CNC machining is a manufacturing process, which apply programmed computer software to control factory tools and machinery movement in producing way. Complex machinery range from grinders, lathes, mills to routers can be controlled in this process. With CNC marching, a single set of prompts can accomplish three-dimensional cutting tasks.
CNC is short for Computer Numerical Control, which has less limitations compare to manual control, and thereby has excellent advantages to supersede manual option. it never need operators to prompt and guide machining tools commands by levers, buttons and wheels. Although CNC system is always recognized as regular set of computer components. The software programs and consoles in CNC machining distinguish it form other computation forms.
CNC Machining Overview Process
CNC machining utilizes computerized controls to operate and manipulate machines and cutting tools, in order to shape stock material into custom parts as design. Although CNC machining process has different capabilities and operations, the fundamental principles are same throughout all processes. The basic CNC machining stages as following:
- CAD model designing
- CAD file converting
- CNC machine setup
- CNC machining operation execution
CAD model designing
2D vector or 3D part CAD design is the first step of CNC machining, which can be finished in-house or CAD/CAM design service company. Computer-aided design (CAD) software can assist designers and manufacturers create products model or rendering, as well as necessary technical specifications of dimensions and geometries.
CNC machining design should be limited by capability of CNC machines and tooling. For example, most CNC cutting tools are cylindrical, so final machined parts geometries should be cured corner sections via CNC machining. In addition, material properties, tooling design and holding capacity of machine will further limit design possibility, such as minimum thickness, minimum size, complexity of internal cavities and features.
CAD file converting
Finished CAD design runs through computer-aided manufacturing program to extract products geometry. Then generate digital programming code, which is applied to control CNC machine and manipulate cutting tools. Finally, create custom design products.
CNC machines use several programming language like G-code and M-code. G-code as general or geometric code, will control machine tool movement across work-pieces in time, location and direction. M-code as miscellaneous function code, will control auxiliary functions of machine.
CNC machine setup
Before CNC machining program running, we must prepare CNC machine setup. All these setups includes fixing work-pieces directly into machine, on machinery spindles, or into machine vises. Attaching required cutting tools like drill bits, end mills or proper machine components.
Machining operation execution
CNC program instruct CNC machine integrated computer to dictate tools actions and movement. In order to manipulate machine cutting tools. All program prompts will be initiated at start, and guide machine through operation process to produce final parts.
CNC Machine Programming
In CNC machining process, CNC machines are operated by numerical software programs. The language of CNC machining program is called as G-code, it is applied to control behaviors of corresponding machine. Basically, CNC machining involves little human operators in process, it can ore-program cutting tools speed and position, and operate them by software with repetitive and predictable cycles. Its high capability ensure that this technology are adopted in all manufacturing section, especially in metal and plastic production.
Open/Closed-Loop machining system
Different position control will determine open-loop or closed-loop system. In former, signal operate between controller and motor with single direction. While in closed-loop system, controller can receive feedback from motors, which can rectify velocity and position irregularities.
In CNC machining process, cutting tools movement is normally across X axis or Y axis direction. These tools are positioned and guided by servo motors or stepper, which follow detail movement of G-code determination. Open-loop always run in minimum force and speed situation. However, closed-loop is required for industrial applications to ensure speed, consistency and accuracy.
Automatic CNC machining
All CNC producing processes are automated by software programs. Computer=aided design(CAD) can set all dimensions for final design parts, then computer aided manufacturing(CAM) software will converted raw materials into actual finished parts.
As each work piece need a variety of machine tools like drills and cutters to finish all milling and turning process. In order to accommodate these requirement, CNC machines always combine several different function tools into one cell.
CNC machining working Principle
Once a CNC system is activated, desired cutting processes are programmed into software, which will dictate corresponding tools and machinery. Final creates specific parts with accurate dimension.
In CNC programming process, code generator within numerical system always assume flawless of mechanism. Even there are error possibility, specially for more than one direction to cut simultaneously. Part program in numerical control program outlines placement of cutting tools.
CNC system has more expansive computational capacity, in reason of its code is written and edited by programmers. In addition, which can be retained in computers’ memory. Best of all, CNC system can add new prompts to pre-existing programs through revised code, we can update and adjust our programs freely for desired requirement in new projects.
