China Shenzhen Perfect Precision Product Co., Ltd. company news

In grinding, the use of superhard abrasive wheels is very common. However, in order to ensure the accuracy and quality of grinding products with superhard abrasive wheels, certain requirements need to be made for superhard abrasive wheels in machining. Superhard abrasive wheels need to reduce vibration, improve machining stability, and avoid machining surface quality and dimensional accuracy errors. Then, what are the requirements for the use of superhard abrasive wheels? Requirements for the use of superhard abrasive wheels 1. The rotation accuracy of the grinding wheel spindle is high. Generally, the axial runout is less than 0.005mm and the radial runout is less than 0.01mm. 2. The grinder should have enough rigidity, which is required to be about 50% higher than that of ordinary grinder. When the static stiffness of the machine tool is increased by 20% The service life of the grinding wheel can be increased by more than 50%. 3. The sealing of the grinder must be reliable, especially the sealing of the headstock spindle and bearing. 4. The accuracy of the feeding mechanism of the grinder should be high, and it should ensure that it is fed evenly and accurately, stable and free of movement, with less than 0.005mm times Feed mechanism. 5. The grinding machine shall be provided with shockproof measures. 2、 Grinding fluid selection requirements In addition to the general grinding requirements for grinding fluid, the particularity of the grinding wheel itself should also be considered in superhard abrasive wheel grinding. Compared with ordinary grinding wheels, its hardness is high, its structure is dense, its pores are few, and it is easy to be blocked in the grinding process. It requires that the grinding fluid has good wettability and cleaning, and its viscosity is small. When using resin bonded grinding wheel, wet grinding can reduce the grinding temperature and reduce the thermal decomposition of the bond near the abrasive particles. Compared with dry grinding, wet grinding can increase the service life of the grinding wheel by about 40% and improve the quality of the machined surface. The grinding fluid for diamond grinding wheels is usually kerosene with strong washability, or light diesel oil or a 1:10 mixture of low-grade machine oil and kerosene. Various water-soluble grinding fluids and weak alkaline emulsions can also be used. Among them, kerosene, diesel oil and water-soluble grinding fluid are better. For example, kerosene is widely used in grinding cemented carbide. If there is a large smoke during grinding, mixed aqueous solution can be used, but emulsion should not be used. Soda water and strong alkaline emulsion should not be used for resin bonded grinding wheel. Its pH should not exceed 9 and the liquid temperature should not exceed 30 ℃. The EP oil grinding fluid used in profile grinding, thread grinding and gear grinding has good effect, which can correspondingly improve the quality of the machined surface, shallow grinding scoring lines, and increase the service life of the grinding wheel. CBN grinding wheels generally do not use water-soluble grinding fluid, but mostly use light mineral oil (kerosene, diesel, etc.). CBN abrasive particles will react with water at high temperature, which is called hydrolysis, which intensifies the wear of abrasives. When aqueous solution is necessary, extreme pressure additives should be added to reduce hydrolysis. If the dry grinding process is adopted for superhard abrasive wheels, the binder and particle size should be appropriately selected, and the back cutting amount and feed amount should be reduced to reduce the grinding temperature. The use requirements of these superhard abrasive wheels need to be strictly observed during grinding. In the process of grinding, it is easy to produce errors due to some external environment. Therefore, processing according to regulations is one of the effective methods to reduce errors and ensure product accuracy.

