Large Part Machining Overview

CNC Machining, custom plastic parts

Large part machining has penetrated into every aspect of our lives, such as automotive parts, construction parts, and some energy equipment parts. They are always oversized than standard parts. In manufacturing, often due to the large size, and with more difficult accuracy challenges, the processing process will be correspondingly more complex. It requires advanced machining equipment and tools, professionals and ample production experiences.

At Sungplastic, We have had the successful manufacturing experience in this field, can provide the corresponding equipment and professional knowledge, can provide a very good machining solution for you.
WordPress website
Read more about this. More professional information for you to cover.

Introduction to Large Part Machining

Large part machining is a specialized manufacturing process that involves the shaping, cutting, and finishing of oversized workpieces. It refers to the machining operations performed on components that are significantly larger in size and dimensions compared to standard-sized parts. Large part machining requires advanced machinery, specialized tools, and expertise to produce accurate and precise results.

The process of large part machining typically involves various machining techniques such as milling, turning, drilling, and grinding. It may also include additional operations like boring, tapping, and threading, depending on the specific requirements of the workpiece. Large part machining is often used in industries such as aerospace, automotive, energy, construction, and heavy machinery manufacturing.

Large part machining plays a crucial role in several aspects of modern industry. Large part machining enables the efficient production of oversized components with precision, structural integrity, customization, and cost-effectiveness. It’s able to meet the specific requirements of various industries, ensuring the reliable performance of large-scale equipment and machinery.

YouTube video

Key Considerations in Large Part Machining

Considering these key factors in large part machining helps ensure the successful production of oversized components with precision, accuracy, and efficiency. It allows manufacturers to meet the demands of various industries that rely on the fabrication of large-scale parts.

Workpiece Size and Dimensions

Large part machining requires careful consideration of the workpiece size, weight, and dimensions. The machining facility must have sufficient space and equipment capable of handling oversized components. Workpiece measurement and positioning systems should be in place to ensure accurate machining.

Machine Selection and Capabilities

Selecting the appropriate machine tools is crucial for large part machining. Machines with robust structures, high rigidity, and large working envelopes are necessary to accommodate oversized workpieces. Vertical or horizontal machining centers, large lathes, boring mills, or gantry milling machines are commonly used for large part machining.

Material Selection and Handling

Large part machining involves working with a wide range of materials, including metals, alloys, composites, and plastics. Material properties, such as hardness, heat resistance, and machinability, must be considered during selection. Proper handling and transportation methods are essential due to the weight and size of the workpieces.

Tooling Requirements

Large part machining often requires specialized tooling solutions. Cutting tools such as end mills, face mills, drills, and inserts must be selected based on the material being machined, the desired machining operations, and the workpiece dimensions. Toolholders, tool changers, and tool management systems should be capable of handling large and heavy tools.

Rigidity and Stability Considerations

Maintaining rigidity and stability during large part machining is critical to achieve dimensional accuracy and surface finish. Machines and fixtures should be robust enough to withstand cutting forces and minimize vibrations. Structural reinforcements, damping systems, and anti-vibration measures may be implemented to enhance stability.

Fixture and Workholding Solutions

Large part machining requires effective workholding solutions to securely hold the workpiece during machining operations. Customized fixtures, clamps, vises, tombstones, or hydraulic and pneumatic systems may be employed to ensure stability and accurate positioning. Fixtures should provide accessibility for tooling and allow for efficient chip evacuation.

Processes in Large Part Machining

These techniques and processes in large part machining provide a diverse range of options to shape, refine, and finish workpieces according to specific requirements. The selection of the appropriate technique depends on factors such as the part’s geometry, material, required tolerances, and desired surface finish.

