Large CNC Machining: Everything You Need to Know

large machining

Large CNC machining is also known as large diameter machining, it is a subdivision of the CNC machining process and is aimed at manufacturing mechanical parts having large diameters. Large CNC machining process also offers the same attributes i.e., excellent mechanical efficiency, high precision, excellent processing accuracy, and high tolerances as offered by the CNC machining process.

But the practical application of large CNC machining is not that simple as it is in a simple CNC process. Many factors must be considered before starting the process and will be discussed ahead in this article.

In this article, you will be comprehensively introduced to large CNC machining, when you should use it, and what is necessary for you to know about it. The applications of large diameter machining, design consideration of large CNC parts, and technical setup will also be discussed.

Different Situations in a Large CNC Machining Process

The large part CNC machining process is a subtractive machining process that is directed towards manufacturing different products with large diameters. As we do in CNC machining, we create a drawing of the part termed as CAD design, then generate a CAM code, and after setting the machine up, it is ready to go. But large part CNC machining process is not easily manageable and simple. Along the process, there can be many different situations that can play a huge role in the process. So, to learn how to deal with these situations keep on reading.

How Large CNC Machining is Used in Different Industries

There are a few numbers of industries that use large CNC machining services because of the large diameter products. These require large diameter machining in the manufacturing of their different products, tools, or machines. The industries using these services are given as follows  

  • Aviation Industry

           The aviation industry needs parts with large diameters and this purpose is served by Large CNC machining. Because it provides high precision and excellent processing accuracy. The aviation industry cannot use such a method that is not proficient and reliable because the lives of humans rely on this. Therefore, large CNC machining is a better choice for aviation to manufacturing new product designs, replacements, and up-gradation of the parts.

  • Power Generation Industry

            To fulfill the needs of the power, it is required to manufacture large, hefty, and sturdy machines like turbines, engines, generators, transformers, etc. that can generate electricity for masses. To manufacture these giant machine’s complex parts, a technology like large diameter machining suits exemplary. Because manufacturing these power generating equipment demand excellent processing efficiency, high precision parts, and outstanding accuracy. THE large CNC machining process does this task of manufacturing these heavy and big machines superbly.

  • Oil and Gas Industry

             To get oil and gas, it needs drilling thousands of feet deep and it requires giant machines. Large CNC machining services find ideal in manufacturing these drilling machines. These large diameter machines include connecting rods, pumps, bell nipples, etc.

  • Automotive Industry

            The automotive industry uses small-scale CNC machining services for manufacturing their prototype samples. But when it comes to mass production, they tend to choose large CNC machining for various absolute reasons and benefits that this technology offers. The automotive industry uses these services for the manufacturing of various parts of the engine, shaft, and other vehicle components.

Important Considerations Before Starting Large CNC Machining Process

Before starting the CNC machining process for manufacturing large diameter and complex parts, it is necessary to consider a few important factors. These factors include design requirements, machine setup, and proper tools choice. As we discussed above the large CNC machining process is not an easy and simple subtractive manufacturing process. So, consider the following salient things before starting the process

1: Design Consideration

While making a product’s design, it is important to consider the following conditions that can influence the design and can affect the product’s quality.

  • Reduce Complexity

            Before starting this intricate CNC process, the complexity in making the design of the part must be considered. Then it comes to the point wheatear it can be manufactured using a large CNC machining process or not.

  • Minimize the Temperature

            Applying CNC machining technology to manufacture large parts will generate an excessive amount of heat. If a proper cooing method is not being applied at an appropriate time then it may result in workpiece deformation. Even in a simple CNC machining process, the friction between different tools and workpieces may cause deformation. In the case of large diameter machining, the effect of temperature must take into consideration according to part’s design prospects.

  • Manage Internal Stress and Distortion

            Dealing with the large diameter parts, there is a possibility that the process may introduce stress into the workpiece. Once stress is introduced then it can cause distortion that will ultimately disturb the final product and it must be taken care of.

