If you want to fully understand CNC machining guide, read this guide: it will take you through all aspects of CNC machining faster with in-depth explanations.
Whether you’re new to the CNC machining industry or an expert in CNC machining, this guide will take you through CNC machining in detail.
What Is Cnc Machining?
CNC machining is a method of controlling machine tools to machine parts using digital control technology. CNC machining sends out instructions through a computer to allow the CNC machine tool to follow a predetermined program to complete the machining of the part（That’s Computer Numerical Control）.
Cnc Machining History
In 1952, the U.S. Massachusetts Institute of Technology developed the world’s first successful CNC machine tool, which marks the birth of CNC technology.
The development of CNC machining has roughly 4 stages:
The First Stage:
this stage is mainly focused on the transformation and development of machine tools. This stage of although the level of technology is relatively low, the function and performance of CNC machine tools are limited, but for the automated processing of traditional machine tools to provide new ideas and methods.
The Second Stage:
from the 1960s to the 1970s is the period of rapid development of CNC technology. With the progress of computer technology, the function and performance of CNC systems have been greatly improved, at the same time, the scope of application of CNC machine tools has also been expanded from metal processing to the processing of wood, plastics and other materials in the field.
The Third Stage:
from the 1980s to the 1990s is the stage of comprehensive popularization and application of CNC technology. Because CNC technology has matured, the field of application continues to expand, widely used in aerospace, automobile manufacturing, electronic equipment and other industries to greatly improve product quality and production efficiency.
From The 21st Century,
CNC technology further integration of advanced manufacturing technologies, such as artificial intelligence, Internet of Things. A new generation of CNC systems have a higher degree of intelligence, flexibility and adaptability, and can realize more complex processing tasks.
How Does CNC Machining Work?
The basic principle of CNC machining is to enter the workpiece processing requirements into the computer, the computer-controlled machine tool in accordance with a predetermined program for processing. The specific workflow is as follows:
Design Product Drawings:
First, according to the requirements of the product and design drawings（Commonly used design software: CAD Software）, to determine the shape, size and processing technology.
Prepare Machining Program:
According to the product drawings and machining requirements, prepare the machining program. The machining program is composed of a series of instructions to control the CNC machine tool for machining operations.
Input Machining Program:
input the written machining program into the control system of the CNC machine tool. Usually use U disk, Ethernet and other ways for file transfer.
Setting Processing Parameters:
According to the processing requirements of the product, set the processing parameters of the CNC machine tool, such as cutting speed, feed speed, tool sharpening conditions.
Machining Process Control:
start the CNC machine, the machine according to the input processing program for automatic processing, the computer through the control system to control the movement of each axis to achieve the control of the machining path.
Detection Of Machining Results:
After machining is completed, check whether the size and quality of the product meet the requirements through measurement and testing means.
Types Of CNC Machining
Turning
Turning is a cutting method in which the workpiece rotates as the main motion and the turning tool moves as the feed motion.
Milling
Milling is a machining method that uses a milling cutter as a tool to machine the surface of an object.
Drilling
Drilling is an operation in which a drill is used to create holes in solid material.
Grinding
Grinding is a machining method that removes material. It refers to a machining method that removes excess material from a workpiece with an abrasive, an abrasive tool.
Wire Cutting
EDM wire cutting is referred to as wire cutting. It is developed on the basis of EDM piercing and forming. It not only makes the application of electric discharge machining has been developed, and some aspects have replaced the electric discharge piercing, forming processing.
Processes For CNC Machining
CNC machining process is the use of CNC machine tools to process parts by using a variety of methods and technical means of the sum: applied to the entire CNC machining process.
CNC machining process is accompanied by the emergence of CNC machine tools, the development and gradual improvement of an application of technology; it is a large number of CNC machining practice of people’s experience.
CNC Machining Materials
CNC Machining Commonly Used Metal Materials
Aluminum: lightweight, good thermal conductivity, easy to work with and malleable.
Stainless steel: corrosion-resistant, high strength, suitable for a variety of applications.
Steel: high strength, wear resistant, suitable for structural and mechanical parts.
Copper: good electrical and thermal conductivity, suitable for electronic and conductive parts.
Titanium: high strength, corrosion resistant, suitable for aerospace and medical fields.
Alloy materials (e.g. aluminum alloys, titanium alloys, etc.): combining the characteristics of different metals, with specific strength, corrosion resistance and other characteristics.