Milling Operations for Large Parts

  • Face milling
    Face milling is a common milling operation used in large part machining. It involves removing material from the face of the workpiece using a milling cutter with multiple teeth. Face milling is effective for achieving flat surfaces, creating large planar features, or reducing the thickness of the workpiece.
  • Peripheral milling
    Peripheral milling, also known as slab milling, involves removing material from the periphery of the workpiece using a milling cutter. It is useful for creating straight edges, contours, or complex profiles on large parts. Peripheral milling can be performed in both horizontal and vertical milling machines.
  • Contour milling
    Contour milling is used to create curved or contoured features on large parts. It involves following a specific path on the workpiece using a milling cutter. Contour milling is suitable for producing complex shapes, such as channels, pockets, or curved surfaces.

Turning Operations for Large Parts

  • Facing and OD turning
    Facing refers to the process of creating a flat surface on the end of a workpiece, while OD (Outer Diameter) turning involves removing material from the outer surface of a cylindrical workpiece. These turning operations are commonly used in large part machining to achieve precise dimensions, smooth surfaces, and proper alignment.
  • Boring and ID turning
    Boring is the process of enlarging an existing hole or creating a cylindrical cavity within a workpiece. It is often performed using single-point cutting tools. ID (Inner Diameter) turning involves machining the inner surface of a hollow workpiece, such as cylinders or tubes. Boring and ID turning are vital for achieving accurate internal dimensions and smooth finishes in large parts.
  • Taper turning
    Taper turning is the process of creating a tapered shape on a workpiece, either externally or internally. It is commonly used in large part machining to produce conical surfaces, such as tapered shafts or bores. Taper turning can be achieved using special taper turning attachments or by adjusting the tool angle during the turning process.

Drilling and Tapping Operations

Drilling involves creating holes in the workpiece using a rotating cutting tool called a drill bit. Large part machining often requires drilling operations for various purposes, including creating holes for fasteners, alignment, or additional machining steps. Tapping is the process of creating threaded holes in the workpiece, allowing for the insertion of screws or bolts. Both drilling and tapping operations are essential in large part machining for assembly and functional requirements.

Grinding and Finishing Operations

Grinding and finishing processes are employed to achieve precise dimensions, tight tolerances, and smooth surfaces on large parts. Grinding uses an abrasive wheel to remove material and improve surface finish. It is useful for applications that demand high accuracy and fine surface quality. Finishing operations such as polishing, deburring, or surface coating may also be performed to enhance the final appearance and functionality of the large parts.

Advanced Technologies and Innovations in Large Part Machining

By leveraging these advanced technologies and innovations, manufacturers can achieve higher precision, productivity, and cost-effectiveness in large part machining while pushing the boundaries of what is possible in terms of complexity and size of machined parts.

CNC Machining and Automation

CNC (Computer Numerical Control) machining plays a vital role in large part machining, offering precise control and flexibility. Advancements in CNC technology and automation have further enhanced the efficiency and productivity of large part machining. Some key advancements include:

  • Advanced CNC controllers with improved programming capabilities and user interfaces.
  • Integration of automatic tool changers and pallet systems for uninterrupted machining.
  • Implementation of robotic systems for material handling, part loading, and unloading.
  • Utilization of sensor technology for automatic tool and workpiece measurement and tool wear detection.

Multi-axis Machining and Simultaneous Operations

Large part machining often involves complex geometries that require simultaneous machining on multiple axes. The advancements in multi-axis machining have revolutionized the manufacturing of large parts. Key innovations include:


  • Multi-axis CNC machines capable of simultaneous machining on multiple axes (e.g., 5-axis or 6-axis machines).
  • Advanced CAM software with sophisticated toolpath generation algorithms for multi-axis machining.
  • Utilization of rotary tables, tilting heads, and swivel spindles to enable complex cutting angles and orientations.
  • Integration of real-time collision detection systems to prevent tool or machine collisions during multi-axis operations.

Adaptive Machining and In-Process Measurement

Adaptive machining technologies enhance the accuracy and productivity of large part machining by dynamically adjusting machining parameters based on real-time measurements. Key advancements in this area include:

  • In-process measurement systems, such as touch probes or laser scanners, for real-time measurement of workpiece dimensions and surface profiles.
  • Integration of closed-loop feedback systems that compare in-process measurements with CAD models to automatically adjust machining parameters.
  • Adaptive control systems that can modify cutting parameters based on real-time data to optimize performance and compensate for variations or tool wear.

