Best CNC Milling Machine for Metal

Definition.

A CNC milling machine is an automated milling machine with a CNC (Computer Numerical Control) controller used to cut 2D/3D shapes or mill patterns in a variety of materials. CNC milling is a computer numerically controlled method of machining, similar to engraving, cutting, boring and drilling, that enables many of the operations of a CNC milling and boring machine. Computer-controlled milling machines use rotating cylindrical tools that can move along multiple axes to machine a variety of shapes, slots and holes. In addition, the workpiece usually moves in different directions on the milling cutter.

A CNC milling machine is a high precision machining tool suite that works with a computerised digital controller to drive the milling cutter along the tool path to cut CAD/CAM designed shapes or contours, and is an upgraded version of the handheld milling machine. CNC milling machines can perform drilling, boring, tapping, 2D and 3D milling. The most popular milling machines include vertical milling machines and horizontal milling machines that perform three, four or five-axis linkages for cutting and milling aluminium, brass, copper, iron and steel, and are fitted with high-powered spindle motors and servo motors to ensure high spindle speeds for improved precision, accuracy and tolerances in the machining of metal parts. Computer controlled milling machines are suitable for aerospace parts, automotive parts, mould making, machine parts, train parts and shipbuilding parts. Automatic computer controlled milling machines with tool changers are also known as CNC machining centres.

Principle

CNC milling machines are grouped according to the number of axes operated, which are labelled with different letters. x and y indicate horizontal movement of the workpiece (back-and-forth and side-to-side movement on a flat surface). z stands for vertical or up-and-down movement, while w stands for diagonal movement in a vertical plane. Most large and small miniature milling machines offer 3 to 5 axes, providing at least X, Y, and Z-axis performance. High-end automated milling machines, such as 5-axis CNC milling machines, require computer numerical control programming for optimum performance because of the extremely complex geometry involved in automated milling. These machines are very useful because they are able to machine shapes that would be nearly impossible to machine using hand tooling methods. Computer-controlled milling machines also incorporate a machine tool that provides a cutting fluid pump for the tool during the machining process.

Computerised CNC milling machines can be used to produce a wide range of components, and the cost of the tooling involved is becoming increasingly affordable. Generally, high volume production requiring relatively simple designs is best served by other methods, although CNC machining can meet a wide range of production needs. CNC milling machines are the ideal solution for everything from prototyping and short-run production of complex components to the manufacture of unique precision parts.

Basically, any material that can be engraved or cut can be machined with an automated milling machine, although most of the work is done in metal. As with engraving and cutting, the right milling machine must be selected for each material to avoid possible problems. The hardness of the material and the rotation of the milling machine must be taken into account before starting the process.

Types

CNC milling machines are classified into vertical and horizontal types based on the axial direction of the spindle. These machines are also categorised as ram, knee, planer and fabrication or bed types. Most of the automated milling machines are equipped with complete computerised digital controllers, variable spindles, electric drive motors, cooling systems and motorised table feeds. CNC milling machines are classified as vertical milling machines, horizontal milling machines, turret milling machines, bed milling machines, and multi-axis (3-axis, 4-axis, 5-axis) milling machines.

Applications

The CNC milling machine can be used for engraving, carving, milling, cutting and drilling of most metal materials, including copper, aluminium, steel, iron and brass, as well as non-metallic materials such as wood, foam and plastic. It is widely used in injection moulds, iron moulds, metal moulds, shoe moulds, drip moulds, watch parts, zinc electrodes, copper electrodes, automobiles, metal electrodes, metal handicrafts, jade, metal art, jewellery, dental crowns and other forming industries. It is especially suitable for batch milling moulds, watches, glasses, panels, brands, badges, smooth external surface treatment, 3D graphics and text, which can easily form 2D or 3D relief on various materials.