Definition and Characteristics of Face Milling
Face milling is a process that uses a cutting tool with teeth on its surface to machine a flat surface. Unlike end milling or peripheral milling, which rely on the tool's side edges for cutting, this process utilizes the tool's end face for cutting. This results in faster surface machining efficiency while ensuring a higher degree of flatness and a superior surface finish. Face milling is particularly well-suited for machining large, flat parts and is compatible with a wide range of materials, including steel, aluminum, and plastic. The process is typically performed on vertical or horizontal CNC (Computer Numerical Control) machines and is widely used for surface smoothing, finishing, and preparing parts for subsequent machining.
Alternative Names for Face Milling
Face milling is sometimes referred to as "surface milling," a term often used when emphasis is placed on surface finish. However, in professional machining, "face milling" is the standard term and should be distinguished from "end milling"-end milling primarily relies on the tool's periphery, not the end face, for cutting.
Face Milling Process
Face milling is a multi-step process that requires precise equipment setup and parameter control to achieve a smooth, high-quality machined surface. Its typical operating principle is as follows:
Workpiece Fixture
The workpiece is securely clamped to the machine table, typically in a vise with parallel jaws, ensuring the workpiece is positioned at the correct height. Workpiece stability and clamping flatness are crucial for consistent cutting during this stage.
Tool Positioning
The face milling cutter is aligned so that the spindle axis is perpendicular to the workpiece surface. The Z-axis height can be adjusted based on the desired depth of cut: generally, a shallower depth of cut is used for finishing and a deeper depth of cut is used for roughing.
Parameter Setup
The spindle speed and feed rate are programmed based on the material type, tool diameter, and depth of cut. For harder materials or deeper cuts, lower speeds and feed rates are typically required to avoid excessive tool wear or vibration during machining. Cutting Execution
On CNC machines, tool paths are controlled by pre-programmed G-code, ensuring precise and repeatable tool movements. In manual milling, the operator feeds the tool across the workpiece surface at a controlled speed. During the cutting process, the tool removes material with its end insert, resulting in a smooth, even surface with each milling pass.