High-Speed Machining and Tooling Advancements

High-speed machining techniques enable faster material removal rates and improved surface finishes in large part machining. Innovations in this area include:

  • Development of high-speed spindles capable of higher rotational speeds and increased power.
  • Advancements in cutting tool materials, coatings, and geometries to withstand higher cutting speeds and reduce tool wear.
  • Advanced coolant systems for efficient chip evacuation and temperature control during high-speed machining.
  • Implementation of optimized cutting strategies, such as high-speed trochoidal or adaptive toolpath algorithms, to maximize machining efficiency.

Integration of CAD/CAM Software and Simulation Tools

CAD/CAM software and simulation tools play a crucial role in large part machining, enabling efficient programming, toolpath optimization, and simulation of machining processes. Key advancements include:


  • Improved CAD/CAM software with enhanced features for large part programming, including toolpath generation, collision detection, and optimization algorithms.
  • Integration of simulation tools that allow virtual testing and verification of machining processes, reducing setup time and minimizing errors.
  • Utilization of digital twin technology to create virtual replicas of machine tools and simulate the machining process for optimization and analysis.

Challenges and Solutions in Large Part Machining

It is difficult in the respect of machining services for large, long and heavy parts. Learn more about specific challenges and suggestions. By addressing these challenges and implementing appropriate solutions, manufacturers can enhance the efficiency, accuracy, and safety of large part machining processes.

Machine Rigidity and Stability

Large part machining presents challenges related to maintaining the rigidity and stability of the machine during the cutting process. The high cutting forces and vibrations can affect the accuracy and surface finish of the parts. To address this challenge, the following solutions can be implemented:

  • Use heavy-duty machine tools with robust structures and reinforced components to enhance stability.
  • Optimize the machine’s design to minimize vibrations, such as through advanced damping systems and vibration-dampening materials.
  • Implement effective machine maintenance and calibration routines to ensure optimal performance and rigidity.

Tool Deflection and Vibration Control

Machining large parts can lead to tool deflection, resulting in poor dimensional accuracy and surface finish. Vibration control is crucial to maintain machining stability. The following solutions can help address these challenges:

  • Select appropriate cutting tools with high rigidity and stiffness to minimize deflection.
  • Apply proper cutting parameters, including feed rates and depths of cut, to optimize tool engagement and minimize vibration.
  • Utilize advanced cutting strategies, such as trochoidal milling or high-speed machining, to minimize tool deflection and vibration.

Material Handling and Setup Considerations

Large parts often require specialized equipment and techniques for material handling and setup. Challenges in this area include the weight and size of the workpieces, as well as ensuring proper alignment and fixturing. Solutions to address these challenges include:


  • Use overhead cranes, forklifts, or other specialized lifting equipment to safely handle and position heavy workpieces.
  • Implement precision alignment systems and fixtures to ensure accurate positioning and secure clamping of the workpiece.
  • Incorporate modular and adjustable fixtures to accommodate variations in part sizes and geometries.

Surface Finish and Dimensional Accuracy

Achieving the desired surface finish and dimensional accuracy in large part machining can be challenging due to factors such as tool deflection, vibrations, and thermal effects. Solutions to improve surface finish and dimensional accuracy include:

  • Implementing high-precision tooling and machining techniques to minimize tool run-out and vibrations.
  • Utilizing advanced coolant systems to control thermal effects and maintain consistent temperatures during machining.
  • Implementing post-machining processes such as grinding, honing, or lapping to achieve the required surface finish and dimensional accuracy.

Monitoring and Control Systems

Implementing effective monitoring and control systems is crucial for large part machining to ensure process stability, detect deviations, and prevent quality issues. Solutions in this area include:

  • Utilizing sensor technology, such as vibration sensors or force sensors, to monitor cutting conditions and detect any anomalies or excessive vibrations.
  • Implementing real-time monitoring systems that provide feedback on cutting parameters, tool wear, and machine performance.
  • Integrating advanced control systems, such as adaptive control or closed-loop feedback systems, to dynamically adjust machining parameters based on real-time data.

