Sinostar MACH's CNC machining technology combined with casting and forging processes can meet customers' parts requirements

What is CNC Machining

A CNC machine is a ‘Computer Numerical Control’ machine, a versatile, high-precision and high-efficiency machining machine that is indispensable for the production of customised parts and products in modern manufacturing. The process works on a wide range of materials, including metal, plastic, wood and glass.

CNC machining is widely used in industries such as large-scale manufacturing, telecoms parts and prototypes, and aerospace, where extremely tight tolerances are critical.

Next, Sinostar MACH will share the characteristics of CNC machining technology based on years of manufacturing experience.

CAD File Conversion

Formatted CAD design files are run through a programme, usually computer-aided manufacturing (CAM) software, to extract the part geometry and generate the digital programming code, which will control the CNC machine and manipulate the tooling to produce the custom-designed part.

CNC machines use several programming languages, including G-code and M-code.

Once the CNC program is generated, the operator loads it to the CNC machine.

Machine Setup

Before running the CNC program, the operator must prepare the CNC machine for operation. This involves affixing the workpiece directly into the machine, onto machinery spindles, or into machine vises or similar work-holding devices and attaching the required tooling, such as drill bits and end mills, to the proper machine components. The next step is to accurately locate the zero reference point, also known as the origin or work offset, as defined in the CNC program. This alignment ensures the program corresponds to the physical positioning of the workpiece. Finally, the operator must verify that all machine settings and offsets match the CNC program’s requirements and confirm that all components are securely fastened. Once these preparations are complete, the CNC program can be executed.

Machining Operation Execution

The CNC program serves as a set of instructions for the CNC machine, providing commands that dictate the tooling’s actions and movements. These commands are processed by the machine’s integrated computer, which operates and manipulates the machine tooling accordingly. When the program is initiated, the CNC machine begins the machining process, following the program’s guidance to execute the necessary operations required to produce a custom-designed part or product.

Some of the most common mechanical CNC machining operations, including:

1.Drilling is a machining process that employs multi-point drill bits to produce cylindrical holes in the workpiece. In CNC drilling, the CNC machine feeds the rotating drill bit perpendicularly to the plane of the workpiece’s surface, which produces vertically-aligned holes with diameters equal to the diameter of the drill bit employed for the drilling operation.

2.Milling is a machining process which employs rotating multi-point cutting tools to remove material from the workpiece. In CNC milling, the CNC machine typically feeds the workpiece to the cutting tool in the same direction as the cutting tool’s rotation, whereas in manual milling the machine feeds the workpiece in the opposite direction to the cutting tool’s rotation.

3. Turning is a machining process that employs single-point cutting tools to remove material from the rotating workpiece. In CNC turning, the machine—typically a CNC lathe machine—feeds the cutting tool in a linear motion along the surface of the rotating workpiece, removing material around the circumference until the desired diameter is achieved, to produce cylindrical parts with external and internal features, such as slots, tapers, and threads. Operational capabilities of the turning process include boring, facing, grooving, and thread cutting. 

Types of CNC Machining Support Software

The CNC machining process leverages software applications to enhance the precision and accuracy of custom-designed parts or products. Key software applications commonly used include:

1.CAD software is used to draft and create 2D vector or 3D solid models and surface renderings. It is also used to generate the technical documentation and specifications required for the manufacturing parts. CAD programs typically interface with CAM software to translate designs into machine programs for CNC machining.

2.CAM software is used to extract technical data from CAD models and generate machine programs that control CNC machinery. It automates the manipulation of tooling to produce custom-design parts. Key advantages of CAM software include enabling CNC machines to operate with minimal operator assistance and automating post-machining evaluations of finished products.

3. CAE software is used to support engineers during the pre-processing, analysis, and post-processing phases of product development. It assists in design,

What is a CNC Machine?

Depending on the machining operation being performed, the CNC machining process employs a variety of CNC machines and machine tools to produce the custom-designed part or product. While the specific type of machine used depends on the machining operation, all CNC machines share the commonality of computer-controlled precision.

What is a Desktop CNC Machine

Companies specializing in CNC machines often produce a desktop series of compact, lightweight machines designed for smaller applications. While these machines are slower and less precise than larger industrial models, they are well-suited for working with softer materials like plastic and foam. Desktop CNC machines are ideal for creating smaller parts and handling light to moderate production tasks.

These machines often mimic the functionality of their larger counterparts but in a more compact form factor.

When working with smaller lathes, it’s essential to distinguish between benchtop CNC lathes and desktop lathes. Benchtop CNC lathes are generally more affordable but also smaller and somewhat limited in the applications they can handle. A standard CNC benchtop lathe includes typically the motion controller, cables, and basic software. A standard CNC desktop lathe costs slightly more with a similar basic package.

CNC Machining Materials

The CNC machining process is suitable for a variety of engineering materials, including:

Metal (e.g., aluminum, brass, stainless steel, alloy steel, etc.)

Plastic (e.g., PEEK, PTFE, nylon, etc.)

Wood

Foam

Composites

The optimal material for selection to apply to a CNC manufacturing application largely depends on the particular application and its specifications. Most materials can be machined if they can withstand the machining process—i.e., have sufficient hardness, tensile strength, shear strength, and chemical and temperature resistance.

The workpiece material and its physical properties are used to determine the optimal cutting speed, cutting feed rate, and depth of cut. Measured in surface feet per minute, the cutting speed refers to how fast the machine tool cuts into or removes material from the workpiece. The feed rate—measured in inches per minute—measures how fast the workpiece is fed toward the machine tool, and the cut depth is how deep the cutting tool cuts into the workpiece. Typically, the workpiece will first undergo an initial phase in which it is roughly machined to the approximate, custom-designed shape and dimensions and then undertake a finishing phase in which it experiences slower feed rates and shallower cut depths to achieve its more precise and accurate specifications.

CNC Size Considerations

The wide range of capabilities and operations offered by the CNC machining process helps it find applications in various industries, including automotive, aerospace, construction, and agriculture. It enables it to produce a range of products, such as hydraulic components, screws, and shafts. Despite the versatility and customizability of the process, manufacturing some parts—e.g., large or heavy components—presents greater challenges than others.