Plastic Materials For CNC Machining
ABS: density of 1.2, good toughness, can be bonded, spray oil can be baked to 70-80 degrees.
PMMA: density of 1.3, more broken, good transparency, can be bonded, spray oil can be baked to 65 degrees or so.
PC: density 1.2, can withstand high temperatures of 120 degrees, can be bonded, can spray oil, general transparency.
POM (steel): density 2, high strength and good toughness, can not spray oil, can not be bonded, wear-resistant.
PP: density 1.1, high strength and good toughness, can spray oil, can not be bonded.
Bakelite: density 2, high strength and good toughness, can not spray oil, can not be bonded, can withstand 250 degrees high temperature.
Nylon: density 1.2, high strength and good toughness, can not spray oil, can not be bonded.
475 rubber sheet: density 1.2, relatively soft, poor toughness, can withstand 60-70 degrees high temperature.
Plastic King (PTFE): density 2.2, can not be bonded, can not spray oil, can withstand 250 degrees high temperature, relatively soft.
Advantages Of Cnc Machining
CNC machining precision is relatively high, with a very smooth processing quality, which depends on the choice of the program process, by the program to manipulate, processing precision and quality are very ensure.
CNC machining can also carry out multiple linkage, and at the same time can carry out complex work-like processing, a wide range of applications, processing a variety of products and workpieces.
CNC machining can save the labor cost by choosing the very high automatic level, without hiring a large number of workers.
The application of CNC machining can be a way to enhance productivity, because the processing of parts as long as the change of the CNC machine program flow, saving the production site management time.
CNC machining precision is relatively high, can be processed in large quantities, the immediate end of the order information.
CNC Machining Quality Control
CNC lathe machining control mainly from the production process, on-site production management, finished product shipment inspection aspects of control to ensure product quality.
8.1 The production process is the quality control is quite important, in the CNC machining site production process to develop operating instructions that is SOP, strict implementation to standardize the operation of employees operating the machine. Responsibility for each process to the person, the staff for product self-testing is quite important to carry out layers of checks by the quality of the inspection after passing into the next process, do not manufacture substandard products, to prevent defective products into the production process. Each workshop should be to be inspected, qualified products, unqualified for different areas and clearly labeled to prevent confusion.
8.2 Workshop management products and tools must be neatly placed in the planning area line, keep clean and dry(Reference: OSHA Machinery Safety Operations Manual). In this way, the whole processed parts will be a very high grade. According to the drawing inspection size does not exceed the tolerance, shape and position, plus “clean”, “the appearance of no scratches” in order to say that the completion of a qualified finished product.
8.3 Finished goods shipment inspection, the most important thing is the quality of personnel, the degree of care for the processing of parts, workers in the operation of the various aspects of the operation, if you can do light take light, the completion of the process of the workpiece does not leave metal shavings on the workpiece, the workpiece is divided into areas of neat yardage, and do a good job of the corresponding protective measures to avoid the workpiece to avoid bumping each other, to avoid scratches, and the last process is completed to do a good job of cleaning, packaging to ensure that the parts of the clean and oil-free. Strictly follow the process regulations. Strictly in accordance with the process regulations, seriously do a good job of self-inspection, mutual inspection and final inspection.
CNC Machining Cost
CNC Machining Cost Basics
CNC machining costing refers to the total cost of product processing by calculating the cost of materials, equipment and labor required for processing, as well as manufacturing costs and other possible expenditures. CNC machining cost calculation is an important part of the business activities carried out by the enterprise, for the enterprise to improve efficiency, cost control provides an important reference basis.
CNC Machining Cost Elements
Direct material costs: that is, the cost of materials required for product processing, including raw materials, fuel, labor protection supplies costs.
Direct labor cost: i.e. the cost of workers’ wages, social insurance premiums, housing provident fund, allowances, bonuses and so on.
Manufacturing costs: including depreciation of machines, maintenance costs, equipment utilization costs, water, electricity and gas costs, management costs, etc.
Other expenses: including transportation costs, packaging costs, taxes and so on.
CNC Machining Cost Calculation Method
Calculation of direct material costs: the weight of the material required for CNC machining multiplied by the unit material price can be.
Calculation of direct labor costs: the time required for CNC machining multiplied by the salary level of workers can be.
Calculation of manufacturing costs: just add up the depreciation, maintenance and usage costs of the equipment, or calculate the cost per hour of operation.
