Different Types of CNC Machine Tools and Their Applications: A Comprehensive Guide

Overview of CNC Machine Tools

CNC machines play a vital role in today’s manufacturing industry. CNC machines are automated tools that use computer programming to control their movement and operation. They are widely used in the manufacturing process to produce precise, complex parts with high accuracy and efficiency. CNC stands for Computer Numerical Control, and when computers are used to control CNC machines, they are called CNC machines. In simple terms, CNC machines control the movement of tools and workpieces through computer-aided design (CAD) and computer-aided manufacturing (CAM) programs to create almost any custom shape imaginable.
This blog will take an in-depth look at the types of CNC machines, including their definitions, how they work, their pros and cons, and tips for choosing the best type.

1.Working principle of CNC machine tools

CNC machines automatically cut raw materials based on digital instructions from CAM or CAD software. First, the CAD software creates a 3D model of the desired part, which is then loaded into the CAM software, generating a set of computer instructions (g-code) that control the sequence of tool movement on the workpiece.
G-code includes part feature coordinates, required tools, speeds and feeds, and coolant control commands. The machine control unit (MCU) converts the g-code into instructions for the servo motors and spindles, and the CNC machine moves the tool or workpiece on multiple axes to cut the raw material into the desired shape.

2.Composition of CNC machine tool system

CNC machine tool systems consist of several basic components that work together to achieve precise and automated machining operations:

1.Input devices: load CNC programs onto the machine tool, such as keyboards, USB flash drives, or wireless communication devices.

2.Machine tools: physical devices that perform the actual machining operations, there are different types such as lathes and milling machines, usually with slides and spindles, which are controlled in the X, Y, and Z axis directions.

3.Machine control unit (MCU): the brain of the system, receiving instructions and converting them into precise movements and actions of the machine tool, managing parameters such as motion control, spindle speed, and tool changes.

4.Servo motors: drive the machine tool axes, receive MCU signals, and provide precise and controlled movements.

5.Feedback devices: such as encoders or linear scales, work with servo motors to provide position feedback to the MCU to ensure accuracy.

6.Tools: include a variety of cutting tools and accessories, selected according to the machining operation and material.

7.Workholding devices: hold the workpiece in place during machining, there are many types such as vises and clamps.

8.Operator interface: allows the operator to interact with the CNC system to enter commands, monitor progress and adjust parameters.

3.Different types of CNC machine tools

1.CNC milling machine
Principle: Use cutting tools to remove material from the workpiece and shape it accurately. The workpiece is usually fixed and the tool rotates at high speed. There are vertical and horizontal configurations. The vertical milling machine spindle is vertical, and the horizontal milling machine spindle is horizontal, which can accommodate larger workpieces.
Application: Used in the manufacture of cabinets, furniture, prototype models, etc., can produce complex shapes, high precision and versatility.

2.Turning CNC machine tool
Principle: By rotating the workpiece material, cutting and shaping with cutting tools. Including turret lathes, engine lathes, etc., can perform a variety of processing operations.
Application: Suitable for manufacturing symmetrical parts such as camshafts and automotive parts.

3.EDM CNC machine tool
Principle: Use electric sparks to remove material from conductive workpieces. There are two main types: wire cutting and sinking EDM.
Application: Manufacture injection molds, die castings, etc., suitable for conductive materials, can cut complex shapes with high precision.

4.CNC water jet cutting machine
Principle: Use high-pressure water jets mixed with abrasives to accurately cut various materials.
Application: Suitable for cutting parts in industries such as aerospace and automobiles, without heat damage, but slower speed, suitable for thick materials.

5.CNC Grinding Machine
Principle: Use a rotating grinding wheel to remove material to achieve high precision and surface finish.
Application: Used for processing parts such as camshafts and ball bearings, commonly used in industries such as automobiles and aerospace.

6.CNC Drilling Machine
Principle: Use a rotating drill bit to drill holes in the material.
Application: High efficiency, suitable for industries such as automobiles and mold manufacturing, but cannot drill deep or large holes, and specific drill bits are required for drilling holes of different diameters.

7.3D Printer
Principle: Print objects layer by layer, and designs and drawings are created through CAD and CAM processes.
Application: Commonly used for prototyping.

8.Multi-axis CNC Machine Tools
Multi-axis machine tools are more precise and can produce more accurate parts, providing machinists with more processing options.

9.Automatic Tool Changing CNC Machine Tools
Tools can be automatically changed to improve production efficiency and reduce downtime.

4.Types of CNC machine tools classified by the number of axes

2-axis CNC machine: The most basic CNC system, with two moving axes, usually performs basic cutting or drilling, and operates fixed workpieces.
3-axis CNC machine: The most common form, can produce 2.5-dimensional parts, has three moving axes, can operate on six surfaces of a traditional block of material, but requires repositioning the workpiece.
4-axis CNC machine: In addition to the X, Y, and Z axes, there is also a rotation axis A, which can create curved cuts.
5-axis CNC machine: There is a rotary movement axis C of the tool or table, which can operate the workpiece on five surfaces without repositioning, producing complex and precise parts.
6-axis CNC machine: Adds a third rotational direction B axis to produce a variety of shapes.
7-axis CNC machine: Has three moving tool axes, three rotating workpiece axes, and a seventh axis E, which can produce complex parts.
9-axis CNC machine: Consists of a 5-axis milling machine and a 4-axis lathe, which can produce internal and external features of parts.
12-axis CNC machine: the most sophisticated equipment, with two cutting heads that can move along six axes, increasing precision and productivity.

5.Advantages and disadvantages of CNC machine tools

1.Advantages:
Can be operated without human intervention.
High productivity.
High precision and repeatability.
Can produce parts with small dimensional deviations.
Can manufacture parts with complex features.
CNC programs are easy to modify.
Reduces the risk of human error and improves safety.

2.Disadvantages:
Costs higher than manual machine tools.
Requires expensive skilled labor to operate.
Requires regular maintenance.
Maintenance downtime can disrupt production schedules and increase costs.

6.Tips for choosing the best CNC machine type

1.Identify the application and manufacturing process requirements and determine the required functions.

2.Consider the size of the part and ensure that the machine can accommodate it within its working range.

3.Determine the required level of accuracy and select a machine with high rigidity and precision components.

4.Ensure that the machine can process the materials planned to be used.

5.Evaluate the production requirements and select appropriate functions such as fast traverse and automatic tool change.

6.Consider whether multi-axis processing of complex 3D shapes is required.

7.Choose a reliable and high-precision brand.

8.Prioritize easy-to-use control interfaces and compatible software.

9.Look for suppliers who provide training and technical support.

10.Ensure that technicians can repair and spare parts are available.

11.Check the machine power requirements and adjust the workplace.

7. Conclusion

As a key equipment in modern manufacturing, CNC machine tools have greatly improved production efficiency and product quality with their computer-controlled accuracy and automation. They can automate many manufacturing operations that were originally completed manually, increase production while reducing waste, and effectively reduce the possibility of human error.