What Is CNC Routing & How Does It Work?

What Is CNC Routing & How Does It Work

Have you ever wondered how intricate designs are carved into soft materials like wood, plastic or metals with such precision? Well, enter CNC routing.

With its ability to create complex shapes with ease, CNC routing has become an indispensable tool in industries ranging from furniture manufacturing to architectural design. Discover the inner workings of this cutting-edge technology as we peel back the layers and reveal how it transforms raw materials into stunning masterpieces.

Understanding CNC Routers

What is a CNC router? It is a computer-controlled machine used for cutting, shaping, and engraving various materials such as wood, metal, plastic, and composites with unparalleled precision. What sets CNC routers apart from traditional routers is their ability to follow precise design instructions, making them ideal for intricate and repetitive tasks. They operate based on numerical codes, or G-codes, that guide the router’s movements.

In a nutshell: A CNC router is a computer-controlled cutting machine that precisely follows a computer program and design instructions to create intricate and accurate cuts and engravings.

Types of CNC routers

CNC routers come in various types, each designed to cater to specific needs and applications:

  1. 3-Axis CNC Router: This type moves in three directions (X, Y, and Z) and is suitable for flat surfaces and simple three-dimensional work.
  2. 4-Axis CNC Router: Adding a rotational axis to the 3-axis system, the 4-axis router is capable of more complex 3D work and can create cylindrical or tapered shapes.
  3. 5-Axis CNC Router: The pinnacle of CNC routing, the 5-axis router adds two additional rotary axes, allowing for intricate and multidimensional cuts on complex shapes and objects.

Components of a CNC router

The components of a CNC router play a crucial role in its functionality and efficiency. One of the key components of handheld router is the spindle, which is responsible for cutting and shaping materials. Modern CNC machines and routers often use high-speed spindles that can reach incredible rotational speeds, allowing for precise and intricate designs.

Another vital component is the gantry system, which consists of structural supports and linear motion guides. This system provides rigidity and stability to the machine, ensuring accurate movements during cutting operations. The gantry drive system also includes servo motors or stepper motors that drive the axis movements, enabling smooth and controlled motion.

Additionally, a CNC mill or router typically includes a control panel or interface where users can input their desired design parameters. This control panel allows operators to adjust settings such as feed rates, spindle speed, tool changes, and more. Some advanced machines even feature touchscreen interfaces with intuitive navigation menus for user-friendly operation.

How CNC Routing Works

The CNC routing process involves several basic form essential steps:

Design and CAD/CAM Software

If your project demands 2D precision, CAD software is used to create two-dimensional drawings. In this phase:

  1. Sketching and Drafting: Begin by sketching your design concept. CAD software allows for precise drafting, enabling you to create clean and accurate 2D drawings.
  2. Geometric Modeling: Utilise tools for geometric modelling to create shapes, lines, and dimensions with precision. These 2D designs serve as the foundation for your CNC routing project.
  3. Editing and Refinement: CAD software enables easy editing and refinement, allowing you to make adjustments to the design as needed to meet client specifications.

Once the design is complete, it’s time to transform it into a digital format that the CNC machine and router can understand and execute. This is where Computer-Aided Manufacturing (CAM) software comes into play:

  1. Toolpath Generation: CAM software interprets the 2D or 3D design and generates toolpaths. Toolpaths are the specific routes that the CNC router’s cutting tool will follow to produce the desired shapes and details.
  2. Cutting Parameters: In the CAM software, you can define cutting parameters such as feed rates, spindle speeds, and tool changes. These settings are critical for achieving the desired quality and efficiency in the routing process.
  3. Simulation and Verification: CAM software often provides simulation features, allowing you to preview the tool’s movements and verify that the cutting process matches the design without errors.
  4. Post-Processing: The CAM software generates G-codes, which are the numerical instructions that the CNC router follows. These G-codes are saved on a file that can be loaded into the CNC router’s control system.

Material Preparation

Material preparation is a crucial step in the CNC routing process that can significantly impact the final outcome of the project. Before any cutting or shaping can occur, it is essential to adequately prepare the material. This involves selecting the right type of material for the job, ensuring it is flat and free from imperfections, and securing it securely to the CNC router bed.

