4-Axis Milling & Machining

4-axis milling is an advanced machining process used to shape and finish thermoset composite materials like G10/FR4 and GPO-3. This process utilizes a CNC milling machine that moves along four axes: side-to-side (X-axis), front-to-back (Y-axis), up-and-down (Z-axis), and rotational movement around the X-axis (A-axis).

In 4-axis milling, the spindle, which holds the cutting tool, is oriented vertically, similar to 3-axis milling. However, the addition of the A-axis allows the workpiece to rotate, providing access to more complex geometries and reducing the need for multiple setups. This rotation enables machining on the sides of the workpiece, which is particularly beneficial for parts with intricate details and features.

Thermoset composites like G10/FR4 and GPO-3 are strong, resistant to heat and chemicals, and excellent insulators (see why engineers choose thermosets). These properties make them ideal for electrical and mechanical applications.

When machining thermoset materials, it’s important to choose the right tools. Because thermoset composites are abrasive, tools made from durable materials like diamond-coated or carbide are preferred. High spindle speeds (18,000 – 24,000 RPM) and proper feed rates are crucial to avoid excessive tool wear or damage to the material. Also, dust collection systems are essential to manage the fine dust produced during machining, which can be harmful to both the machine and the operators.

Operations in 4-axis milling include drilling precise holes for fasteners or electrical components, milling to create flat surfaces and slots, cutting to produce sharp angles and intricate patterns, and rotary milling to machine cylindrical or complex shapes. See some fabricated parts made with thermosets and thermoplastics that Atlas Fibre has fabricated in our Component Showcase.

This method has several advantages. It offers greater flexibility and precision compared to 3-axis milling, allowing for the creation of more complex shapes in a single setup. This reduces the potential for errors and setup time, enhancing overall efficiency.

Applications of 4-axis milling include making electrical insulation components like circuit boards and insulators from G10/FR4, and creating mechanical parts that need high strength and durability. Additionally, it is suitable for producing complex geometries in aerospace, automotive, and medical device industries.

4-axis milling is a versatile and advanced method for processing thermoset composite materials like G10/FR4 and GPO-3, offering enhanced precision and efficiency for a variety of applications.

Connect with Atlas Fibre to learn more about our materials and our CNC machining capabilities.