In metal grinding, it is easy to use metal materials containing chromium, nickel, tungsten, molybdenum, titanium and other elements. These materials are difficult to grind, so they are called difficult to grind materials. There are many kinds of hard to grind materials, and three types are common in general processing. Let's talk about the problems of hard to grind materials in detail. 1、 Types of hard to grind materials The first kind of hard grinding materials have high hardness and toughness, or the hardness is not very high but the toughness is very high, such as commonly used heat-resistant alloys, titanium alloys, stainless steel, high vanadium high-speed steel, etc. The second kind of hard grinding materials are soft and sticky, such as various non-ferrous metals and pure iron used in processing. The third kind of hard grinding material is easy to burn and crack during grinding, or the surface roughness of the workpiece is poor. The measures to solve the above three materials are also different. The second material can be turned with diamond turning tool, and the turning effect is better; For the third kind of material, a suitable grinding wheel can be selected, such as a coarse abrasive wheel with loose structure, a suitable grinding fluid and improved pouring method can achieve better results. 2、 Characteristics of hard to grind materials At present, the first material is difficult to solve in production. This material has the following characteristics in grinding: 1. Workpiece surface is easy to burn The alloy steel used in this kind of hard grinding material has high hardness, toughness, large chip deformation, large cutting resistance and high heat generation. At the same time, due to the poor thermal conductivity of this material, a large amount of heat generated in the grinding area cannot be transferred quickly through effective channels, resulting in high temperature in the grinding area, so it is easy to have surface burns. 3.The grinding wheel is easy to be blocked When grinding this kind of material, the chips are easy to stick on the surface of the grinding wheel, making the grinding wheel lose its cutting ability and difficult to remove from the abrasive particles. The grinding wheel is blocked, the friction between the grinding wheel and the workpiece increases, and the grinding temperature rises sharply, causing workpiece burns. 4 .Workpiece is easy to deform Grinding these hard grinding materials is easier to deform than other steels. Due to the strong work hardening trend of alloy steel materials, residual stress is easy to occur on the workpiece surface during machining. In the later processing process, the workpiece will be deformed due to the change of stress state. For example, when grinding stainless steel slender shafts, they become waist drum shaped and distorted after grinding; The sheet workpiece is warped and uneven; It is easy to produce ellipses when grinding large diameter workpieces. 5.Chill phenomenon Due to the severe extrusion and friction in grinding, the work hardening trend of alloy steel materials is enhanced. Therefore, the cold hardening phenomenon of the ground surface layer is more serious. It will also cause annealing on the surface of the workpiece. In addition to the above grinding defects, the grinding of difficult grinding materials also has the problems of low metal removal rate, low grinding ratio and low durability of grinding wheels. Therefore, in the process of machining difficult grinding materials, it is necessary to understand the difficult grinding materials and solve the problems pertinently to ensure the grinding quality.

Heat treatment technology is essential in metal processing. It can make metal workpiece have the required mechanical properties, physical properties and chemical properties. The processes of metal heat treatment can be roughly divided into three categories: one is overall heat treatment, the other is surface heat treatment and chemical heat treatment. In these three categories, there are also several different heat treatment processes according to the different heating medium, heating temperature and cooling method. In different treatment processes, the same metal can also obtain different structures, resulting in different properties. 1、 What are the heat treatment processes 1. Integral heat treatment As the name suggests, integral heat treatment is a metal heat treatment process that heats the workpiece as a whole, cools it at an appropriate speed after heating, obtains the desired metallographic structure, and changes its overall mechanical properties. Among them, annealing, normalizing, quenching and tempering are the basic processing processes of the overall heat treatment of steel. 2. Chemical heat treatment Chemical heat treatment needs to immerse metal or alloy workpieces into them for heat preservation with the help of active media at a certain temperature, so that the surface of the workpieces can be infiltrated with atoms of one or concentrated chemical elements. Through the three-stage chemical heat treatment process of heating → heat preservation → cooling, the chemical composition, structure and performance of the workpieces can be changed. At the same time, after quenching and low-temperature tempering, the surface of the workpiece can have higher hardness, wear resistance and contact fatigue, and at the same time, it can also ensure that the core has higher strength and toughness. The main change of the workpiece after chemical heat treatment is that the technical parameters have two aspects, one is the depth of the hardened layer, the other is the surface hardness. The former needs to use Vickers hardness tester to detect the distance from the workpiece surface to the hardness reduced to 50HRC, which is the so-called hardening depth. The surface testing of chemical heat-treated workpieces has certain similarities with the hardness testing of surface quenching heat-treated workpieces. They can be tested by Vickers hardness tester, surface Rockwell hardness tester and durometer. Except that the thickness after nitriding is relatively thin. If it is not greater than 0.7mm, Rockwell hardness tester cannot be used. 3. Surface quenching heat treatment Surface quenching is only the quenching of the surface layer of steel parts. Its heat treatment is characterized by the rapid heating method, which quickly heats the surface of steel parts to the quenching temperature, and then quickly cools, so that the surface layer of steel parts can be hardened to a certain depth, while the heart can remain in the original state. Surface quenching heat treatment is mainly carried out by heating or flame heating. The main technical parameters are surface hardness, local hardness and effective hardened layer depth. Vickers hardness tester or Rockwell hardness tester can be used for hardness testing. The selection of test force is directly related to the effective depth of hardened layer and the surface hardness of the workpiece.