CNC machining operations
CNC machining is suitable for a wide industries, like automotive, construction and agriculture. This process is consist of different computer-controlled machining operations, such as mechanical, chemical, electrical, and thermal. In order to remove necessary material form work-piece to create final custom parts. The most common mechanical CNC machining operation including:
Drilling is a machining process, which use multiple-point drill bits to produce cylindrical holes in work-piece. In CNC machining, CNC machines typically feed rotating drill bit perpendicularly to work-pieces surface and produce vertical holes. However, angular drilling operations can be performed with special machine configurations and holding devices. Drilling operation process including counter-boring, counter-sinking, reaming and tapping.
Milling use rotating cutting tools to remove material from work-pieces. In CNC milling, CNC machine typically feed work-pieces to cutting tools with same direction as tools rotation. Milling operation process including face milling, peripheral milling.
Turning use single-point cutting tools to remove material form rotating work-pieces. In CNC turning, CNC machine as lathe or turning machine will feed cutting tools in linear motion on rotating work-pieces surface, remove material around circumference until required diameter. In order to produce cylindrical parts with external and internal features. Turing operation process including boring, facing, grooving and thread cutting.
In addition, Runsom has other mechanical CNC machining operation including: Broaching, Sawing, Grinding, Honing, Lapping.
CNC Machining Equipment
The earliest numerical control machine apply motors to control pre-existing tools. While new technology enhance with analog computers and ultimate with digital computers, which result to CNC machining rise. The majority of CNC are completely electronic now, common CNC operation including ultrasonic welding, hole-punching and laser cutting. Our normal CNC system including as following:
CNC Drilling Equipment
There are several types of drill bits with special applications, spotting drills for shallow or pilot holes, peck drills for reducing chips on work-pieces, screw machine drills for holes without pilot, chucking reamers for enlarging produced holes. CNC drilling is special designed to utilize CNC-enable drill press. However, this operation can be performed by turning, tapping, or milling machines.
CNC Milling Equipment
CNC mills are operating with number and letter prompts on programs, and guiding pieces in different distance. Mill machines programs based on both G-code and unique language by manufacturing team. Basic mills have three-axis system (X-axis, Y-axis and Z-axis), while advanced new miller will be accommodated with three additional axis.
CNC Turning Equipment
Lathes machines can cut pieces in circular direction with index cutting tools. CNC lathes can produce precise complex parts with high velocity, which are impossible on manual ways. Overall, it has similar control functions as CNC mills, lathes are directed by G-code or unique code. However, most CNC lathes has only tow axis of X and Z.
As there are different kind of 5 axis machines, we can divide them into following 5 types:
- Double swivel head form, two rotation coordinates control on cutter axes.
- Droop swivel head form, two coordinated axes are not perpendicular to linear axis on cutter top.
- Double swivel head form, two coordinates control space rotation.
- Droop table, two axes are not perpendicular to axis on table.
- One swing, one rotate form, two rotation coordinates on cutter and work-pieces.
5-axis CNC machining is able to manufacture CNC parts with complex geometries, high tolerance and excellent surface.
CNC Machine Application
CNC system is widely used in high detailed cutting of metal pieces for industry hardware products. Except aforementioned machines, further tools and components in CNC system also including: Embroidery machines, Wood routers, Turret punchers, Wire-bending machines, Foam cutters, Laser cutters, Cylindrical grinders, Glass cutters. Once complex cutting process in various level and angle, it is easy to performed on CNC machines in minutes. According to specific design, right programs will encourage CNC machines carry out required products with detail and technological value.
CNC machining process is widely used for various engineering materials, including metal (aluminum, brass, stainless steel, alloys), plastic (PEEK, PTFE, Nylon), wood, foam, composites. Optimal materials for CNC manufacturing depend on its application and specifications, which can withstand machining process by its sufficient hardness, tensile strength, shear strength, chemical and temperature resistance. Work-pieces physical properties determine optimal cutting speed, feed rate and depth.
Custom Precision Parts Manufacturing
CNC machining is a critical functions in manufacturing sector, for precision computer parts and fasteners to auto and aerospace components. With out high-tech CNC machines, various components would be impossible to produce, our advanced CNC technology guarantee us producing any complex shape metal mold with highest accuracy.
In the past 10 years, we have satisfied thousands of clients across the industry, we understand the importance of parts quality and precision. Runsom resolve all customers issues in CNC machining process, our high experience in various tools and process of CNC machining.