One aspect often overlooked during material preparation is considering its grain direction. Depending on the type of material being used, such as wood or MDF, understanding its grain direction can affect how it will react to cutting forces. By aligning the grain properly with the tool path, you can minimise tear-out and obtain cleaner edges in your finished workpiece.

Another critical aspect of material preparation is determining its moisture content. Wood tends to expand and contract with changes in humidity levels if not properly dried before use. It’s important to check that your material has an appropriate moisture content for CNC routing to prevent warping or cracking during and after the machining processes.

Tool Selection

When it comes to CNC routing, tool selection plays a crucial role in achieving optimal results. With various types of tools available, each with its own unique characteristics and capabilities, choosing the right tool for the job is essential.

One key consideration in tool selection is the material that will be routed. Different materials require different types of tools to ensure clean and precise cuts. For example, cutting wood may require a different type of tool than cutting plastic or metal. Additionally, the thickness and hardness of the material also play a role in determining which tool is most suitable.

Another important factor to consider is the desired outcome or finish. Some projects may call for smooth and polished edges, while others may benefit from textured or patterned finishes. The choice of router bit can greatly impact these outcomes. Straight bits, spiral bits, chamfer bits, and many other specialised bits are available today to give users a wide range of options when it comes to achieving their desired finish.

Zero Point Setup

Zero Point Setup is a revolutionary technique that enhances the efficiency of CNC routing. Traditionally, setting up a CNC router involves aligning the workpiece and clamping it in place using various manual methods. This process is time-consuming and prone to errors. However, with Zero Point Setup, these challenges are overcome by utilising modular components equipped with quick-release mechanisms.

The key advantage of Zero Point Setup is its ability to reduce setup times significantly. By simply attaching the pre-aligned module to the machine bed, operators can effortlessly switch between different workpieces without requiring extensive readjustments. This not only saves time but also improves productivity by allowing for uninterrupted machining operations. Additionally, eliminating manual clamping eliminates errors associated with misalignment or uneven pressure distribution.

Moreover, Zero Point Setup empowers operators to achieve higher precision levels in their CNC routing projects. The modules used in this method are accurately machined and easily interchangeable, ensuring consistent alignment every time they are replaced or reattached. Furthermore, by minimising human intervention during setup processes, Zero Point Setup reduces the chances of operator-induced mistakes that could compromise cutting accuracy.

Machine Setup

The machine setup phase in CNC routing is a pivotal step where you configure various parameters of the CNC router to ensure it operates optimally and produces the desired results. This setup involves adjusting critical factors such as spindle speed, feed rate, and cutting depth. Here’s a closer look at these configurations:

  • Spindle Speed: The spindle speed, measured in rotations per minute (RPM), determines how fast the cutting tool rotates during the routing process.
  • Feed Rate: The feed rate determines how quickly the cutting tool moves along the material’s surface. It plays a crucial role in the quality of the cut and the efficiency of the routing process.
  • Cutting Depth: The cutting depth refers to how deep the cutting tool penetrates into the material during each pass.

Proper machine setup is essential for achieving the desired quality and efficiency in CNC routing. These parameters should be adjusted based on the material, tool, and cutting operation to ensure the CNC router produces accurate and precise results while preserving the tool’s integrity.

Toolpath Execution

Toolpath execution is the process of converting the design data, typically created in Computer-Aided Design (CAD) software, into a series of precise instructions that guide the CNC router’s movements. These instructions, known as G-codes, provide information on the tool’s position, speed, and direction throughout all the cutting out process. Toolpath execution is the bridge that enables the CNC router to produce intricate shapes, patterns, and details based on the design.

It is the backbone of CNC routing, translating digital designs into physical creations with precision, efficiency, and accuracy. The quality of toolpath execution significantly impacts the final product, influencing its accuracy, surface finish, cutting efficiency, material utilisation, complexity of cuts, error reduction, and overall consistency. Careful consideration of toolpath strategies and adherence to best practices are crucial for achieving the desired outcomes in CNC routing projects.

Cutting/Routing Process

One of the most crucial steps in CNC routing is the cutting routing process. This process involves precisely cutting out shapes and patterns from a wide variety range of materials, such as wood, plastic, or metal. While it may seem simple at first glance, there are various factors that make this step incredibly important for achieving precise and accurate results.

