CNC Milling is a machining process that uses computer-controlled rotary cutters to remove material from a workpiece, shaping it into a desired form. In CNC milling, the workpiece is usually held stationary, while the cutting tool moves along multiple axes (typically 3, 4, or 5 axes) to carve intricate designs and features with high precision.

Tool offset in CNC milling refers to the adjustment made to account for the position and dimensions of the cutting tool. It compensates for the tool’s length, diameter, and wear, ensuring precise positioning of the tool relative to the workpiece. Tool offsets are essential for accurate machining because they allow the CNC machine to calculate the exact tool path needed to achieve the desired dimensions of the part.

5-axis CNC machining is a manufacturing process where a CNC machine moves a cutting tool or workpiece along five different axes simultaneously. Unlike traditional 3-axis machining, which moves only along the X, Y, and Z axes, 5-axis machining adds two additional rotational axes (A and B). This allows for more complex part geometries, better surface finishes, and greater flexibility in positioning the workpiece.

The main differences between a CNC router and a CNC mill relate to their design, applications, and capabilities:

1. Purpose and Application:

   • CNC Router: Primarily designed for cutting, carving, and shaping softer materials like wood, plastics, and composites. It is commonly used for sign-making, furniture, and intricate designs in non-metal materials.
   • CNC Mill: Built for working with harder materials, such as metals (steel, aluminum), and performs precision machining on complex parts for industries like aerospace, automotive, and manufacturing.

2. Cutting Speed:

   • CNC Router: Typically operates at higher spindle speeds (20,000+ RPM), allowing it to quickly cut softer materials.
   • CNC Mill: Operates at lower spindle speeds (up to 15,000 RPM) but with greater torque, enabling it to handle denser materials like metals.

3. Machine Design:

   • CNC Router: Has a lighter, more open-frame design and often a larger working area to accommodate large sheets of material.
   • CNC Mill: Features a more rigid, heavy-duty structure, allowing for greater precision and the ability to handle harder materials without vibration.

4. Axes and Motion:

   • CNC Router: Typically uses 3-axis motion (X, Y, Z) but may include more axes for complex routing.
   • CNC Mill: Offers more sophisticated 3, 4, or 5-axis motion, ideal for machining complex 3D shapes and high-precision components.

Metals: CNC mills can work with a range of metals, from softer ones like aluminum and brass to harder ones like steel, stainless steel and titanium. These machines are often used in industries such as automotive, aerospace, and metal fabrication to create precise metal parts.

Plastics: CNC mills can also shape various plastic materials, including acrylic, PVC, polyethylene, and nylon, among others. These plastics are often used in the manufacture of medical devices, consumer products, and electronic components.

Composite materials: CNC mills can machine composites, which are a combination of materials such as carbon fiber, fiberglass, and Kevlar. These composites are often used in the aerospace, automotive, and sporting goods industries.

Ceramics: CNC mills can precisely shape and cut various types of ceramics, including alumina, zirconia, silicon carbide and silicon nitride. Due to the brittle nature of ceramics, the milling process requires special attention to factors such as cutting speed, tool selection and cooling to prevent cracking or chipping of the material.