Five of the Most Common Precision CNC Machining Methods

CNC machining is a general term used for a variety of machining applications. "CNC" stands for computer numerical control and refers to the programmable features of a machine that allow the machine to perform many functions with minimal human control. CNC machining is the manufacture of parts using CNC controlled machines. The term describes a range of subtraction manufacturing processes in which material is removed from rod or wool to produce finished parts. There are 5 different types of CNC equipment to perform 5 common types of CNC precision machining.

CNC precision machining is widely used in medical, aerospace, industrial, oil and gas, hydraulic, and other industries. CNC machining can be performed on a variety of materials, including metal, plastic, glass, composite materials and wood.

Precision CNC machining has many advantages over machining without CNC programmable capabilities. It can significantly reduce machining cycle time, improve surface smoothness, and improve quality and consistency.

Here are five of the most common precision CNC machining methods:

1 - CNC lathe machining

CNC lathes are characterized by the ability to rotate (turn) materials during machining operations. The cutting tool of the lathe is fed in linear motion along the rotating bar material; This removes the material around the circumference until the desired diameter and characteristics are achieved.

A subset of CNC lathes is the CNC Swiss lathes (also called automatic cars). With a CNC Swiss lathe, the bar material rotates and axially slides through the guide bushing into the automatic lathe, which then automatically machines the cut parts. In general, CNC automatic cars are suitable for machining small diameter parts.

CNC lathe machining can create internal and external features on parts: including drilling, broaching, reaming, grooving, tapping, threading. CNC lathes and turning centers manufacture parts including screws, bolts, shafts, joints and more.

2 - CNC milling machine machining

The CNC milling machine features the ability to rotate the cutting tool while keeping the material workpiece/block stationary. They can produce a variety of shapes, including plane milling (shallow, flat surfaces and cavities in the workpiece) and peripheral milling (deep cavities, such as slots and threads).

Parts suitable for production on CNC milling machines are usually square or rectangular shapes with various characteristics.

3 - CNC laser processing

CNC laser machines have a pointed router with a highly focused laser beam for precise cutting, slicing, or engraving of materials. The laser heats the material and causes it to melt or vaporize, creating a cut in the material. Usually, the material is sheet-like. The laser beam moves back and forth across the material to create a precise cut.

Compared to traditional cutting equipment (lathes, turning centers, milling machines), this process can result in a wider range of free designs and often produces notches and/or edges that do not require additional finishing processes.

CNC laser engraving machines are commonly used to mark (and decorate) parts. For example, it is difficult to process logos and company names with CNC turning or CNC milling processes. However, it is very easy to carve with a CNC laser, and even after the machining operation is complete, you can use laser engraving to add it to the component.

4 - CNC Electrical Discharge Machining (EDM)

CNC discharge machining (EDM) uses highly controlled electrical sparks to process materials into the desired shape. It can also be called spark corrosion, spark machining, or wire burning.

A component is placed under the electrode and the machine is programmed to send out a discharge from the wire, generating intense heat (up to 11,700C). The material is melted or washed away by the liquid to create the desired shape or feature.

EDM is most commonly used to create precise microhole, slot, cone, or angular features in a part or workpiece and a variety of other more complex features. It is usually used for machining difficult shapes and sizes, and is usually used for machining very hard metals. Like gears.

5 - CNC plasma cutting machine

CNC plasma cutters are also used to cut materials. However, they do this using a high-power plasma (electron-ionized gas) torch controlled by a computer. Similar in function to a handheld pneumatic torch used for welding (up to 5,500 degrees Celsius), the plasma torch can reach up to 27,500 degrees Celsius. The plasma torch melts through the workpiece to create incisions in the material.

Whenever CNC plasma cutting is used, the material being cut must be electrically conductive. Typical materials are conductive metals such as steel, stainless steel, aluminum, brass and copper.

Precision CNC machining provides a wide range of production capabilities for manufacturing components and finishing. Depending on the environment of use, materials required, lead time, quantity, budget, and features required, there is usually one best way to deliver the desired results.