Firstly, the choice of cutting tool plays a significant role in the overall quality of the finished product. Different materials require different types of tools, ranging from straight bits to spiral bits or ball-nose bits. The selection of the appropriate tool depends on factors like material hardness and desired finish. Additionally, the speed at which the tool moves across the material also needs to be calibrated properly to avoid any errors or inconsistencies in cutting depth.

Moreover, implementing advanced cutting strategies can greatly enhance efficiency and productivity during CNC routing. Techniques like pocketing or profiling allow for faster removal of excess material while ensuring smooth edges and precise contours. By utilising these strategies effectively, manufacturers can minimise waste material and optimise production time.

Safety and Precautions

Safety is paramount in CNC routing, and there are several measures and precautions that operators and workers should adhere to in order to protect themselves and ensure a safe working environment. Two essential safety measures are eye protection and hearing protection, as both CNC machines and routers can generate hazards related to flying debris and noise. Let’s explore these safety considerations in detail:

Eye Protection:

  • Safety Glasses or Goggles: When operating a CNC router, operators and anyone in the vicinity should wear safety glasses or goggles with impact-resistant lenses. These protective eyewear items shield the eyes from flying chips, dust, and debris that can be generated during the cutting and routing process.
  • Face Shields: In cases where there’s a significant risk of larger debris or sharp objects being expelled, additional protection in the form of a face shield may be necessary. Face shields offer comprehensive protection for the entire face and can be worn in conjunction with safety glasses.
  • Eye Wash Stations: Having accessible eye wash stations in the work area is also advisable. In the event of an eye injury or exposure to harmful substances, quick access to an eye wash station can mitigate potential harm.

Hearing Protection:

  • Hearing Protection Devices: CNC routers can generate substantial noise, especially during high-speed cutting and routing operations. Operators and those working in proximity to the machine should wear hearing protection devices, such as earmuffs or earplugs, to reduce the risk of hearing damage. It’s important to choose hearing protection with an appropriate noise reduction rating (NRR) to adequately attenuate the noise.
  • Limit Exposure Time: Reducing exposure time to high noise levels is another effective strategy. Operators should take breaks to limit the duration of noise exposure and allow their ears to recover.

Quality Control

Quality control is a crucial aspect of using CNC milling machines and routing that ensures the end product is held to high standards. It involves rigorous checks and inspections at various stages of the manufacturing process to ensure accuracy, precision, and consistency. One key component of quality control in CNC routing is material inspection. This involves carefully examining the raw materials before they are used, and checking for imperfections or abnormalities that could affect the final product’s integrity.

Another critical aspect of quality control in CNC routing is dimensional accuracy checks. These checks ensure that every cut, hole, or shape created by the machine meets the intended specifications. To achieve this level of precision, specialised measuring tools such as callipers or laser measurement systems are used to verify exact dimensions and tolerances. Additionally, visual inspections play a vital role in quality control, allowing operators to identify any cosmetic flaws such as scratches or blemishes on finished parts.

Maintenance and recording

Maintenance and recording are crucial aspects of CNC routing that often get overlooked. Regular maintenance not only keeps the machine in optimal condition but also ensures a longer lifespan. This includes cleaning, lubricating, and inspecting components for any signs of wear or damage. Maintaining a proper record of maintenance tasks is equally important as it helps to track the machine’s performance over time and identify any recurring issues.

Recording is not limited to maintenance alone; it also extends to documenting production runs, tool changes, and troubleshooting processes. By maintaining detailed records, operators can easily reference past jobs for future reference or replications. This documentation becomes especially valuable when troubleshooting technical glitches or addressing customer concerns regarding specific products. Additionally, analyzing these records will provide insights into efficiency improvements such as reducing material waste or identifying bottlenecks in the workflow.


CNC routing is a versatile and precise manufacturing process that has revolutionised the way we create various products. Its ability to cut through materials with incredible precision and speed makes it an invaluable tool in industries like woodworking, aerospace, and signage. Additionally, automation and computer control systems greatly reduce human error and increase efficiency.

Overall, CNC routing has changed the landscape of manufacturing by providing accurate and efficient production processes. It saves time, reduces material waste, and allows for intricate designs that were previously difficult to achieve manually. As technology continues to evolve, we can expect even greater innovations in CNC routing that will further enhance productivity and expand its applications across various industries. So if you’re looking to take your manufacturing process to the next level, consider incorporating CNC routing into your workflow – it’s a game-changer!

21st November 2023