrosion, pressure, and high strength.

5. The heavy machinery manufacturing industry relies heavily on large parts processing to create steel, mining equipment, port machinery, and other essential products. These machines’ frames, drums, mining arms, and other components are typically oversized and require sophisticated processing technology.

Challenge 1: Material selection and processing

The influence of different materials on the processing process

Hardness and machinability:

The cutting force necessary for the machining process and manufacturing process, as well as the selection of cutting tools, are directly influenced by the hardness of the machining material. When machining high-quality parts and working with more rigid materials, it is crucial to employ cutting tools that exhibit high-quality machining parts with superior wear resistance and exert higher machining forces.

Aluminum and copper, among other soft materials, generally offer improved cutting performance, whereas steel, titanium alloy, and other more rigid materials may result in heightened tool wear and processing complexities.

Thermal conductivity and thermal expansion coefficient:

Heat transfer and accumulation in processing depend on the material’s thermal conductivity. Materials with high thermal conductivity may experience fast heat dissipation during cutting, while those with low thermal conductivity may lead to heat buildup and increased processing temperatures.

Meanwhile, the difference in the coefficient of thermal expansion will induce dimensional changes and deformations during processing, with a more pronounced effect seen in high-temperature processing.

Cutting performance and tool selection:

Variations in cutting performance and the machining process are evident across different materials. This underscores the need to choose the appropriate cutting tools, machining parts, and parameters tailored to each material. Certain materials may pose significant challenges both during cutting and machining operations, such as serrations and burrs, which may call for specialized tools and machining techniques to address important challenges.

Viscosity and brittleness of the material:

The weight limit consistency of the material will influence how the tool removes chips and applies cutting force during complex parts of the cutting operation, particularly with softer materials like aluminum alloy, plastic, and similar substances. This can result in several challenges along with tool geometry, such as clamping and chip retention.

High brittleness is a common characteristic of glass and ceramics, leading to chip breaking and surface cracking during cutting processes. To mitigate these issues, employing effective cutting strategies and designing appropriate tools and specialized equipment for production and manufacturing is crucial.

Oxidation and hardening characteristics:

During the processing phase, certain materials like stainless steel and aluminum alloy are prone to oxidation or hardening. Consequently, this can pose difficulties in cutting, compromised surface quality, reduced cutting tool longevity, and a broad range of other related problems. To mitigate these issues, it becomes imperative to implement protective measures or employ processing fluids.

How do you choose the suitable material？

Determine the specific criteria that your application necessitates. Many manufacturers assess mechanical properties such as strength, hardness, and toughness and consider environmental factors like temperature and corrosion resistance. Functional requirements and deep features, such as electrical conductivity and thermal properties, should also be considered.

Pinpoint the materials that exhibit the necessary properties to meet the application’s criteria. Factors such as mechanical properties, chemical resistance, thermal stability, electrical conductivity, and processability are considered.

Analyze the cost of materials and the availability of required complex shapes and quantities. Consider factors such as the initial material cost and processing, manufacturing, and maintenance costs in various industries that are incurred over the product’s lifespan.

Employ this tool to access material databases, industry standards, and specifications to pinpoint materials commonly available in space utilized in analogous applications. This can yield valuable knowledge regarding material properties, performance traits, key features, and potential restrictions.

Consider the environmental consequences of materials from start to finish, encompassing extraction, the manufacturing process, consumption, and disposal. Opt for materials with a low environmental impact that is recyclable or reusable.

Examine the compatibility of materials with other materials, components, substances, and environments while in operation. Consider potential interactions such as corrosion, chemical reactions, and thermal expansion.

Seek guidance from a materials engineer, specialist, or supplier to acquire valuable knowledge on optimal approaches and traditional methods for selecting materials and to effectively address any particular inquiries about the challenges above or prerequisites about your work envelope or specific application.

Anticipate possible changes or advancements in the design stage or application and select materials that adapt to evolving needs. Choose materials that are flexible, scalable, and compatible with future technologies or processes.

Solve the challenges in processing different materials.

