Understanding CNC Machining
Computer numeric control (CNC) machining is an automated manufacturing method that uses cutting tools to selectively remove material from a stock piece until the desired shape is achieved. It works by converting a digital model of a part into a sequence of computer instructions that control the actions of the machining tools to achieve the desired output. Since it is computer-controlled, CNC machining can deliver superior levels of versatility, efficiency, and precision relative to other common manufacturing methods. This makes it a popular manufacturing choice for a vast range of industries and applications.
There are various types of CNC machines, each of which has its own unique advantages and capabilities. Different machining possibilities can be achieved depending on the specific machine's capabilities, number of axes, and the orientation of the cutting tools. Some of the most common CNC machining processes include:
CNC Milling uses a rotating multi-point cutter to remove excess material from a workpiece as it is fed to the cutting tool. The rotating cutter can move along different axes with high precision to create parts with complex geometries. Prototypes or final parts can be manufactured quickly with great accuracy and repeatability
Vertical CNC Machining
Vertical CNC machining is a form of milling wherein the spindle axis and associated cutting tools are vertically oriented with respect to the bed of the machine. The cutting tools point downward from the tool holder and are typically used to cut across the top of the workpiece's surface.
Horizontal CNC Machining
Horizontal CNC machining, also a form of milling, uses cutters that are mounted on a horizontal spindle. The cutters come out from the side of the tool holder and cut across the side of the workpiece's surface, allowing chips of material to fall away from the table.
Converse to milling, CNC turning uses a single-point cutter to remove material from a spinning workpiece that is being held in a chuck. A CNC lathe or turning machine feeds the cutter in a linear motion along the rotating workpiece, removing excess material to produce highly accurate round or tubular shapes. Like milling, turning can rapidly create both prototypes and final parts.
Wire Electrical Discharge Machining (EDM)
Wire EDM is used for cutting electrically-conductive materials. An electrically-charged wire held between two mechanical guides acts as one electrode, while the workpiece being cut acts as the second electrode. The electrical discharge generated between the wire and the workpiece creates sparks that cut material away from the workpiece. As there is no cutting force involved, wire EDM is well-suited for producing tiny and delicate parts with intricate details.
Metal CNC machining uses computer-operated cutting tools to selectively remove material away from a metal workpiece, shaping it into the desired configuration. A wide variety of common metals are compatible with CNC machining processes, such as aluminum, copper, and steel.
CNC machining can also be used to create custom-designed components and products from various types of plastic, including acrylics, polycarbonate, polypropylene, and many others. Plastic machining may involve one or more of the above processes, which create design shapes by selectively cutting away materials from a plastic workpiece.
Vertical CNC Machining
Horizontal CNC Machining
Precision Wire EDM
Selecting the right CNC machine for the job
When making CNC machined parts, it is important to figure out which type of machine is most suitable for the parts in question. Every machine has its pros and cons, but it is difficult to find every kind of CNC machine in one place — except maybe at a machine trade show, or in a CNC shop willing to invest lots of money. If the most suitable machine is not available, you need to find a way to make the parts with the machines that are available. Here are some explanations of each type of CNC machine. Check out the pros and cons.
Figuring out the best way to load the workpieces
When you have chosen the CNC machine to make your parts, the next step — before programing — is to find the best way to load your workpieces in order to gain the best machined result. I believe this stage is more important than making the tool paths, but in my experience most machinists have a difficult time with it, and it prevents them from moving forward smoothly. As a prototype machining company, we try to hire people who have an open mind and are able to find solutions in this area, since we come across different CNC parts every day. (Of course, some people quit the job within two weeks!) Check out the different loading methods. Check out the different loading methods.
Knowing what type of cutting tool to use
After choosing the machines and deciding on the best way to make the parts, selecting the right cutting tools will help to achieve a tighter tolerance and better surface finish. In short, suitable cutting tools result in better components. Here’s an example: milling ribs with draft might take hours using normal sphere cutting tools, but would require just a few minutes with a taper cutter. So imagine how much time you could save when milling 10 pieces or more. Find out the differences between types of cutting tool. Find out the differences between types of cutting tool.