I often hear many enterprises complain that there are so few machining orders that I can't find them anywhere. However, the actual situation is not like this. Many enterprises that send out orders are often distressed because they can't find a suitable machining factory. They have a large number of products that need to be processed by someone, but because they don't know the machining supplier, they don't dare to send them out easily. They have to think about which is better in machining. So, how to choose an excellent machining plant? When choosing an excellent machining factory, the channel is very important. We should keep the selectivity at the lowest possible cost, expand the scope to the greatest extent, and one more option will lead to one more advantage. Here we will not introduce the selection channel of machining manufacturers, but mainly how to choose an excellent machining factory. 1. The reputation of the machining plant is the top priority There are all kinds of Companies in the machining market. If you choose a company with bad credit, it is easy to cause some unnecessary trouble after receiving the products. Therefore, in order to work later, when choosing a machining plant, we should first inquire about the reputation of the machining plant. The reputation of the machining plant can be investigated from two aspects: field investigation and customer reputation. Through on-the-spot investigation, we can understand the size and equipment of the machining plant, which is the hardware basis to ensure product quality. The reputation of customers can be obtained from two aspects: one is the enterprise that has cooperated with the machining plant, and the other is the competitor of the machining plant. By summarizing the information given in these two aspects, we can objectively conclude whether the enterprise is reputable and honest. 2. Strength of machining manufacturers This is the most critical aspect besides reputation, which is also echoed by field visits. On the spot investigation can not only understand the reputation of the machinery processing plant, but also intuitively see the strength of the plant. You can see here how the equipment of their factory is, whether it can process the products you need, or whether the equipment of this factory is too advanced to cause high quotation. 3. Business philosophy Strength and reputation are only external factors, which should also be understood from the inside of the machining plant. The company's corporate culture, business philosophy, etc. need to be added to the selection criteria as conditions when understanding the plant. A positive corporate culture and a complete business philosophy are the software foundation of high-quality products. 4. Technical ability of processing team This is also one of the software to ensure product quality, and it is an important software. Because once we cooperate with the machining plant, the most direct contact with the product is the processing team. Only when the processing team is consistent with the ideas and ideas of customers can we produce products that meet the needs of customers. It also reduces a lot of trouble for subsequent communication. In the actual selection process, the demander enterprise should choose an excellent machining plant according to the development of the market and the actual situation. The more famous and larger the machining plant is, the better. The best choice is suitable for its own products.

The definition of difficult to machine materials has been changing with the development of processing technology. At this stage, it mainly refers to titanium alloy, super heat resistant alloy, carbon fiber and other materials. In recent years, the industrial manufacturing industry has greatly increased the requirements for high hardness, high toughness and high wear resistance of parts, and this kind of difficult to machine materials will be encountered more and more. In addition, some new difficult to process materials are constantly appearing in the list of machined materials. When cutting difficult materials, the tool life will be significantly reduced due to the large amount of cutting heat. Therefore, it is necessary to take corresponding technical measures for different cutting methods to improve machining efficiency and prolong tool life. Requirements of cutting tool materials for cutting difficult machining materials In terms of tool materials, cubic boron nitride tools have the best high-temperature hardness among the existing tool materials, and are the first choice for machining difficult materials. In addition, cubic boron nitride sintered body is also a good choice for processing high hardness steel and cast iron materials, and with the increase of cubic boron nitride content, the service life will also increase. At present, CBN sintered body without binder has been developed. Titanium and titanium alloys in difficult to machine materials, due to their high chemical activity and low thermal conductivity, are suitable for cutting with diamond tools with sharp edges and high thermal conductivity. Because the cutting tool of this material has less heat retained at the tip, and its chemical properties are relatively stable, it can prolong the service life of the cutting tool. The diamond sintered tool is also suitable for cutting aluminum alloy, pure copper and other materials. In addition to the above two materials, there is a new type of coated cemented carbide material, which uses ultra-fine grain alloy as the matrix and selects coating materials with good high temperature hardness for coating treatment. By using coatings with different properties, it can be almost suitable for cutting all kinds of difficult to machine materials. With the help of some coating materials with superior performance, this kind of tool has been applied to the field of high-speed machining. Requirements of cutting tool shape for machining difficult