What does it take to be a CNC master? I think this is an insoluble problem! Because CNC machining involves many aspects, it requires not only a rich theoretical level, but also superb practical experience and practical abilities.
Generally speaking, after earning a CNC degree and entering a factory, it takes at least 6 years to become a qualified CNC technician. There are absolutely no quick tips in this industry! Nowadays, the division of labor in factories is becoming more and more detailed. You should not think that you have mastered a certain skill and that you do not want to progress. Only by constantly pursuing technological progress and excellence can you establish yourself as a master. in the company.
01Must be an excellent craftsman
CNC machining integrates drilling, milling, reaming, tapping and other processes, which requires high technical knowledge from craftsmen. Indeed, when you choose the profession of mechanical cutter, this means that the beginning of your career is difficult and tough. The basic knowledge learned in school is pitiful compared to the needs of the factory. Mechanical processing engineers are experienced engineers to some extent. So they have to spend a lot of time with the workers, working on lathes, milling machines, grinders, machining centers, etc., then they work in the office compiling processes, estimating materials; consumption and calculate calculations.
This way, after 2-3 years of practice, you can become a skilled craftsman. Young people who have just started working should learn from masters with an open mind. Once they can pass on their decades of experience to you, you will save yourself a lot of detours. Since these experiences cannot be learned from books, the choice of process is based on a comprehensive consideration of the capabilities of the equipment and the technical capabilities of the personnel.
After such a long period of study and accumulation, you should reach the following technical levels and requirements:
1) Be familiar with the structure and process characteristics of drilling, milling, boring, grinding and planing machines;
2) Know the properties of transformed materials;
3) Strong basic knowledge of tool theory, proficiency in conventional use of cutting tools, etc.;
4) Be familiar with the company’s process specifications and guidelines and the general requirements that various processes can achieve, process routes of conventional parts, reasonable material consumption and labor hour quotas, etc. . ;
5) Collect a certain amount of information about cutting tools, machine tools and mechanical standards, especially become familiar with the cutting tool systems used in numerical control machine tools;
6) Be familiar with coolant selection and maintenance;
7) Have a common sense understanding of related types of work, such as: foundry, electrical machining, heat treatment, etc.;
8) Have a good lighting base;
9) Understand the assembly and use requirements of parts being processed;
10) Have a good foundation in measurement technology.
02 Proficiency in CNC programming and computer software applications
It’s relatively simple, there are only a few dozen programming instructions, and different systems are similar. It usually takes 1-2 months to get used to it. CAM programming software is a bit more complicated and requires learning to model, but it’s not difficult for people with a good foundation in CAD. Researchers are the most adaptable to 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 goal is to be simple, practical and reliable. From the perspective of understanding instructions from a programming perspective, the main instructions are G00 and G01, and the others are auxiliary instructions, which are configured to facilitate programming;
2) Easy to adjust. When the machining accuracy of parts needs to be fine-tuned, it is best not to modify the program. For example, if the tool is worn and needs adjustment, simply change the length and radius in the tool offset table;
3) Easy to use. Programming should be based on the operating characteristics of the machine tool, conducive to observation, inspection, measurement, safety, etc. For example, the same type of parts and the same processing content are processed separately in a vertical machining center and a horizontal machining center, but the programs are different.
In machining, the simplest way is the best. Anyone with practical experience will probably agree with this!
03Be able to skillfully use CNC machine tools
This requires 1 to 2 years of learning and the operation requires a good feeling. Beginners, especially students, know what to do, but their hands just don’t obey the instructions. In this process, you need to learn: system operation methods, fastener installation, part reference alignment, tool alignment, work offset adjustment, length compensation adjustment tool, radius compensation, loading and unloading of tool and tool holder, as well as tool cutting. Grind and measure workpieces (be able to skillfully use calipers, micrometers, dial gauges, dial gauges, inner diameter lever gauges), etc.
The practice of the operation requires understanding! Sometimes there really is an artistic concept of “taking a leisurely approach to understanding something, but it’s hard to tell you the beauty of it”! In the CNC workshop, calm down and train hard! Generally speaking, the process from processing the first part to qualified processing precision requires CNC programming craftsmen to carry it out in person. If you are not proficient in using machine tools, you will not be able to pass this level.
04Good tooling mounting base and measuring technology level
Here I list tooling equipment and measuring technology separately, because they play as important a role in the quality of workpiece processing as the precision of machine tools and are one of the signs that reflect the level of craftsmen . The whole process system: the precision of the machine tool is guaranteed by the machine tool manufacturer, and the cutting tools and cutting parameters are provided by the tool manufacturer. Usually the problem is not serious. Only tools and accessories are specially designed by. Craftsmen for specific pieces. Most parts of CNC machine tools have a certain degree of difficulty, so unpredictable problems often arise. When cutting and debugging user parts of CNC machine tools, there are very few fixtures that do not need to be modified.
When debugging, more than half of the reasons for the first part processing failure are due to unreasonable positioning, clamping points and clamping force of the fixture. The difficulty in analyzing the causes of impasses is that they can only be qualitative and difficult to quantify. If you have no experience designing fixtures and clamping parts, this will be difficult. To learn in this field, it is recommended to consult technicians who manufacture precision coordinate boring machines.
Accurate level measurement is one of the basic machining skills. You must be able to skillfully use vernier calipers, micrometer cards, dial indicators, dial indicators, inner diameter lever gauges, vernier calipers, etc. Sometimes, when processing parts, one cannot rely on a coordinate measuring machine. Must be measured manually. Imagine, if the parts are not measured accurately, which master would trust you? It takes a lot of time to perfect your measurement skills!
05 Mastery of the maintenance of numerically controlled machine tools
First of all, you must be familiar with CNC machine tools. You must do the following:
1) Familiar with CNC electrical components and control principles. Can know the name and function of each component in the electrical box and understand electrical diagrams. The alarm content can be found according to the electrical alarm number.
2) Understand the structure and transmission principle of the ball screw. Understand which factors have the greatest impact on machine tool accuracy.
3) Understand the structure of bearings at both ends of the machine tool screw and its impact on the precision of the machine tool.
4) Understand the lubrication system of the machine tool (bearings, spindles, kinematic torques, reduction gears, etc.) and know the distribution of each lubrication point. The brand of machine tool lubricating oil and normal weekly or monthly oil consumption.
5) Understand the machine tool refrigeration system: cutting cooling (water, air), spindle cooling, electrical box cooling, etc.
6) Understand the main transmission structure of the machine tool and the specific characteristics of the data between the speed and torque of each machine tool.
7) Understand the characteristics of the machine tool guide rail: is it a linear rail or a slide, and what is its rigidity (load capacity)?
8) Ability to troubleshoot common operating faults (such as exceeding limits, incorrect tool number in tool magazine, etc.)
9) Master various precision indicators (static, dynamic) and detection methods of machine tools.
10) Familiarize yourself with the tool magazine mechanism and the principles of tool changing.
Without more than three years of training, it may be difficult to meet the requirements for the above. In addition, many companies do not yet have the necessary conditions for learning. It is recommended to consult with the masters of the equipment maintenance department.
I will not go into details of machine tool maintenance. Each company has its own experience and standards. Machine tool maintenance focuses on “maintenance”. You should pay attention to (long-term records should be kept):
1) When starting the machine daily, it is important to ensure that the starting load of each axis of the machine tool changes normally. If the starting load changes abnormally, it means the resistance of the kinematic pair or transmission pair. has changed and the machine must be stopped immediately for inspection. Otherwise, over time, it will cause great damage to the machine tool.
2) Pay attention to the normal consumption of lubricating oil. You have to check either too much or not enough.
3) Clean the air conditioner filter and electrical box ventilation filter frequently. Once the integrated circuit board of the power module and drive module inside the electrical box is contaminated with dust containing iron powder, the machine tool will issue an inexplicable alarm and cannot be repaired. Just wait until you change boards!
06 Develop good habits and adapt to the characteristics of CNC machining
A master suitable for CNC machining must be someone humble, rigorous, calm, thoughtful, organized and independent-minded.
1) Processing some large parts not only requires a lot of processing content, but also requires the conversion of three-dimensional coordinates into space. Calculating the machining path is very complex and difficult to determine. If the problem is not examined carefully and comprehensively, the calculation is not accurate, and the more the program is changed during debugging, the more chaotic and likely it will be. errors will be high. “Think before you act” is most appropriate here.
2) The part debugging process is a collaborative process involving multiple people, including operators, inspectors, fixture designers, fixture assembly personnel, etc. When problems arise, seek more feedback, experiment more, and avoid drawing arbitrary conclusions. Don’t blame employees who make too many mistakes and have a “compassionate” attitude.
3) The work of CNC machine tools is controlled by instructions When debugging, you must be very clear about the path 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. This can range from discarded parts to serious safety accidents. Those who have a bad temper, are clueless and refuse to change despite repeated warnings are not suitable for using CNC machine tools.
4) If any problem occurs during debugging and processing, be calm and don’t panic. If a malfunction occurs again, you must have good psychological quality.
5) When parts fail the test multiple times, analysis should be organized and responsibilities should be based on a basis. Some relevant departments will give various explanations for various reasons. At this point you need to assert to yourself: it doesn’t matter if you do something wrong, but you can’t choose the wrong way to do it.
6) The technical capacity of any craftsman will always have limits due to environmental constraints. Along with the rapid development of technology, there is always room for improvement. After all the internal technologies of the factory have been digested, we need to look outside and follow the advanced processing technologies at home and abroad to learn and digest them.
Through this article, you should know that those who do CNC actually have a lot to learn and have a lot to do. It’s not easy for everyone. Everyone has to work hard and work hard to improve themselves.
Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.