Industries & Applications
CNC machining allows for high levels of versatility, precision, and speed, making it a popular manufacturing choice for all types of applications. Industries that frequently benefit from CNC machining include:
High levels of precision and quality are crucial for sensitive applications in the medical field to avoid equipment malfunctions and misdiagnoses. CNC machining benefits the fast-paced medical device sector by enabling rapid prototyping for product testing and validation. It also delivers high-quality end-use components that are utilized in everything from orthotic devices to MRI machines.
The automotive industry benefits from the automation, batch-to-batch consistency, and material flexibility enabled by CNC machining. For example, CNC machining processes produce the metal shafts and gear components that comprise the gearbox of a transmission system. A vehicle's light fixtures are typically manufactured through CNC machining of plastics such as PMMA.
Extreme accuracy and tight tolerances are essential for components that will be used in mission-critical aerospace applications. CNC-machined aerospace components are used in everything from aircraft engines to sophisticated instrument and control panels. CNC machining also benefits the aerospace industry by enabling quick and accurate prototyping for product testing.
Consumer and commercial goods
The ability to provide exceptional repeatability and consistency across high production volumes makes CNC machining perfect for consumer and commercial goods manufacturing. CNC machining is particularly well-suited for new product development, as it allows prototypes to be easily modified and perfected before going into final production.
CNC machining allows for rapid prototyping with the ability to make quick and frequent modifications, which is essential for success in the fast-growing and innovative robotics field. In addition to prototyping, CNC machining can also be used for manufacturing a number of sophisticated robotic parts.
Advantages of CNC Machining
As a machinist, it is important to understand the advantages and disadvantages of CNC machining so that you can identify which projects suit the process. We must help customers optimize their design for CNC machining, or else guide them to another manufacturing processes when it doesn’t suit. As a product designer, it is vitally important to know whether to stick with CNC machining or to design the parts for another manufacturing process. Here are some of the key advantages of CNC machining.
CNC precision machining technologies have revolutionized the manufacturing industry by minimizing manual work and allowing for unparalleled levels of consistency and accuracy. Some of the advantages of CNC machining over other common manufacturing methods include:
CNC machining offers a much greater degree of dimensional precision relative to manual manufacturing processes. As machining operations progress to the finishing stages, material is removed from the workpiece at higher accuracies to achieve extremely tight tolerances.
High production and scalability
Once the design specifications are programmed into the computer software, CNC machining can consistently achieve high production volumes with flexible scalability.
When paired with advanced design software, CNC machining can perform intricate and precise operations that cannot be duplicated by manual machining. This allows for a significantly greater degree of design flexibility, enabling the production of parts of nearly any size, shape, or complexity.
Since CNC equipment is automated, it requires fewer technicians to operate and supervise production tasks.
CNC machining allows each precision-machined part to be perfectly replicated according to exact specifications.
Excellent material properties
CNC machining can be performed on practically any material with sufficient hardness.
The accuracy, speed, efficiency, and automation of CNC machining reduces manufacturing costs by minimizing production times and labor hours. These savings can be passed along to customers, creating a competitive advantage and providing an opportunity for business reinvestment.
Once a design for an object has been loaded into the software, the program is able to retrieve the design at any future date, facilitating additional production runs without the need for new programming.
One-off custom parts and prototypes
CNC machining allows for efficient, on-demand production of one-off parts or prototypes.
CNC machining is a relatively low maintenance process that typically only requires occasional software updates and replacement of cutting tools.
CNC machining allows practically any metal or plastic object imaginable to be created from an extensive selection of materials.
Start Your CNC Project Today
Using computer software to control machining tools, CNC machining has transformed the manufacturing industry by allowing for quick, efficient, and precise production of one-off parts, prototypes, and end products. With a range of different cutting tools and techniques available, CNC machining can be performed in various ways to achieve a nearly infinite variety of outputs.
3ERP is a precision CNC machining and CNC prototyping company with capabilities including milling, turning, wire EDM, aluminum machining, and more. Our skilled machining experts combined with our 3-, 4-, and 5-axis CNC machining capabilities allow us to achieve exceptional levels of precision, quality, and complexity for even the most complex or critical applications. With years of experience in our field, we have the expertise to provide comprehensive precision machining services that meet the standards of myriad industries.