materials Let's take a look at the geometry of the tool, which is also a very important determinant, which directly affects the performance of the tool material. This mainly includes the front angle, back angle and cut in angle of the tool, as well as some treatment of the tool tip. In recent years, with the wide promotion and application of high-speed milling technology, small cut depth reverse milling has become the mainstream, which is conducive to reducing the load of cutter teeth and improving the feed speed. In order to adapt to this trend, the design idea of tool cutting edge shape is also undergoing an "evolution". When drilling difficult to machine materials, in order to minimize torque and cutting heat, it is necessary to control the contact area between the cutting surfaces within a minimum range. The means that can be taken is to increase the sharp angle of the drill and carry out cross grinding. The difficulty of chip removal in drilling is a prominent problem. In order to facilitate the discharge of chips, a coolant spray outlet can be set at the back of the bit cutting edge, which is a very effective method to improve the cooling and chip removal effect. Requirements for cutting conditions for machining difficult materials When cutting difficult materials, only very low machining conditions are usually set. However, with the improvement of tool performance and the use of high-speed CNC machine tools and high-speed milling, the cutting conditions of difficult to machine materials have been greatly improved, and even entered the era of high-speed cutting. At present, the requirements of cutting difficult to machine materials for cutting conditions are mainly focused on reducing the load on the cutting edge of the tool and reducing the cutting heat. Using small cutting depth can effectively reduce the cutting edge load of the tool, so as to improve the cutting speed and feed speed; Intermittent cutting can avoid a large amount of cutting heat staying on the cutting edge. For example, in the finishing of holes, the trend of using intermittent cutting method to replace the traditional continuous cutting method is more beneficial to increase the stability of cutting, improve chip removal performance and prolong the tool life. The same processing strategy is also applied to screw hole processing. When rough machining difficult materials with ball end milling cutter, the tool shape and fixture should be well matched, which can improve the swing accuracy and clamping rigidity of the cutting part of the tool, so as to ensure that the feed rate per tooth is maximized under the condition of high-speed rotation, and at the same time, it can also extend the service life of the tool.

Although the price of machining technology does not fluctuate much according to the market, its calculation method will also change according to the addition of external conditions such as different times, regions, national policies and so on. Detailed quotation method of machining process 1. The calculation of process time is required for each key or complex part. 2. Understand the price of working hours in the local market, and calculate the processing cost according to the hourly cost of equipment. For example, for specific equipment, ordinary vertical equipment is between 60-80 yuan, and ordinary equipment such as milling machines and ordinary cars is 30 yuan. 3. After calculating the cost, we should add the packaging and transportation expenses, management expenses, profits, taxes, etc. in a certain proportion, which is the actual price we can quote. However, to a certain extent, the actual price is also closely related to the purchase volume of parts and the size of production batches. The quotation of processing technology has certain flexibility, that is to say, a part may have different quotations, mainly considering that the process arrangement that may be used to process the same part is different, so the cost will also be different. However, sometimes you often encounter a complex process arrangement with a high quotation, and the simple process is used in the actual operation. At this time, the purchaser's ability in parts processing, drawing analysis and so on is required. Therefore, it is also very important to train buyers in machining knowledge. Rough quotation method of machining process If you need to process a workpiece, you should first record the material cost and the travel expenses of purchasing the workpiece. Then determine the working hours required for processing the workpiece according to the processing technology. At present, the price of working hours in the market is 10-15 yuan / hour for fitters and 10-20 yuan / hour for general lathe workers. If the processing is complex and there is no ready-made tools and equipment, the purchase price and need to be recorded separately. In addition, machine depreciation costs, labor costs, management fees, taxes, transportation costs, etc. need to be calculated. Some enterprises will also include business expenses in the quotation, so for the quotation staff, they need to have a deep understanding of the market. If they are not careful, they will reduce their profits due to the lack of one item. The processing cost should also be included in the process problem (the processing cost is different for different processing methods). The main thing is to determine the process, that is, the processing method we call, and then calculate the company according to the process. The basic processing cost of a single part is determined by the working hours, plus other costs. The quotation of machining process is a complex system. For the bidder, every quotation is a challenge. It is not only necessary to make a reasonable quotation according to the specific conditions of processing, but also to maximize the profits of the enterprise. Therefore, there are still many things to learn for the quotation staff of machining.

