How to be a CNC master? I believe this is an unsolvable problem! Because CNC machining involves many aspects, it must not only have a rich theoretical level, but also have superb practical experience and hands-on ability.
Generally speaking, after graduating from a CNC major and entering a factory, it takes at least 6 years to create a qualified CNC technician. There is absolutely no quick-start skill in this industry! Now that the division of labor in the factory is becoming more and more detailed, you must not think that you have mastered a certain skill and do not think about making progress. Only by constantly pursuing technological progress and continuous pursuit of excellence can you gain a foothold in the enterprise as a master.
01
Must be an excellent craftsman
CNC machining integrates drilling, milling, boring, reaming, tapping and other processes, which requires high technical literacy of craftsmen. In fact, when we choose the profession of mechanical cutting, it means that the early stage of employment is hard and rough. A little basic knowledge learned in school is pitifully small in the face of the needs in the factory. Mechanical processing engineers are, to some extent, experienced engineers. Therefore, a lot of time must be spent with workers, working on lathes, milling machines, grinding machines, machining centers, etc.; Forehead.
In this way, after 2-3 years of practice, you can basically become a qualified craftsman. Young people who are new to work must be open-minded to learn from the master workers. Once they can pass on decades of experience to you, you can avoid many detours. Because these experiences cannot be learned from books, the choice of process is a choice that comprehensively considers equipment capabilities and personnel technical capabilities.
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After such a long period of study and accumulation, you should meet the following technical standards and requirements:
1) Familiar with the structure and process characteristics of drilling, milling, boring, grinding and planing machines;
2) Familiar with the properties of processed materials;
3) Solid theoretical basic knowledge of cutting tools, master the conventional cutting amount of cutting tools, etc.;
4) Familiar with the company's process specifications, guidelines and general requirements that can be achieved by various processes, the process route of conventional parts, reasonable material consumption and working hours quota, etc.;
5) Collect a certain amount of information on cutting tools, machine tools, and mechanical standards, especially familiar with the tool system used in CNC machine tools;
6) Familiar with the selection and maintenance of coolant;
7) Have a common-sense understanding of related types of work, such as: casting, electrical processing, heat treatment, etc.;
8) Have a good fixture foundation;
9) Understand the assembly requirements and use requirements of the processed parts;
10) Have a good measurement technology foundation.
02
Proficient in CNC programming and computer software application
This point is relatively easy, and there are only dozens of programming instructions. The various systems are similar, and it usually takes 1-2 months to become very familiar with them. CAM programming software is a bit more complicated and requires learning modeling, but it is not difficult for people with good CAD foundation. Scholars are most suitable for learning this knowledge.
In practice, the criteria for a good program are:
1) Easy to understand and organized. The fewer instructions in a program segment, the better. The purpose is to be simple, practical and reliable. From the perspective of programming, the main commands are G00 and G01, and the others are auxiliary commands, which are set for the convenience of programming;
2) Easy to adjust. It is best not to change the program when the machining accuracy of the parts needs to be fine-tuned. For example, if the tool is worn out, to adjust it, just change the length and radius in the tool offset table;
3) Easy to operate. The programming should be compiled according to the operating characteristics of the machine tool, which is conducive to observation, inspection, measurement, safety, etc. For example, the same part and the same processing content are processed separately in the vertical machining center and the horizontal machining center, and the procedures are different.
In machining, the easiest way is the best way. As long as you have practical experience in the industry, you must agree with this sentence!
03
Proficiency in operating CNC machine tools
This requires 1-2 years of study, and the operation is all about the feel. Beginners, especially students, know how to do it in their hearts, but their hands just don't listen to them. In this process, you should learn: the operation mode of the system, the installation of the fixture, the alignment of the part datum, the tool setting, the setting of the zero offset, the setting of the tool length compensation, the radius compensation, the installation and removal of the tool and the tool handle, and the blade of the tool. Grinding, measurement of parts (can skillfully use vernier calipers, dial gauges, dial indicators, dial gauges, inner diameter lever gauges), etc.
The practice of operation requires understanding! Sometimes there is really a kind of artistic conception of "leisurely knowing, the beauty is hard to tell you"! In the CNC workshop, you can calm down and practice hard! Generally speaking, the process from the processing of the first part to the qualified processing accuracy is required to be completed by the NC programming technician. If you can't operate the machine tool proficiently, you can't pass this level.
04
Good fixture foundation and measurement technology level
The reason why I list tooling fixture and measurement technology separately is that it plays an equally important role in the processing quality of parts as the precision of machine tools, and is one of the symbols reflecting the level of craftsmen. The entire process system: the accuracy of the machine tool is guaranteed by the machine tool manufacturer, and the tools and cutting parameters are provided by the tool manufacturer. Generally, there are no major problems. Only the tooling and fixtures are specially designed by the craftsman for specific parts. Generally, the parts on the CNC machine tool are There is a certain degree of difficulty, so there are often unpredictable problems. Engaged in the cutting and debugging of parts for CNC machine tool users, there are very few fixtures that do not need to be rectified.
