What are the Different Types of CNC Machining Processes?

CNC machines are not singular entities, but rather a collection of diverse types of CNC machines that are utilized for a variety of machining processes. Several commonly used CNC machining operations are:

CNC Milling

CNC milling is widely recognized as a highly favored form of CNC machining. In fact, numerous proficient machine shops frequently employ CNC machining and CNC milling processes interchangeably. Among the various CNC mill applications, face milling and peripheral milling are notably prevalent.

In a CNC milling machine, the workpiece undergoes material removal as rotating cutting tools move in relation to it.

The milling tool, also known as the cutting tool, is securely attached to a spindle that has the capability to rotate. By utilizing the rotation and movement of the spindle, CNC milling machines are able to execute milling operations involving three or more axes.

CNC Drilling

The process of CNC drilling is much easier compared to the utilization of milling tools or the turning process. In CNC drilling, the workpiece remains fixed while a drill bit traverses over it, forming holes.

Drilling holes serves various purposes such as installing screw bolts, meeting aesthetic needs, or fulfilling other functional requirements.

CNC Grinding

CNC grinding machines utilize a flat abrasive wheel that rotates to eliminate material from the surfaces of rough workpieces. This method is commonly employed to produce a finely finished component, with the grinding wheel spinning at a significantly high velocity.

CNC Routing

CNC routers and CNC milling machines share many similarities. However, the key distinction lies in the fact that in a CNC router, the workpiece remains stationary while the cutting tool moves along the X, Y, and Z axes. This unique setup allows CNC routers to achieve faster cuts compared to milling machines, all while maintaining precision and accommodating intricate designs.

Other Types of CNC Machines and CNC Operations

In addition to the aforementioned types, there exist several other CNC processes as well. Certain autonomous fabrication machines have been incorporated with a CNC system to enable automatic movement. A few examples of these supplementary CNC machines include:

Broaching

Broaching employs a toothed cutting head to form specialized shapes on a workpiece. The cuts made by broaching are remarkably uniform and exceedingly precise. These machines can either be linear or rotary, utilizing a rotating toothed cutting tool.

Sawing

Sawing involves the use of a serrated blade to produce straight and linear cuts. These cuts are made by removing material through the friction caused by the saw blade. When combined with CNC technology, this method is commonly employed for the automated cutting of various materials.

Honing

Honing is akin to grinding as it is typically employed for the secondary refinement of a material. During honing, an abrasive stone or wheel is utilized to precisely grind the workpiece, resulting in the desired shape, size, or finish.

Lapping

Lapping bears resemblance to grinding as it aims to achieve a smooth surface finish. However, unlike grinding which employs a grinding wheel, lapping involves the utilization of an abrasive paste, powder, or mixture. This abrasive mixture is placed between two materials, with one of them being the workpiece, and subsequently, they are rubbed against each other.

CNC lathes

CNC lathes serve as essential tools for shaping metal or wood through machining. Within a lathe machine, the workpiece undergoes rotation around a central axis, while the machining head moves linearly across the surface. With their capabilities, CNC lathes can execute a range of functions including cutting, drilling, sanding, knurling, facing, and more. In comparison to manual lathes, CNC lathes exhibit superior performance.

Plasma Cutters

Plasma cutters represent an advanced iteration of cutting technology, employing a high-temperature plasma jet for material cutting purposes. The plasma is generated through an electrical arc, making this technique suitable exclusively for conductive materials.

Laser Cutters

Laser cutters employ a laser beam to slice through various materials. Unlike plasma cutting, laser cutting is not restricted to electrically conductive substances. By adjusting the laser parameters, laser beams possess the capability to cut through any material.

Flame Cutters

Flame cutting involves the use of an Oxy-acetylene (also referred to as Oxy-fuel) gas mixture to effectively cut metals. By narrowing and igniting the Oxy-fuel stream, a high-temperature flame is produced, allowing for easy metal cutting.

Press Brakes

Press Brakes are designed to facilitate the bending of metal plates and sheets. This is achieved by positioning the material between a die that is either V-shaped or U-shaped. Subsequently, the die is pressed, effectively producing the desired bend.

Electric Discharge Machines (EDM)

EDMs, also known as Electrical Discharge Machines, are utilized for the purpose of cutting conductive materials. In this process, a cutting head emits electrical pulses in close proximity to the material, thereby generating an electrical arc. The arc effectively melts and eliminates the material at the designated position, ultimately resulting in a precise cut.

Water Jet Cutters

Waterjet cutters employ extremely high-pressure water to perform the cutting process. They have the capability to cut through a variety of materials such as metal, alloy, wood, stone, and glass. The movement of the water jet stream is precisely controlled by CNC technology and guided by the software.

Selecting the right CNC machine for the jo

It is crucial to determine the most appropriate type of machine for the specific parts when manufacturing CNC machined components.

It can be challenging to locate a comprehensive range of CNC machines in a single location, as each machine has its advantages and disadvantages. However, one might have better luck finding such a collection at a machine trade show or a CNC shop that is willing to make substantial investments.

In case the optimal machine is unavailable, it is necessary to devise a method to produce the parts using the machines that are accessible. Below are clarifications regarding vertical versus horizontal milling and turning machines.

Figuring out the best way to load the workpieces

Once you have selected the CNC machine for producing your parts, the subsequent crucial step is determining the optimal method for loading your workpieces before proceeding with programming. In my view, this phase holds greater significance than creating the tool paths. However, based on my observations, many machinists encounter challenges at this stage, impeding their progress in a seamless manner.

As a company specializing in prototype machining, we strive to recruit individuals with a flexible mindset and the ability to problem-solve within this field, as we encounter various CNC parts on a daily basis. (Naturally, there are instances where certain individuals resign from their positions within a fortnight!) Explore the diverse CNC workholding techniques available.

Knowing what type of cutting tool to use

Once the machines have been selected and the optimal method for producing the parts has been determined, the correct choice of cutting tools is essential for achieving improved tolerance and surface finish quality. Essentially, the use of appropriate cutting tools leads to enhanced components.

For instance, the process of milling ribs with draft could consume a significant amount of time if conventional sphere cutting tools are used. However, by employing a taper cutter, the same task can be completed in a matter of minutes.

Consider the amount of time you could potentially save by milling 10 or more pieces. Discover the distinctions among various types of CNC cutting and machining tools.