A Basic Guide to Large CNC Machining

Jack Lie CNC machining expert

Specialize in CNC Milling, CNC Turning, 3D Printing, Urethane Casting, and Sheet Metal Fabrication Services.

Micromachining requires a high level of skill and expertise, not excepting CNC machining of large components that need specialized equipment large enough to process large-scale productions. However, large CNC machining may not be a straightforward process. There are lots of things to consider to optimize the whole manufacturing process and get the best results. In this article, we’ll have an overview of large CNC machining, also referred to as large diameter machining or heavy duty machining, and you’ll know its definition, application, and considerations better.

What Is Large Part CNC Machining?

Large part CNC (computer numerical control) machining is a manufacturing process that involves using computer-controlled equipment to cut, shape, or form large pieces of materials into precise and complex shapes. This process is typically used to produce large metal parts and components that are too large or too complex to be manufactured using traditional machining techniques.

CNC machining involves the use of a CNC machine, which is a specialized type of computer-controlled machine tool that is programmed to follow a set of instructions to move a cutting tool or other tooling across the surface of a workpiece. The CNC machine is programmed using a computer software that generates a set of instructions, called a CNC program, which tells the machine how to move and what cuts to make.

Large part CNC machining is typically used to produce parts that are too large or too complex to be manufactured using traditional machining techniques. It is a highly accurate and precise process that allows manufacturers to produce large parts with tight tolerances and excellent surface finishes.

Applications for Large Part CNC Machining?

Large part CNC machining is often used in the manufacturing of structural components for a variety of industries including aerospace, military, energy, and transportation. Some examples of large parts that are typically machined using CNC technology include:

  • Aerospace: aircraft fuselages, wing components, and landing gear
  • Military: armored vehicles, naval vessels, and missiles
  • Energy: wind turbine blades, oil rig components, and hydroelectric power plant parts
  • Transportation: heavy machinery, train components, and large vehicles such as buses and trucks
  • Automotive: the automotive industry utilizes large CNC machining to make shafts, engines, and other vehicle components
  • Mining: large diameter machining is ideal for creating parts used in strong and large equipment in the mining industry, such as ranging arms, gearboxes, and gear racks.
  • Oil and Gas: heavy duty CNC machining plays an important role in the drilling occasions to manufacture oversized components of their equipment, including mud/fracking pumps, gearboxes, and rods.
  • Other common applications for large part CNC machining include the production of molds for plastic injection molding, dies for metal stamping, and fixtures for various manufacturing processes.

Considerations for Large Part CNC Machining

Considerations for Large Part CNC Machining

There are several factors that should be considered when planning a large part CNC machining project:


The conditions in the initial stage of CNC machining process are crucial factors in making high-quality large parts, some of which are listed below:

  • Work Area
    CNC machinery used for large parts machining needs a larger work zone and higher reach that allows for efficient machining of these parts.
  • Temperature
    The temperature should be taken into consideration during CNC machining large parts processes. In general, this process will generate heat. A typical case is the heat from friction. A temperature change will cause a change in workpiece dimensions.
  • Stress
    There is a high probability of incurring stress in the large CNC machining process. The stress may lead to workpiece distortion in the manufacturing process.


The preparation of large part machining is concerned with the pieces of equipment required, and the space for placing heavy and large equipment and parts. You can prepare for this process by the following:

  • Weight supports
    A larger part comes with a large weight. It’s also a significant factor to note and weight supports are recommended use.
  • Collision elimination
    The probability of collision grows with an increase in part size when machining large diameter parts. Optimization of the CAD file is a practical manner to solve this problem. The first step is to check the relationship between the enclosure’s interior and the design.
  • Using CNC Routers
    You’re supposed to incorporate a CNC router to process large parts. A CNC router with big work envelopes is suitable for this process.
  • Preparing Loading Equipment
    Loading equipment may be not a necessary tool required for the large part machining process, but it can well fit in situations where the heavy part is difficult to carry.

Machining Process

After talking about the factors to consider at the beginning of machining, it’s time to discuss other important things during the large part manufacturing process.

  • Material
    The material being machined will have a big impact on the machining process. Some materials are easier to machine than others, and the choice of material will also affect the type of tooling and cutting techniques that can be used.
  • Size and complexity of the part
    Large parts can present challenges in terms of handling and machining due to their size and weight. It is important to carefully plan the machining process to ensure that the part can be moved and held in place accurately during the machining process.
  • Tolerances
    The required tolerances of the finished part will also have an impact on the machining process. Tight tolerances will require more precise machining techniques and may also require additional processing steps such as heat treatment or grinding.
  • Surface finish
    The required surface finish of the part will also need to be considered. Some machining processes are better suited to producing high-quality surface finishes than others.
  • Tooling and equipment
    The choice of tooling and equipment will be determined by the material, size, and complexity of the part, as well as the required tolerances and surface finish. It is important to carefully select the right tooling and equipment to ensure that the machining process is efficient and produces high-quality parts. Common tools available to enhance the operation further include planers, shapers, power saws, grinding machines, layout, and moving equipment.
  • Cost
    The cost of the machining process will depend on a variety of factors including the size and complexity of the part, the material being machined, the required tolerances and surface finish, and the tooling and equipment needed. It is important to carefully plan the machining process to minimize costs and ensure that the project is completed within budget.

Turn On Runsom Precision for Your Large CNC Machining Projects

Large CNC Machining Projects

Component manufacturing is an arduous process from precision and stress to tooling and tolerances. All of these challenges are magnified when parts are heavy and large. It’s a daunting task for some shops that just move the material around. But at Runsom Precision, we’re proud of the efficiency and capacity to fabricate heavy-duty components to meet our customers’ requirements and needs. That means we have the confidence and capability to handle projects that may be too complex or difficult for other machine shops. Get started with your CNC machining large part quote today!

Learn more about our large CNC machining capability.

Other Articles You May be Interested in: