Computer numerical control (CNC) machining is an automated machining process that uses precise, computer-controlled parameters to cut materials to desired dimensions. Unlike conventional machining where movement and spindle speeds are controlled manually, CNC machining leverages computer programming to deliver hyper-precise results without significant operator interaction.
The advantages of CNC machining go far beyond cost savings, including higher throughput, accuracy, and repeatability than human-controlled buttons and wheels. The entire machining process for a workpiece can be automated, providing superior consistency and repeatability of dimensions between parts in the same production run.
The Machining Process
Before CNC machining, operators viewed a diagram of a specific part and manually interacted with machinery to attempt to mimic the design. This process is time-consuming, labor-intensive, and requires significant skill, while still lacking the consistency and quality control afforded by automation.
CNC technology typically follows directions generated by computer-aided manufacturing (CAM) software, which develops machining instructions based on a digital design created using computer-aided design (CAD) software. This facilitates precision control a wide range of tooling, including mills, bores, lathes, routers, cutters, and more.
There are a wide variety of CNC machines, each with specific capabilities, advantages, and disadvantages. Determining the most appropriate machine or machines depends entirely on the specifics of the design. Part complexity, materials, specificity, and throughput needs are all considered when selecting CNC machining equipment.
Some of the most common CNC machining processes include:
- CNC milling. Using a spindle containing rotating tooling with multiple points, CNC mills make precision cuts to remove material and achieve the specified design. CNC milling can be done using vertical, horizontal, or multi-axis milling. In a vertical mill, the spindle containing the tooling is mounted vertically, while horizontal mills use tooling on a horizontally mounted spindle. Vertical mills are the most commonly used type of CNC mill and are well-suited to most standard milling projects. Horizontal mills offer more versatility, better chip evacuation, and can handle heavier parts.
- Wire Electrical Discharge Machining (EDM). Wire EDM cuts electrically conductive materials using an electrical discharge contained between two electrodes, with an electrically charged wire acting as the first electrode and the conductive workpiece acting as the second. The spark generated between the wire and the conductive material vaporizes material instead of cutting it. This leads to precise lines that can’t be acquired via other traditional cutting tools.
- Sinker Electrical Discharge Machine. Similar to Wire EDM, Sinker EDM uses an electrical discharge to form parts. Sinker EDM starts by submerging a ferrous alloy in an insulating liquid. An electrode is then submerged into the liquid and powered up to generate a plasma arc. This arc is guided to vaporize material, creating fine lines, shapes, and patterns. CNC sinker EDM operations offer high accuracy, complexity, and speed.
- Metal machining. Metal CNC machining tools are made to cut, stamp, mill, or mold metals. There are a variety of machining processes and associated equipment used to form metal, each with its own advantages and drawbacks. Some of the most common metal machining methods include metal stamping, screw machining, milling, turning, EDM, and grinding.
- Plastic machining. Plastic and metal have different forming and machining requirements. CNC machine tools are available with specialized tooling targeted for cutting and forming plastic parts.
- Waterjet cutters. CNC waterjet cutters offer high throughput, accuracy, and reliability. Waterjet cutters use an extremely high-pressure, focused stream of water to cut materials. Abrasive materials may be added to the water stream to cut through harder materials.
CNC machining has largely overtaken manual machining in many shops, especially those that focus on high-volume production or precision fabrication. Some of the advantages of CNC machining include:
Short Turnaround Times
Conventional machines take additional time and resources to set up and operate. CNC 5-axis machines take less time to set up, create parts faster, and require less operator attention during production. This results in much faster turnaround times and scalability.
The autonomous nature of CNC machines eliminates human error and accuracy issues stemming from operators. Though specific tolerances often vary by machine and project, CNC machining is often capable of achieving extremely tight tolerances.
Fewer technicians and operators are required to execute CNC-enabled automation. Production times are minimized, labor costs are reduced, and production speed and efficiency of CNC machining make it cost-effective. Overall, CNC machining produces superior results at a low cost per part.
Manual machining operations offer little in terms of volume flexibility. CNC equipment can easily be dialed up or down to meet changing volume demands.
CNC machining is one of the most common fabrication methods for its versatile nature. CNC operations are compatible with an expansive range of materials and offer the ability to reliably bring complex design geometries to life.
Applications and Industries
Due to the benefits listed above, CNC machining is used across a wide variety of applications and industries. Here are some examples of applications for CNC machining and CNC parts:
Design & Rapid Prototyping
CNC machining is used regularly during the rapid prototyping phase of design. Due to its nature, CNC machining can quickly iterate ideas and create proof-of-concept models using affordable short-run tooling. CNC provides tight tolerances, real materials, and sample models for inspection, verification, consumer testing, and concept proofing.
CNC machining is one of the primary methods of fabricating molds. From injection molding to blow molding and high-pressure die casting, CNC machining is ideal for rapid, accurate, and consistent mold fabrication. At RAM Tool, our 5-axis CNC mills are capable of fabricating molds quickly and efficiently.
The aerospace industry relies on safety-critical parts within stringent tolerances. CNC machining is the primary method of creating these parts in today’s digitally driven ecosystem. Common aerospace parts created using CNC machining may include:
- Engine components
- Fuel panels
- Landing gear components
- Engine mounts
- Turbine assemblies
The automotive industry relies on rapid production to facilitate Just-in-Time inventory requirements. Automotive manufacturers rely on CAD files and one-off production batches to create custom automotive parts for limited-edition luxury vehicles, prototype vehicles, and repair parts, while more commonly CNC machining operations produce repeatable production of standard vehicle parts and components. CNC machining reduces the cost of these cycles while improving precision and reliability.
Oil & Gas
The oil and gas sector has an elevated focus on quality, precision, and safety. Part failure in these applications can pose severe risks to the equipment itself and the surrounding environment. 4- and 5-axis CNC machines can produce the intricate details need to create precision oil and gas instruments and safety-critical parts.
The results of CNC machining are present on virtually every store shelf. From kitchenware to toys to delicate electronics components, CNC machining helps facilitate the high-volume production of most consumer products.
Custom CNC Machining
Custom, quick-turn, and accurate CNC machining is the cornerstone of many industries. At RAM Tool, we carry vertical, horizontal, high-speed, heavy machining, large machining, and 5-axis machining equipment. We specialize in the production of aluminum and zinc dies used in the die-casting process.
We have over four decades of experience creating tight-tolerance zinc and aluminum casting dies, and we have the equipment to handle jobs as large as 20 tons. Our best-in-class facility houses multiple CNC machining centers, including:
- Large Capacity, High-Speed Horizontal Machining Center
- CNC High-Speed Precision 5-Axis Machining Center
- CNC High-Speed 5-Axis Gantry Type Machining Center
- CNC High-Speed 5-Axis Machining Center
- CNC Horizontal Boring Mill Centers
- CNC Vertical Machining Centers
- CNC High-Speed Vertical Machining Centers
- CNC Carbon Mill Center
- EDM Sinker and Wire Centers
- CNC Toolroom
We also have welders, tempering furnaces, drill presses, scanners, knee mills, surface grinders, and more. We’ve spent decades investing in the right equipment and talent to provide accuracy, reliability, and precision to projects across industry sectors.
Precision CNC Machining From RAM Tool, Inc.
CNC machining is a cost-effective alternative to conventional machining, offering better quality-control, throughput, accuracy, scalability, repeatability, and versatility. At RAM Tool, Inc., we can help you find the right machine and the right talent for every project. Contact us to learn more about our CNC machining capabilities.