Safety Considerations

Large part machining poses safety risks due to the size and weight of the workpieces, as well as the potential for high forces and vibrations. Safety measures and solutions include:


  • Providing proper operator training on handling large workpieces, using lifting equipment, and following safety protocols.
  • Implementing machine guarding and safety systems to protect operators from moving parts, chips, and coolant.
  • Conducting regular risk assessments and ensuring compliance with safety standards and regulations.


Stress is a critical consideration in large part machining that is often underestimated compared to smaller parts. While smaller workpieces may tolerate some degree of material stress, large parts are less forgiving. It is important to identify and address any stress-related distortions promptly to prevent adverse effects on finishing accuracy. By ensuring that stress-related issues are promptly located and resolved, manufacturers can maintain the desired dimensional accuracy and surface finish of large parts.


Tolerances become more crucial in large part machining due to the larger surface area. To ensure reliable repeatability, additional quality checks may be needed. Implementing semi-finish passes and taking measurements between them before proceeding with finishing passes can be essential for meeting strict tolerance requirements.

Temperature Considerations

Whether you’re machining small or large components, the machining process generates heat. This heat production becomes more pronounced during the machining of larger parts, necessitating proactive measures to avert potential problems. For instance, when working with large parts, allowing for intermittent cooling periods can be beneficial. While this approach extends the machining time, it significantly enhances machining precision and safeguards the structural integrity of the larger component.

Multi-Stage Machining

The risks associated with heavy-duty machining are generally heightened. If the final component fails to meet specifications, it may require alterations or even be discarded, resulting in substantial schedule disruptions and added expenses. To mitigate these risks, machining of large parts often entails multiple stages on a single machine, with inspections carried out between stages to verify dimensions. This strategy heightens the likelihood of correctly machining the component on the initial attempt and ensures consistent replication in the future, ultimately saving both time and money.

Key Industries of Large Part Machining

As a large part machining manufacturer for more than 10 years, Sungplastic has served a comprehensive array of industries, including steel, food, plastics, paper, textile, and recycling. Our experience, combined with a lineup of high-tech equipment, makes us a versatile manufacturing partner for any application.

The applications we serve include, but are not limited to:


  • Automation
  • Food processing machines
  • Oil/pipeline equipment
  • Printing equipment
  • Packaging machinery
  • Conveying bulk processing
  • Steel processing
  • Fluid power industry
  • Plastic processing machines
  • Construction equipment

Custom Services of Large Part Machining

At Sungplastic, we choose to leave our footprints in all industries, turn to solve the technological problems in manufacturing with our hard work.
We are all about quality! We work tirelessly to guarantee that the large parts include the tightest tolerances, best finishes, detailed dimensions, and excellent consistency. We have experienced technicians who will perform quality assurance verifications during the manufacturing process so that the final machined part is of the best quality and details.
We continue beyond large parts machining. Sungplastic provides a broad variety of finishing services as a full-service manufacturer, including assembly, repair, welding, heat treatment, hardness, blasting, cutting, and straightening.

Any questions and services about large parts machining can be confirmed to us.

About Sungplastic

About Sungplastic

Sungplastic is a plastic product manufacturer with rich experience in injection molding. According to the different product development requirements, we flexibly adjust the manufacturing process to achieve high quality, high efficiency and more economical.

We offer a variety of manufacturing services: Rapid Prototyping, Tool Making, Injection Molding, Product Design and Development, CNC Machining and Metal Stamping. You can choose from a variety of plastics, silicone rubber, or metal for your product. Regardless of mass production or small batch customization, Sungplastic has always been committed to providing assured, efficient and more economical one-stop processing services for your projects.

Contact us for a free quote and project review.

Get a free quote and design analysis today.

We’ll reply you within 6 working hours.
We respect your privacy.

+86 139 2927 4777 (WhatsApp, Wechat)