During debugging, the processing of the first part was unqualified, and more than half of the reasons were due to the unreasonable positioning, clamping point and clamping force of the fixture. The difficulty of analyzing the cause of the fixture is that it can only be qualitative, and it is difficult to quantify. If you have no experience in fixture design and parts clamping, it will be very difficult. For learning in this area, it is recommended to consult the technicians who make precision coordinate boring machines.
Accurate measurement level is one of the basic skills in machining. It is necessary to be able to skillfully use vernier calipers, dial gauges, dial indicators, dial gauges, inner diameter lever gauges, calipers, etc. Sometimes parts processing, coordinate measuring machine is not expected. Must be measured by hand. Just imagine, if the parts are not measured accurately, which master will trust you? It takes a long time to get good at measuring!
05
Proficient in the maintenance of CNC machine tools
First of all, you must be familiar with CNC machine tools, and you should do:
1) Familiar with CNC electrical components and control principles. Can tell the name and function of each component in the electric box, and can understand the electrical schematic diagram. According to the electrical alarm number, the alarm content can be found out.
2) Understand the structure and transmission principle of the ball screw. Know which factors have a greater impact on the accuracy of machine tools.
3) Understand the structure of the bearings at both ends of the screw rod of the machine tool and its influence on the accuracy of the machine tool.
4) Understand the lubrication system of the machine tool (bearings, spindles, each kinematic pair, gearbox, etc.), and know the distribution of each lubrication point. The brand of machine tool lubricating oil and the normal weekly or monthly oil consumption.
5) Understand the cooling system of the machine tool: cutting (water, air) cooling, spindle cooling, electric box cooling, etc.
6) Understand the main transmission structure of the machine tool, and the specific data characteristics between the speed and torque of each machine tool.
7) Understand the characteristics of machine tool guide rails: is it a line rail or a slide rail, and what is the rigidity (carrying capacity)?
8) Can eliminate common operation failures (such as: over limit, error in tool magazine tool number, etc.)
9) Proficient in various accuracy (static, dynamic) indicators and detection methods of machine tools.
10) Familiar with the mechanism of tool magazine and the principle of tool change.
It is difficult to meet the above requirements without more than 3 years of exercise. And many companies do not have the conditions to learn. It is recommended to ask the masters in the equipment maintenance department for advice.
I won't go into details about the maintenance of machine tools. Each company has its own experience and standards. The key point of machine tool maintenance is "maintenance", which should be paid attention to at ordinary times (long-term records should be made):
1) It is very important to pay attention to whether the starting load changes of each axis of the machine tool are normal when starting up the machine every day. If the starting load changes abnormally, it means that the resistance of the kinematic pair or the transmission pair has changed, and it is necessary to stop the machine immediately for inspection. Otherwise, over time, the damage to the machine tool will be great.
2) Pay attention to the normal consumption of lubricating oil. Too much or too little must be checked.
3) Clean the air conditioner filter and air vent filter of the electrical box frequently. Once the integrated circuit board of the power module and driver module inside the electric box is stained with dust containing iron powder, the machine tool will give an inexplicable alarm, and it cannot be repaired. Just wait for the board!
06
Cultivate good habits and adapt to the characteristics of CNC machining
A master who is suitable for CNC machining should be a person who is humble, rigorous, calm, thoughtful, organized and independent.
1) The processing of some large parts not only has a lot of processing content, but also the transformation of three-dimensional coordinates in space. The calculation of the processing trajectory is very complicated and difficult to determine. If the problem is not considered carefully and comprehensively, the calculation is not accurate, and the program modification becomes more chaotic during debugging, and the probability of error is high. "Think twice before acting" is most appropriate here.
2) The part debugging process is a process of multi-person cooperation, including operators, inspectors, fixture designers, fixture assemblers, etc. When problems arise, we should seek their opinions more, do more experiments, and avoid making arbitrary conclusions. Don't blame the employees who made mistakes too much, but have a "compassionate" mentality.
3) The work of CNC machine tools is controlled by instructions. When debugging, you must be very clear about the trajectory of the machine tool before pressing the "Start" button. Be rigorous and meticulous, and never let the machine tool move first. Once the program is wrong or the compensation parameters are incorrect, or the wrong coordinate system is selected. Ranging from scrap parts, serious accidents occur. Those who have a rough temper, have no clue in doing things, and refuse to change after repeated admonition are not suitable for the operation of CNC machine tools.
4) If there is a problem during debugging and processing, you must be calm, and you must not panic. If there is another misoperation, you must have a good psychological quality.
5) When a part fails to pass the test many times, the analysis must be organized and the responsibility must be based on a basis. Some relevant departments will give various explanations for various reasons. At this time, you have to be assertive. Remember: it doesn’t matter if you do one thing wrong, but you can’t choose the wrong way to do things.
6) For any craftsman, due to the limitation of the environment, the technical ability is always limited. Coupled with the rapid development of technology, there is always room for improvement. When the internal technology of the factory has been digested, it is necessary to look outside and keep up with the advanced processing technology at home and abroad to learn and digest.
Through this article, you should know that you need to learn so much and do so much to do CNC. Everyone is not easy, and everyone needs to work hard on their own, and only by working hard on their own can they be able to improve.
