What Is CNC Machining & Why Is It Important?

Computer numerical control (CNC) machining is a cornerstone of modern manufacturing. You may have heard of the process, but you’re not sure of exactly what it entails and how it can benefit your business. This guide from Jaeckels Industrial will explain what CNC machining is, explore its different types, and highlight why it is important in modern production. By the end, you will have a clear picture of how this technology drives innovation and efficiency across various sectors, including yours.

What Is CNC Machining?

CNC machining is a manufacturing process that uses computer-controlled machines to precisely cut, shape, and finish materials into custom parts and products. This technology has enabled manufacturers to produce complex parts with high repeatability.

How Does the CNC Machining Process Work?

The CNC machining process follows a structured sequence of steps to turn a digital design into a physical object. It all begins with creating a digital model of the desired part.

1. Designing the Part With CAD

The first step is the creation of a 2D or 3D model using computer-aided design (CAD) software. Engineers and designers use programs like AutoCAD, SolidWorks, or Fusion 360 to create a detailed digital blueprint. This file specifies the part’s exact geometry, dimensions, and material properties.

2. Converting the File With CAM

Once the CAD model is complete, it needs to be translated into a language the CNC machine can understand. This is where computer-aided manufacturing (CAM) software comes in. The CAM program generates the toolpaths and converts the design into a set of machine-readable instructions, known as G-code.

G-code directs the machine’s movements, controlling factors like tool speed, feed rate, and the precise coordinates for cutting. Essentially, this code is the operational script that the machine will follow to create the part.

3. Setting Up the CNC Machine

With the G-code generated, the next step is to prepare the CNC machine. An operator secures a block of raw material, known as a workpiece, onto the machine’s worktable. They also install the necessary cutting tools, such as drills or end mills, into the machine’s spindle.

The operator then loads the G-code program into the CNC machine’s computer. Lastly, they perform a series of checks to confirm the machine is properly calibrated and the workpiece is correctly positioned.

4. Executing the Machining Operation

After the operator completes setup, they initiate the program. The CNC machine takes over, executing the G-code instructions autonomously. The machine’s cutting tools move along the programmed paths, removing material from the workpiece to shape it into the final part. As this happens, the machine shoots out coolant to prevent the high-speed moving parts and friction from overheating and causing a fire or melting the workpiece.

This process requires minimal (and usually zero) operator intervention once it begins.

Common Types of CNC Machining

CNC technology applies to a wide range of subtractive manufacturing processes. While there are many types of CNC machines, a few are particularly common in modern production environments. Each type is suited for creating different kinds of parts and features.

CNC Milling

CNC milling is one of the most versatile machining processes. It uses rotating multipoint cutting tools to remove material from the workpiece. The workpiece is typically held stationary on a movable table, which positions it relative to the rotating tool.

Milling machines can create a wide variety of shapes, slots, holes, and flat surfaces. Advanced multi-axis milling machines, such as 5-axis machines, can produce highly complex geometries by moving both the tool and the workpiece simultaneously on multiple axes.

CNC Turning

CNC turning involves holding and rotating a workpiece in a chuck while a single-point cutting tool is fed into it. This process is performed on a CNC lathe. As the workpiece spins, the tool removes material to create cylindrical parts with internal and external features, such as tapers, grooves, and threads. Turning is ideal for producing rotational parts like shafts, rings, and cones.

CNC Drilling

CNC drilling is a process used to create holes in a workpiece. The machine uses rotating drill bits to bore holes of specific diameters and depths. This process is often integrated with milling or turning operations on a single CNC machine.

Drilling is a fundamental machining operation required for many parts that need to be assembled with screws, bolts, or other fasteners.

CNC Grinding

CNC grinding uses a rotating abrasive wheel to achieve a very fine finish and precise dimensions on a workpiece. The grinder removes small amounts of material, resulting in a smooth surface and extremely tight tolerances. This process is often used as a finishing step after other machining operations.

The Importance of CNC Machining

The positive impact of CNC machining is apparent across nearly every industry that relies on the production of physical components.

Unmatched Precision and Consistency

CNC machines can produce parts with tolerances as tight as a few micrometers. And because the process is automated, there’s less room for the human error that plagues manual machining. This results in high repeatability, where every part exits the process virtually identical to the last. This consistency is essential for industries like aerospace and medicine, where even minor deviations can have serious, life-threatening consequences.

Increased Production Efficiency

Once a CNC program is created and verified, a machine can run continuously with minimal supervision. This automation allows for 24/7 production, leading to faster turnaround times and higher output. Additionally, a single operator can often oversee multiple machines, which optimizes labor and reduces operational costs.

Complex Geometry and Design Freedom

CNC machining enables the creation of intricate shapes and complex geometries that would be difficult or impossible to produce with manual techniques. For example, multi-axis CNC machines can create parts with curved surfaces and internal features with a high degree of accuracy. This capability gives engineers greater design freedom to develop innovative and optimized components.

Material Versatility

CNC machines can work with a vast range of materials, from metals like aluminum, steel, and titanium to plastics like ABS and polycarbonate. This versatility makes CNC machining suitable for a wide array of applications. Manufacturers can select the best material for a specific part’s requirements, whether it’s strength, weight, or heat resistance.

Partner With a CNC Expert Today

Now that you know what CNC machining is and why it’s important in today’s manufacturing landscape, the next step is applying these benefits to your business. If you have a part you need to manufacture precisely and at scale, then working with a reputable CNC manufacturer can make that happen. At Jaeckels Industrial, we help businesses thrive with everything from palletizing robots to custom machining services. Reach out to discuss your needs today.