When dealing with materials of a high degree of hardness, it is advisable to opt for cutting tools with a higher hardness level, such as cemented carbide or coated tools. This choice can significantly enhance cutting efficiency and prolong the lifespan of the cutting tool. Additionally, cutting parameters like cutting speed, feed speed, and cutting depth can be modified accordingly to fulfill the processing needs of materials with varying degrees of hardness.

Materials that are easily heat-treatable can benefit from using coolant or cutting fluid to lower the temperature and minimize the creation of heat-affected machining zones during processing. Employing internal cooling tools or high-speed cutting methods can also help decrease heat buildup in the machining zone.

Coating tools or lubricants are recommended to tackle the challenges of high-viscosity materials to mitigate friction during cutting. This reduces chip adhesion and tool wear and ensures smoother operations. Optimizing cutting parameters and tool geometry can also minimize chip formation and adhesion.

To mitigate stress concentration and crack formation while cutting brittle materials, it is advisable to employ methods like decelerating the cutting process, decreasing cutting depth, limiting cutting length, and increasing cutting speed. Furthermore, selecting appropriate cutting tools and tool geometry can reduce the likelihood of material breakage.

Utilizing processing fluids or protective gases is essential in preventing oxidation or corrosion of susceptible materials during processing. Moreover, implementing measures to regulate humidity and temperature in creating parts of the processing area can help safeguard the material from environmental influences.

Enhance cutting efficiency and processing quality by selecting suitable cnc and materials like single crystal diamond tools and cubic boron nitride tools for cutting complex materials. To achieve better results, utilize advanced technologies such as high-speed and super-hard cutting.

Challenge 2: cnc machine selection and adaptability

Requirements for large processing equipment

Large processing equipment must adhere to specific criteria when handling sizable components to carry out processing tasks efficiently and accurately. Presented below are several essential requirements for such a cnc machine:

1. Large CNC machines necessitate robust structural integrity to withstand the weight and dimensions of large machines and the sizable parts they handle. This ensures stability and prevents potential damage or accidents during the processing tasks.

2. Adequate power and capacity are crucial for large processing equipment to effectively handle the substantial workload of processing sizable parts. Sufficient power ensures smooth operation and prevents delays or inefficiencies in the processing tasks.

3. Precision and accuracy are paramount when dealing with large parts. Therefore, the equipment should possess advanced control systems and mechanisms that enable precise positioning, alignment, and movement of the components. This ensures that the processing tasks requiring specialized equipment are carried out accurately and consistently.

4. Safety features are of utmost importance in large cnc machines. The equipment should have safety measures such as emergency stop buttons, protective barriers, and sensors to detect potential hazards or malfunctions. This ensures the safety of the operators and prevents any accidents or injuries during the processing tasks.

5. Flexibility and adaptability are desirable qualities in large cnc machines. The equipment should be capable of accommodating various sizes and shapes of parts, allowing for versatility in processing different components. This enhances the equipment’s efficiency and enables it to handle a wide range of processing tasks effectively.

6. Maintenance and servicing requirements should also be considered for large cnc machining parts process equipment. The equipment should have accessible maintenance points designed for easy cleaning and upkeep. Regular maintenance ensures the longevity and optimal performance of the equipment. By adhering to these critical requirements, large cnc machined parts processing equipment can effectively handle sizable parts, ensuring efficient and accurate processing tasks.

How do you choose a machine suitable for large parts processing?

The selection of a cnc machine suitable for processing large parts involves considering various factors to meet processing requirements and enhance production efficiency.

Ascertain the equipment’s machining capability, encompassing the maximum dimensions of workpieces, weight capacity, and machining scope. Verify the machine has ample working area and travel distance to accommodate sizable components and offers adequate machining room space.

It is crucial to select a machine with exceptional rigidity and stability to guarantee sufficient support and precision while doing part cnc machining of parts and sizable components. Machines lacking in rigidity can result in vibrations and distortions during the part cnc machining process, compromising the final product’s quality.