In machining, different machining steps have different requirements for the use of cutting fluid. When the rough and finish machining of the workpiece are carried out separately, the appropriate cutting fluid can be selected according to the respective characteristics of the rough and finish machining. Rough machining: cooling is the most important During rough machining, the back feed and feed of cutting are usually larger than those of finishing machining, so it will encounter greater cutting resistance and generate more cutting heat, which will aggravate tool wear and workpiece thermal deformation. Therefore, the cutting fluid selected in the rough machining process should mainly focus on its cooling function, and the concentration of cutting fluid is generally lower than that of finish machining. Water based cutting fluid, which is mainly used for cooling and has certain lubrication, cleaning and rust prevention functions, is a good choice. When the milling object is a workpiece with irregular shape and uneven allowance, or the intermittent machining method is adopted, because the cutting speed is lower than continuous uniform machining, the influence of cutting heat is relatively small, and the lubrication and cooling effects can be considered more evenly. Internal liquid supply and spray liquid supply can have a good effect. When rough machining difficult to machine materials and non-ferrous metals, water-based extreme pressure emulsion can be used as machining fluid because of the low requirements for surface roughness and certain machining allowance. Generally, cutting fluid is not used for rough machining of cast iron and brittle non-ferrous metals. Because this material will produce fine chip fragments, which will flow under the impact of cutting fluid. During the flow process, due to deposition, some small cutting fluid transmission pipes will be blocked or adhered to the moving parts of the machine tool. In addition, the chips will also react with cast iron, causing the cutting fluid to deteriorate and reduce the performance of the cutting fluid. Cutting fluid is not used, but the influence of chips and cutting heat cannot be ignored. Dust extraction device can be used to remove chips and heat. Finishing: high speed and low speed are different The most remarkable characteristics of finish machining are high cutting speed and small cutting force. The cutting heat generated by chip deformation is lower than that generated by tool flank friction, and the thermal deformation of workpiece is not very significant. Cutting fluid mainly acts on the flank of the tool. When using cutting fluid for finish machining, sufficient pressure should be provided, because if it cannot penetrate into the cutting area, it will not play its due role. In that way, the tool is prone to wear on the flank, which affects the roughness of the machined surface. Finish machining is divided into high-speed finish machining and low-speed finish machining, which is divided according to the cutting speed of the tool. If oil-based cutting fluid is used in high-speed finishing, oil smoke, oil mist and oil vapor will be produced due to low viscosity and flash point, and some toxic volatiles will be secreted, affecting the health of workers. Therefore, high-speed machining is suitable for using emulsion or microemulsion containing extreme pressure additives in water-based cutting fluid, and the concentration is slightly higher than that of rough machining. When high-speed finish machining non-ferrous metals, emulsions of inactive extreme pressure additives should be selected. In low-speed finishing, because of the low degree of friction and the low heat generated, it is not easy to have the problem of toxic and harmful substances in high-speed finishing. Therefore, it is more important to maintain better lubricity and machining accuracy of the workpiece, and it is more appropriate to use oil-based cutting fluid. When finishing ferrous materials at low speed, active extreme pressure cutting oil should be selected; Inactive extreme pressure cutting oil should be selected when finishing nonferrous metals at low speed

Aluminum is a commonly used metal in industry and life. In the process of aluminum processing, surface treatment is an important link, with various methods and different effects. Sometimes only one method can meet the needs, and sometimes multiple methods are needed to cooperate to meet the requirements of the product. Among them, anodic oxidation is the most widely used method. Next, let's talk about the role of anodizing in aluminum surface treatment. Enhance the corrosion resistance of aluminum products Anodizing can obtain an oxide film on the surface of aluminum products, which has very stable chemical properties and strong corrosion resistance. For example, aluminum materials anodized in chromic acid solution have dense oxide film on the surface and good corrosion resistance, which is particularly suitable for riveted parts and weldments; The aluminum material anodized in sulfuric acid solution has a higher thickness of oxide film and stronger adsorption capacity, but because the pores are larger than the former, it needs to be properly filled and sealed. Improve the adsorption of aluminum products to pigments Anodized aluminum products after chemical or electrochemical polishing will form a transparent oxide film on the surface. Moreover, this oxide film is porous and has good adsorption capacity. It can effectively adsorb a variety of organic or inorganic dyes, as well as paints and organic films. Therefore, try anodizing the aluminum material before painting or coloring, so that the pigment can be better combined with the aluminum material, so that the aluminum products can have a variety of bright colors and increase the appearance of beauty. Not only that, this color film can also play a good anti-corrosion effect. Enhance the wear resistance of aluminum products The oxide film formed by anodic oxidation is not only anti-corrosion, but also very dense. Through hard anodic oxidation of aluminum and aluminum alloy, a layer of aluminum oxide film with large thickness, high hardness and low roughness can be obtained on the surface. And the empty structure will also absorb some lubricating oil. The existence of this oxide film greatly enhances the wear resistance of aluminum products, which can effectively adapt to the friction working state, such as being used as automobile engine cylinder, piston and other parts. Such an oxide film can be obtained by anodic oxidation in sulfuric acid or oxalic acid solution. Realize the electrical insulation of aluminum products The chemical structure of the film obtained by anodic oxidation is metal oxide rather than metal, so it has strong electrical insulation. Some aluminum materials require electrical insulation, such as the dielectric layer of capacitors. This can be achieved by anodic oxidation. As the electroplated bottom layer of aluminum products Before electroplating of aluminum and aluminum alloy products, the bottom layer must be applied first, and then electroplating can be carried out. There are many methods to apply the bottom layer on the surface of aluminum products, including galvanizing, zinc dipping, electroless nickel plating, and of course, anodic oxidation. Due to the porosity of the oxide film obtained by anodic oxidation, it can play a good role in promoting the subsequent electroplating processing effect.

