Milling is one of the most commonly used machining methods in mechanical processing. It is mainly used for end milling and contour milling, as well as drilling, extension, reaming, boring and tapping of parts. Parts applicable to CNC milling include:
(1) Flat parts
The characteristic of flat parts is that each machined surface can be flat. At present, most parts processed on CNC milling machines are flat parts. Flattened parts are the simplest type of NC machining, which can usually be processed by two-axis linkage machining (i.e. two-axis half-coordinate machining) of three-axis CNC milling machine.
(2) Variable tilt parts
The parts with changing angles between the machined surface and the horizontal plane are called variable angle parts. When machining variable tilt parts, it is better to use a 4-axis or 5-axis CNC milling machine for angle machining. If there is no such machine tool, the 2-axis half-control line machining can produce approximate values on the 3-axis CNC milling machine, but the accuracy is slightly lower.
(3) Surface (3D) parts
The parts whose machining surface is a space surface are called surface parts. The machined surfaces of curved parts and milling cutters are always in point contact. Generally, 3-axis CNC milling machine is used for processing. There are two common processing methods:
A. The machining adopts 2-axis semi-linkage wire cutting method. Tangent method is to connect only two coordinates in the processing process, and the other coordinates are carried out periodically with a certain line spacing. This method is usually used to deal with less complex space surfaces.
B. 3-axis linkage processing. The milling machine used must have the X, Y and Z 3-axis linkage processing function to carry out spatial linear interpolation. This method is often used to deal with more complex space surfaces, such as engines or molds.