These above-mentioned points are worth considering before starting the process otherwise things may get out of control and it can lead to a waste of time and money.

2: Ensuring Necessary Preparations

Before starting the manufacturing process, it is mandatory to strategize the whole CNC process and ensuring the availability of the necessary equipment required to accomplish the process. Some important pre-preparations are discussed as follows

  • Eradicating the Possibility of Equipment Collisions

            During the execution of the process, it must be taken care of that large-sized parts are being manufactured and there is the possibility of equipment collisions due to worker’s carelessness or mismanagement. So, it is advisable to eradicate the chances of such collisions. One piece of advice for reducing this collision is by making CAD file optimization further better. First, check the relationship between the design and the enclosure’s interior. If there seems a minor possibility of the collision then optimize the CAD file more carefully.

  • Using a CNC Router

            As we are dealing with heavy CNC parts so, to ensure better processing accuracy, it is highly recommended to make use of a CNC router. Because integrating a CNC router during the execution of a large CNC machining process will result in excellent machining accuracy.

  • Supporting the Part’s Heavy Weight

            Since we will be applying this subtractive technology on large workpieces which means we have to deal with larger weights. Therefore, we must make necessary arrangements so that, we can easily move the heavy parts without any disturbance and delay in the process.

3: Machine Setup

Because large part CNC machining process is not easy going. Therefore, below we discuss some important points that will help in making the complex process as smooth as possible.

  • Opening the Machine Up

            This complicated process will generate an excessive amount of heat. So, to deal with this, if we open the machine up then we can easily manage the cooling period. It means managing the cooling during the machining process will help to reduce the temperature and workpiece deformation can be minimized.

  • Strategize the Whole Machining Process

            Because of the higher degree of complexity involved in the process, it is recommended to strategize the whole machining process. The whole process can be divided into small steps. So, by completing each step, it will quite easy to execute the process easy and complete it efficiently.

  • Slid and Spin Big Parts

            Machining large parts are not easy and moving them is not that simple. Well, when we have to move a rectangular-shaped workpiece then we use an impromptu rig. But when it is required to move a round-shaped part then we can spin them to subtract each side as required. Using an impromptu rig will allow sliding a large and heavy rectangular part.

4: Appropriate Tools Selection

Appropriate tool selection is very important while executing a large part CNC machining process. The tools used in this process are a little bit different from the ones we use in a regular CNC process. Therefore, it is required to modify the tools according to the larger workpieces. So, we will use standard large diameter machining tools such as large turnings, large CNC mills, large boring machines, etc. Some common tools used are discussed below

  • Layout and Moving Equipment

            As we discussed above in the pre-preparation that we must subsume the necessary loading tools. These loading tools include forklifts, hoists, overhead cranes, and rigging hardware. Again, which size is appropriate will depend on the size of the workpiece being subtracted.

  • Grinding Machine

            The grinding machines used in this process must have a comparatively larger surface area than we use normally. Because the parts have been bigger. A machine that is used to remove small metal pieces by establishing a contact between a removing surface and a high-speed abrasive wheel is termed a grinding machine. A grinder is considered a mandatory tool in machining.

  • Shapers

            When it is required to flat a surface, make grooves, and angular surfaces then we use shaper tools. Shapers are also important tools in machining. A cutting tool is used in shapers that escalate for the cutting process. It cuts with a forward stroke while the return stroke brings the workpiece towards the shaper.

The tools that are discussed above, other than these there are more tools such as planers, power saws, etc. The selection of these tools will also be the same as we did for the above tools.


Well, the large CNC machining process is not simple as compared to the normal CNC process. Though, it requires a lot of team effort to execute the successful matching process and produce excellent results. After reading the article, we hope you will get to know a lot about large diameter machining and will be helpful for you.

If you need large diameter parts to be manufactured with excellent accuracy and high precision then just CONTACT US!

Cora Feng
Cora Feng

Project Manager working on CNC Machining since 2010

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