Cost accounting: add up all the above costs to get the total cost of CNC machining.
CNC Machining Applications
The following are the main applications of CNC machining technology.
Parts Manufacturing
CNC machining technology can manufacture extremely complex three-dimensional parts, can be produced through CAD or other mechanical design software 3 model, and then through the CAM software to generate CNC program code, and ultimately realize the production of parts. It can realize the manufacture of high-precision parts, thus saving research and development costs and time and improving production efficiency.
Engraving And Decoration
CNC machining technology can realize carving decoration, such as wood carving, stone, plastic carving and so on. As the CNC machining process can precisely control the curve trajectory of the machining head, it can realize complex carving, such as realizing high relief effect, which is more beautiful and fine.
Mold Manufacturing
CNC machining technology can be used to manufacture molds and dies, because molds and dies require high precision, repeatability and batch production, which is the strength of CNC technology. The use of CNC machining technology to manufacture molds and dies can achieve high manufacturing efficiency and larger batch sizes.
Part Finishing
In the field of machining, part finishing usually requires manual processing, such as the use of thwart knife and sandpaper, which may lead to irregular surfaces and complex geometric shapes. The use of CNC machining technology allows these tasks to be realized while ensuring smooth surfaces, high precision and high efficiency.
Automated Production
CNC machining technology can also be used in computer-integrated manufacturing (CDM) or computer-aided manufacturing (CAM) lines. This allows machining production to become fully automated, which reduces production costs, improves productivity and quality, as well as increasing the reliability and consistency of part manufacturing.
Future Trends In CNC Machining
The development trend of CNC machining technology
Accuracy Improvement
CNC machining technology has made significant progress in the past few decades, and the machining accuracy has been greatly improved. However, with the progress of science and technology, people’s demand for product quality increases, the precision of CNC machining technology also needs to be constantly improved.
Composite Machining
Traditional CNC machining can usually only complete a single machining operation, such as milling, turning, etc.. Composite machining is in the same CNC machine tool for a variety of plus J operation, such as milling, drilling, tapping, etc.. The emergence of composite machining will greatly improve productivity and reduce equipment investment and floor space.
Intelligent
With the development of artificial intelligence technology, CNC machining technology is also developing in the direction of intelligence. Intelligent CNC machining equipment can achieve autonomous decision-making(e.g. Industry 4.0 and Smart Manufacturing White Paper), automatic adjustment and online monitoring through learning and optimization algorithms.
High-speed Machining
With the increasingly high requirements of the manufacturing industry for product processing efficiency, high-speed machining technology has emerged. High-speed machining technology by increasing the cutting speed and feed rate to achieve fast, efficient processing of the workpiece.
Machining Complex Surfaces
In the traditional CNC machining, the processing of complex surfaces usually requires multiple tool changes and manual intervention. With the development of CNC machine tools and tool technology, the processing of complex surfaces will become easier.
In summary, the development trend of CNC machining technology includes accuracy improvement, compound machining, intelligence, high-speed machining and machining complex surfaces. These trends will promote the application of CNC machining technology in the manufacturing industry to expand, improve production efficiency and product quality. In the future, CNC machining technology is expected to become an important driving force for the development of the manufacturing industry.
Conclusion
By reading this guide, you have a detailed understanding of CNC machining, if now you want to machine CNC machined parts, please contact us JIEJIA CNC.
At JIEJIA CNC, we will provide you with one-stop CNC machining services to meet your various needs for CNC machining.
FAQS
What are the main types of CNC machining processes?
Common types include milling, turning, grinding, mill-turn and wire EDM.
What materials can be used for CNC machining?
Commonly used metal materials (such as aluminum alloys, steel alloys, copper, titanium alloys, etc.) and plastic materials (such as ABS, PEEK, POM, PA) are widely used.
What are the advantages of CNC machining?
Unrivaled precision and accuracy, increased operational efficiency and productivity, improved quality control and cost effectiveness, improved workplace safety and environment, etc.
How to calculate the cost of CNC machining?
Costs include material costs, labor (CNC machine setup and programming costs), machining time, manufacturing costs, and other factors such as packaging and shipping.
How do I start a CNC machining project?
Prepare detailed design files (CAD or STP), select materials, determine machining quantities, tolerance standards, surface finish requirements, etc., and then contact a trusted CNC machining supplier (e.g., JIEJIA CNC) for consultation and production.
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