Prioritize ensuring that the machine is equipped with a spindle of considerable power to effectively meet the cutting prerequisites for machining large parts. Moreover, the spindle’s speed range should be sufficiently extensive to adapt to the distinct demands of the machined parts of various materials and processing procedures of the machined parts.

Choose machines with high precision and repeatability to guarantee the necessary machining accuracy and surface quality for large parts. Opting for machines with low precision could result in machining mistakes and inconsistent quality.

The effect of machine adaptability on machining efficiency

High-adaptable cnc machines deliver precise machining capabilities to meet tight tolerances. This results in the machine having precise control over the machining process, ensuring that the workpiece meets strict requirements in size, weight limit shape, and surface quality.

With adaptable machines and CAD software at the helm of the production process, process transition and adjustment become a breeze, slashing switching times and minimizing production downtime. This incredible capability empowers the production line to swiftly adapt to changes in orders and demand, resulting in a remarkable production efficiency and flexibility boost.

Adaptable machines have remarkable stability and repeatability, upholding consistent accuracy and tight tolerance control throughout extended machining periods. This exceptional capability empowers the machine to fulfill the demands of high precision and stability, thereby enhancing product quality and ensuring uniformity.

Challenge 3: Machining accuracy and surface quality

Changes in machining accuracy requirements

The market’s increasing focus on product accuracy and quality drives the demand for precision in processing large parts. This shift pushes the manufacturing sector to constantly seek new ways to innovate and enhance operations to meet customer expectations for top-notch, high-precision products.

Effect of surface quality on product performance

The surface quality of parts is of immense significance as it directly influences their friction and wear properties. Smooth surfaces effectively minimize friction and wear during movement and contact. This emphasizes the importance of maintaining good surface quality, as it not only extends the service life of parts but also enhances the overall reliability and durability of the products they are used in.

A part’s sealing performance is greatly influenced by its surface quality. A smooth surface not only enhances the seal’s tightness but also acts as a barrier against the intrusion of external impurities and prevents any medium leakage.

Surface quality is not just about aesthetics; it also significantly impacts a part’s fatigue life. A rough surface may seem harmless, but it forms stress concentration points that can lead to fatigue cracks and part failures. Conversely, a smooth surface is like a superhero, reducing stress concentration and effectively prolonging the part’s fatigue life.

The significance of surface quality extends beyond aesthetics; it profoundly impacts the fatigue life of a component. Despite the seemingly harmless nature of a rough surface, it forms stress concentration points that can ultimately result in fatigue cracks and part failures. Conversely, a smooth surface is a superhero, mitigating stress concentration and effectively extending the component’s fatigue life.

In addition to impacting overall performance, surface quality directly affects the lubrication of the part. A smooth surface promotes improved adhesion and stability of the lubricating oil film, effectively reducing friction and wear on the parts. Consequently, maintaining good surface quality can enhance the lubrication effect, minimize energy loss, and ultimately enhance the efficiency and performance of the product.

How can cnc machining accuracy and surface quality be ensured?

The machining process undergoes optimization to achieve the highest machining efficiency and quality. This involves carefully considering factors like tool selection, setting cutting parameters and planning the machining machine’s travel path. Exercise caution and avoid excessive cutting speed or depth during processing to safeguard the surface of high-quality parts from potential damage.

The selection of cutting tools significantly influences the precision and quality of machining. Opting for high-quality cutting tools and carefully considering the specific processing requirements regarding tool type, size, and material is crucial to ensure a consistent and superior machining process, resulting in an exceptional surface finish.

Cooling lubricants significantly impact the machining process as they effectively lower the cutting temperature, minimize friction and wear, and enhance the overall quality of the machined surface. It is crucial to carefully choose the suitable type of cooling lubricant and adopt the appropriate application method to guarantee favorable processing outcomes and superior machining surface quality.

Conclusion

The field of large-parts processing is known for its complexity and challenges. However, manufacturers can overcome these obstacles by employing rational material selection, optimizing processing processes, and embracing continuous technological innovation. By doing so, they can achieve efficient and high-quality large parts processing. Looking ahead, as technology advances and manufacturing processes improve, the future of large-scale parts processing holds even more significant potential for development and growth.