What is CNC technology?
CNC stands for "computer numerical control" and means that the machine is controlled by a set of commands issued by a controller. The command code issued by the controller is usually in the form of a list of coordinates, called a G code. Any machine controlled by such code can be called a CNC machine, including mills, lathes and even plasma cutters. In this article, we will focus on the different types of CNC mills and lathes and their combinations.
CNC Lathe – This type of lathe works by spinning material in the lathe's chuck. The tool then moves in 2 axes, cutting out the cylindrical part. CNC lathes are able to form curved surfaces, while manual lathes are difficult or even impossible to form curved surfaces. The tool is usually non-rotating, but may be movable if it is a power tool.
CNC Mills – CNC mills are typically used to make flat parts, but more complex machines have more degrees of freedom and are capable of producing complex shapes. The material is stationary and the spindle rotates with the tool, which moves along 3 axes to cut the material. In some cases, the spindle is stationary while the material moves.
CNC Drilling – This machine is similar to a CNC mill, but it is designed to cut in only one axis, that is, it only drills down into the material along the Z axis and never cuts along the X and Y axes. .
CNC Grinder – This machine brings the grinding wheel into contact with the material, producing a high-quality surface. It is designed to remove small amounts of material from hard metals; thus it is used as a surface preparation operation.
Subtractive manufacturing
CNC machining produces parts through subtractive manufacturing. This type of processing basically removes material from a solid blank to ultimately form the desired shape. It can be done by any of the methods we mentioned above, such as milling, turning, grinding or drilling. Additive manufacturing is the opposite process, where materials are added from scratch to form parts, such as 3D printing.
Work Clothes
Tooling performs all cutting work. Tools are usually mounted on tool racks or loaded onto spindles as needed. Many different tools are used in the process of making complete parts, and there is no one-size-fits-all manufacturing method. Below is a list of tools commonly used in typical machining operations.
Milling Tools
End Mill – An end mill is a common tool that is usually capable of cutting in 3 directions. It is divided into different styles, such as flat head, fillet radius, ball head and tapered shank, etc.; with different number of edges, helix angle, base material and coating material.
Face Milling Cutters – Face milling cutters can cut large surface areas, which is called face milling. Its cutting edge is usually on the tool edge, and the milling teeth are usually carbide blades.
Thread Milling Cutter – A thread milling cutter creates threads by rotating in a threaded pattern around an axis, cutting out the thread shape.
Notch Cutters – Use these cutters to create T-shaped slots along the length of a part. Due to the geometry of this tool, it must enter and exit from the open end of the material.
Lathe Tools
Outside Diameter Turning – As the name suggests, this type of tooling is designed to make cuts on the outside diameter of a component. It may be a solid tooling that machines the part into the desired shape, or it may be a carbide insert.
ID Grooving and Threading – These tools are typically thin and have the ability to drill into the part and either groov the ID or form threads inside.
Cut-off – Cut-off tools are used to cut off parts as a final operation after all other operations are completed.
Drilling – Used to drill holes in the longitudinal direction of a part that must be reamed or drilled out to achieve final tolerances.
Work Equipment Materials
Tool types can be further subdivided according to the material of the tool itself. Common workwear materials are listed below:
High Carbon Steel – It is the lowest cost machining tool and does not last long. It loses hardness at temperatures around 200°C.
High Speed Steel (HSS) – This is more commonly used than carbon steel tools because it lasts longer and does not lose hardness until 600°C, allowing it to cut at faster speeds.
Carbide – Carbide tools are harder than HSS, but are less rigid and may break if not handled properly. It can withstand temperatures up to 900°C.
Ceramic – These cutting tools are extremely hard and are typically only used to cut hard materials at very high temperatures. It comes in two common materials, aluminum nitride and silicon nitride.
Cubic Boron Nitride – Ideal for hardening steels and high-temperature alloys, these tools offer excellent friction and thermal resistance.
