What Is CNC Machining And CNC Machines?

by FORSUN CNC mechanic

CNC machine tools manufacture parts for almost every industry. They are made of plastic, metal, aluminum, wood, and many other hard materials. CNC machining is the process of using a computer-driven machine tool to make parts with different shapes from solid materials. So, what do you know about CNC machine tools?

What Is CNC Machining?

The CNC process is the abbreviation of “computer numerical control”, which contrasts with the limitations of manual control, thus replacing the limitations of manual control. In manual control, the on-site operator is required to prompt and guide the processing through joysticks, buttons, and wheels Tool commands. To the onlooker, a CNC system might resemble a regular set of computer components, but the software programs and consoles employed in CNC machining distinguish it from all other forms of computation.

What Is A CNC Machine?

CNC stands for “Computer Numerical Control”. These machines represent the manufacturing processes used to control various complex tasks.

CNC machining is used in many different industries. It is most common in metal and plastic production.

Basically, CNC machining is a manufacturing process. The computer software is pre-programmed and can tell the machine how to move factory tools and machinery.

A CNC machine allows a set of prompts to complete three-dimensional cutting tasks. This means that it requires almost no manual operation.

Once the programming is written into the machine, the CNC machine will run by itself. The speed and position of machinery and related tools are run by software. CNC machines operate like robots.

How Do CNC Machines Work?

CNC machine tools follow the instructions of pre-programmed computer software. The program specifies the speed, movement, and position of the machine to achieve a specific material shape. The CNC machining process includes the following steps:

Working in CAD: Designers use computer-aided design (CAD) software to create 2D or 3D engineering drawings. The file includes specifications such as structure and dimensions, which will tell the CNC machine how to create the part.

Convert CAD files to CNC code: As CAD files can be used in many applications, designers need to convert CAD drawings into CNC compatible files. They can use programs such as computer-aided manufacturing (CAM) software to change the CAD format to CNC format.

Machine preparation: After operators have readable files, they can set up the machine by themselves. They connect the appropriate workpieces and tools to make the program execute correctly.

Process execution: After the files and machine tools are prepared, the CNC operator can execute the final process. They start the program and then guide the machine through the whole process.

When designers and operators complete this process correctly, CNC machine tools can perform their tasks efficiently and accurately.

What Are The Different Types Of CNC Machines?

CNC Router

A CNC router machine is a computer numerically controlled machine tool that is very similar to the commonly used handheld router machines used to cut various materials. This CNC machine can cut and engrave wood, metal, or plastic, and is a very common type of CNC machine.

CNC router machine can also be called a computer numerical control router machine, CNC engraving machine, CNC cutting machine, CNC engraving machine, and CNC drilling machine. The CNC engraving machine has the ability to effectively produce one-off parts and reproduce similar parts. It can produce outstanding high-quality jobs while increasing the overall productivity of the plant. CNC machines have been innovated to ensure a high degree of automation and precise work.

Common CNC engraving machine applications: furniture manufacturing, cabinet manufacturing, sign making, handicraft and art, mold manufacturing and prototyping, construction wood products, foam cutting, metal processing, plastic processing, etc.

CNC Lathes

Operated with Computer Numerical Control (CNC) systems and provided with precise design instructions, CNC Lathes are machine tools where the material or part is clamped and rotated by the main spindle, while the cutting tool that works on the material, is mounted and moved in the various axis.

CNC Lathes are normally used for machining parts, where the material/part is clamped and rotated whereas the cutting tool is stationarily mounted for OD (Outer Diameter) and ID (Inner Diameter) operations, e.g. shafts and pipes. They are ideal for parts that have the same symmetry around an axis that could be chucked up (i.e. radially clamped) in the spindle.

A simple CNC Lathe operates on 2-axis and the tool is located in a fixed position at 8 to 24 station turret. The rotating action of the part is called “turning”, hence certain types of CNC Lathes are called CNC Turning Machines.

Milling (cutting tool moves around stationery workpiece), boring, and tapping (a tool that cuts threads inside the hole) tools are normally driven by a separate drive system inside the turret. Depending on the application, the life tools (i.e. active tools) are mounted for axial or radial operational directions. These could be found in 3-axis CNC Lathes or CNC Turning Machines.

Lathe machines with additional options such as Y-axis, sub-spindles, or specific selected options for automation are commonly called Turning Centres. These sophisticated machine tools are capable of machining complex parts – these go beyond standard OD & ID turning operations and may incorporate milling, drilling, and tapping operations to complete the part in one sitting. Taking a piece from raw part to finished product, such all-in-one machine tools significantly improves productivity.

CNC Laser Cutter

As the name suggests, laser cutting machines create patterns and designs by cutting through materials. The powerful laser beam is the source of melting, burning, or vaporizing materials.

Essentially, laser cutting is a manufacturing process that uses a thin focused laser beam to cut and etch materials into custom designs, patterns, and shapes specified by the designer. This heat-based non-contact manufacturing process is very suitable for a variety of materials, including wood, glass, paper, metal, plastic, and gems. It is also capable of producing complex parts without the need for custom-designed tools.

Water Jet Cutters

A water jet is a machine composed of three main components, which uses high-pressure water to erode the fine lines in a piece of material. Depending on the density and compound of the material (such as titanium), granular abrasives are added to the water jet to improve cutting ability. Abrasive is added to the nozzle so that it is possible to simply switch between water and abrasive cutting.

CNC Plasma Cutter

Plasma cutting is the process of cutting conductive materials through accelerated thermal plasma flow. Typical materials that can be cut with a plasma torch are steel, stainless steel, aluminum, brass, copper, and other conductive metals. Plasma cutting is widely used in manufacturing, automobile repair, and restoration, industrial construction, salvage, and scrapping. Due to the fast cutting speed, low cost, and high precision, plasma cutting has been widely used from large industrial CNC applications to small amateur companies.

CNC Milling Machines

CNC milling is a certain type of CNC machining. Milling is a process that is quite similar to drilling or cutting, and milling can perform these processes for a variety of production needs. Milling utilizes a cylindrical cutting tool that can rotate in various directions. Unlike traditional drilling, a milling cutter can move along multiple axes. It also has the capability to create a wide array of shapes, slots, holes, and other necessary impressions. Plus, the workpiece of a CNC mill can be moved across the milling tool in specific directions. A drill is only able to achieve a single-axis motion, which limits its overall production capability.

CNC mills are often grouped by the number of axes on which they can operate. Each axis is labeled using a specific letter. For example, the X and Y axes represent the horizontal movement of the mill’s workpiece. The Z-axis designates vertical movement. The W axis represents the diagonal movement across the vertical plane.

The majority of CNC milling machines offer from 3 to 5 axes. More advanced mills must be programmed with CAM technology to run properly. These advanced CNC machines can produce specific shapes that are basically impossible to produce with any manual tooling techniques. In addition, most CNC mills are equipped with a special device that pumps fluid to the cutting tool during the production process.

All in all, CNC machining, as a reliable and useful part production method, has consolidated its position in the manufacturing industry. At the same time, compared with other manufacturing methods, CNC machining costs can often be higher.