The CNC Machining Process
The CNC Machining Process

The CNC Machining Process

Aerospace, automotive, defense, electronics, medical equipment, name them. These and numerous other industries rely on CNC machining services. Finding a high-tech manufacturer that doesn’t is an uphill task. 

With good reason. 

What Is CNC Machining?

CNC machining, or Computer Numerical Control, is among the many reductive processes that shape a workpiece or raw material to meet precise demands.

CNC machining meets a similar function as traditional machining; metal cutting, milling, boring, drilling, and other metal manipulation and removal functions. 

However, instead of these processes being done manually, CNC machining uses computer numerical controls rather than being manually controlled by a machinist. The result? Consistent precision.  

When you are looking to replicate a particular design for duplicate items in large or small-scale production, CNC machining is it.

CNC Machining Process

CNC machining features complex commands and offers greater control. This allows CNC machining to customize complex instructions from CAM or CAD designs. 

While different CNC machining equipment has varying capabilities, the machining processes typically follow four steps, as discussed below.

1. Prepare a CAD Model

The CNC machining process begins with a product design. Computer-Aided Design (CAD) software is used to build two-dimensional (2D) or three-dimensional (3D) models. 

These have different design components, including geometrics and technical specifications and dimensions. In essence, CAD software compensates for limitations in the machining processes.

For example, most CNC machine tooling is cylindrical, which means CNC machining processes are limited to curved corner sections. Other features of a design similarly add more restrictions. CAD models should therefore be properly designed to show crucial elements such as threads, construction lines, tolerance, and other parameters. 

2. Converting CAD Files to Usable CNC Instructions

After design completion, these designs need to be put in a language whose directions CNC can understand. The CAD files are run through computer-aided manufacturing software (CAM) to do this. 

These programs create a programming code or CNC machines to direct tools during the manufacturing process. The software also gets information regarding the part geometry to ensure the final output features the correct orientation and dimension. 

These instructions are set in STEP or IGES files and include languages like M-code and G-code. These code specific areas of machine tools’ functionality. For example, G-code focuses on actual tool operations like speed, the direction of movement, and the distance they cover. While the G-code can direct a machine to take on several functions, it wouldn’t know when to stop, add coolant, or change tools. This is where the M-code comes in. 

M-code covers functions like telling the machines when to begin or cease operations. 

3. Preparing the CNC Machine

While CNC machining isn’t as labor-intensive as manual machining, it still does require human manipulation. Some crucial roles operators need to handle include:

  • Loading CNC program files
  • Placing workpieces in the machine spindles or vices for manipulation
  • Attaching specified machining tools like drilling bits
  • Supervising and inspecting the workspace, workpieces, and machines

4. Machine Operation Execution

After designs are made, and instructions are given, the CNC machines execute directions on a workpiece. The program can complete all the steps from start to finish without additional operator input. 

Once the machines complete the instructions, they can continue to the finishing and packaging processes. 

The term machining operations has come up severally. What do we mean by this?

CNC Drilling

Drilling uses multi-point drill bits to produce cylindrical holes in a workpiece. To do this, machining equipment inserts a spinning drilling bit perpendicularly into a workpiece until a hole of a predetermined length is acquired. 

You can also use more complex equipment for angular holes. Drilling tools can also be used for counterboring, countersinking, reaming, and tapping. 

CNC Milling

Milling entails employing rotating multi-point cutting tools to remove material from a workpiece. With CNC milling, the CNC machine will typically feed the workpiece to the cutting tool in the same direction as the cutting tool’s rotation. In manual milling, machines feed the workpiece in the opposite direction to the cutting tool’s rotation. 

Some operational capabilities of milling include:

  • Face milling: cutting shallow, flat surfaces and flat-bottomed cavities into a workspace
  • Peripheral milling: cutting deep holes like threads and slots into the workpiece

CNC Turning

Turning pieces maneuver the workpiece instead of the cutting tool. These processes include grooving, facing, and boring. 

With CNC turning, excess material is cut off the workpiece using single-point cutting tools applied precisely to a rotating workpiece. In turn, this turning creates cylindrical bits with a specified diameter. 

Turning will create linear features inside and on the exterior parts edge of the parts. These features include:

  • Tapers
  • Threads
  • Slots

Reasons To Use CNC Machining

So why CNC machining and not manual manipulation of workpieces? 

CNC machining has a wide application in manufacturing due to the value it provides. Some of the key benefits include the following:

Accuracy and Precision

CNC machining offers high levels of accuracy, allowing manufacturers to make replicas of the intended design. Besides that, it gives you high precision and tolerance, with lets manufacturers produce different batches of a product while maintaining accuracy.

In addition, the entire process is highly automated, which minimizes errors. This is a huge advantage considering how costly mistakes in manufacturing can be for a business. 

Fast and Efficient

Each CNC machining process begins with CAD designing, so prototyping is much faster. Similarly, the software flags any or prevents most potential design flaws or potential risks that could crop up with different materials. 

When prototyping and testing processes are shortened, products move from design to production much faster. In manufacturing, this level of efficiency significantly boosts production and sales. 

Better Capabilities

Many CNC machining tools can carry many tools for varying purposes. They also have sophisticated software that allows them to work on different, complex products and workpieces. 

This provides for enhanced capabilities of different textures, shapes, and sizes. In the highly competitive marketplace businesses exist in today, this quality is a must-have. 

Ready To Start Your Project?

We can tell you one thing for free: your competitors are using CNC machining. So should you. 

However, you need a machining partner that understands your business and supports your goals. That’s precisely what we aim to do at Cast Technologies. With us, you get improved quality control, enviable response times, cost-effectiveness, and top-notch quality. 

Contact us for your next project, and let us help you get where you need to be.