What is the purpose of a spindle in a CNC milling machine?

The spindle's primary function in a CNC milling machine is to hold and rotate the cutting tool at high speeds. This rotation is essential for the milling process, as it enables the cutting tool to effectively remove material from the workpiece. By spinning at varying speeds, depending on the material being machined and the desired finish, the spindle allows for precise cutting and shaping of the workpiece. The capability to adjust spindle speed is critical for optimizing cutting conditions and ensuring the tool can handle different materials and operations efficiently.

While cooling the workpiece, providing electrical power, and stabilizing the machine are important aspects of CNC milling, they do not define the spindle's core purpose. Cooling systems can help manage heat generated during milling, but they are separate components. Likewise, electrical power is supplied to the entire machine, not specifically through the spindle. Stability is provided by the machine structure and setup, but again, this is not the spindle's role. Thus, the spindle's design and function as the component that directly engages with the cutting tool is what makes it indispensable in the milling process.