Although technology is the most important for machining manufacturers. Whether it is CNC machine tools, lathes, milling and other specific processing technology, or the quotation, quality evaluation and quality control after processing, we need to have a certain understanding. However, a common phenomenon in the machining industry is that many managers were technical before, and their technical literacy is very strong, but their management ability is relatively poor. In fact, the hook net tells you that the management of machining enterprises also has a certain "routine". For the management of machining enterprises, whether machining industry or other industries, the management methods have certain similarities. The most basic is inseparable from standardization, workflow and formatting, and these three are what we call "routines". 1、 Standardization of management Standardization in the field of modern machinery is the pursuit of many first-class enterprises in management. The first automatic production line of Ford is the standardization of parts. In the field of global economy, standardization is not only the pursuit of an enterprise, but also the pursuit of the whole industry production chain. In the field of machining, standardization is embodied in the specific processes of process standardization, procedure standardization, operation standardization and working terminology standardization. At the same time, human factors are added to the standards to form their own unique core standardization competitiveness. In this way, no matter how modern management evolves, its core is still solid and reliable. 2、 Process management Standard is a point, so the process is a line, and the wisdom of management is to integrate all kinds of effective factors. A very important point in modern management is to skillful the process, which can also be called "play". The process can be a wide range. As an enterprise's strategy, for example, an enterprise sells a business because of shortening the process, and its essence is to do a better job in a more professional market. The process scope can also be very small, that is, to adapt the production chain within the enterprise, outsource some processes to other companies for processing, develop strengths and avoid weaknesses, focus on their own advantages, and better become markets and customers. 3、 Managed formatting Management people all know that efficiency comes from division of labor, and the organization should be organized into a grid, so that people can be reasonably and effectively placed in a grid suitable for themselves. The formatted management concept does not bind a person in a "grid", but gives people rights and space when formulating a "grid", so that people can improve efficiency in a certain range. It is difficult for modern management to be used in the traditional machining industry, but the changes take place bit by bit. As long as we take the first step, the subsequent work will become very smooth. Therefore, as long as you learn the above three points and keep in mind the principle of "how to manage more scientifically and how to manage more humanized", your enterprise will be better.

Generally, CNC machining usually refers to computer numerical control precision machining, numerical control machining lathe, numerical control machining milling machine, numerical control machining boring and milling machine, etc. It is a new processing technology. Its main work is to compile processing programs and convert the original manual work into computer programming. Manual processing certainly requires experience. Working principle of CNC processing: When the numerical control system is activated, the required machining dimensions are programmed into the software and assigned to the corresponding tools and machines, which perform the specified dimensional tasks like robots. In numerical control programming, the code generator in the digital system usually assumes that the mechanism is perfect. Although there is the possibility of error, this possibility is greater when the NC machine is instructed to cut in multiple directions at the same time. The placement of tools in the CNC system consists of a series of input overviews called part programs. Use the numerical control machine tool to input the program through the punch card. In contrast, the program of CNC machine tools is input into the computer through the keypad. NC programming is retained in the computer memory. The code itself is written and edited by the programmer. Therefore, CNC system provides a wider range of computing power. It is important that the CNC system is never static, because the updated prompt can be added to the pre-existing program by modifying the code. Advantages of CNC machining: ① The number of tooling is greatly reduced, and complex tooling is not required for machining parts with complex shapes. To change the shape and size of parts, only need to modify the part processing program, which is suitable for the development and transformation of new products. ② The processing quality is stable, the processing accuracy is high, and the repetition accuracy is high, which meets the requirements of aircraft processing. ③ In the case of multi variety and small batch production, the production efficiency is high, which can reduce the time of production preparation, machine tool adjustment and process inspection, and reduce the cutting time due to the use of cutting volume. ④ It can process complex surfaces that are difficult to be processed by conventional methods, and even some unobservable processing parts.