How to learn CNC machining? 6 methods to move forward to the road of CNC engineers!

Table of contents
Step 1: must fully understand the concept of craftsmanship.
Step 2: Familiar with the application of CNC G-CODE and computer software.
Step 3: Be proficient in operating CNC machine tools.
Step 4: There must be a good tooling and fixture foundation and measurement technology level.
Step 5: Familiarize yourself with the CNC machine tool. Proficient in the maintenance of CNC machine tools.
Step 6: Cultivate good habits and adapt to the characteristics of CNC machining.

No matter what line of work, if you want to become a master in the middle school, you must stand the experience of time and constantly improve your work ability. In the CNC processing industry, if you want to become a CNC master (metal processing), you must start from an apprenticeship, and finally It takes at least 1 year. Not only theory, but also practical experience and hands-on ability are needed. Let me share: How to learn CNC machining? 6 methods to move forward to the road of CNC engineers!

Step 1: must fully understand the concept of craftsmanship.

CNC machine tool includes drilling, milling, boring, reaming, tapping and other processes in one. The technical literacy of engineers is very high. CNC program is the process of using G-CODE language to realize the machining process. The concept of craftsmanship is the basis of the program. If you don’t understand the concept of craftsmanship, you can never claim to be able to write programs.

The following technical standards and requirements should be met:

1. Familiar with the structure and process characteristics of drilling, milling, boring, grinding and planing machines,
2. Familiar with the properties of processing materials.
3. Solid theoretical basic knowledge of cutting tools, mastering the conventional cutting amount of cutting tools, etc.
4. Familiar with process specifications, guidelines and general requirements that can be achieved by various processes, and the process route of conventional parts. Reasonable material consumption and working hour quota, etc.
5. Collect a certain amount of information on cutting tools, machine tools, and mechanical standards. In particular, be familiar with the tool system for CNC machine tools.
6. Familiar with the selection and maintenance of coolant.
7. Have a common sense understanding of relevant types of work. For example: casting, electrical machining, heat treatment, etc.
8. Have a good fixture foundation.
9. Understand the assembly requirements and usage requirements of the processed parts.
10. Have a good foundation of measurement technology.

Step 2: Familiar with the application of CNC G-CODE and computer software.

I think this is relatively easy, there are only dozens of programming instructions, and various systems are similar. It usually takes 1-2 months to be very familiar with it. The automatic programming software is a little more complicated, and it is necessary to learn CAD/CAM. But for people with good CAD foundation, it is not difficult. In addition, if programming by hand, the basics of analytic geometry are also good!

The criteria for a good program are:

1. Easy to understand and organized.
2. The fewer instructions in a block, the better.
   To be simple, practical and reliable. From the perspective of programming, I think that the commands are G00 and G01, and the others are auxiliary commands, which are set for the convenience of programming.
3. 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.
4. Easy to operate.
   Program editing should be edited according to the operating characteristics of the machine tool.
   Design and processing, which is conducive to observation, inspection, measurement, safety, etc. For example, the same part and the same processing content are processed separately in a vertical machining center and a horizontal machining center, and the programs are definitely different.

Step 3: Be proficient in operating CNC machine tools.

The operation is about feel, beginners know what to do, but they just don’t know how to start. In this process, you need to learn: system operation, fixture installation, part datum alignment, tool setting, setting zero offset, setting tool length compensation, radius compensation, loading and unloading of tool and tool holder, tool edge Grinding, measurement of parts (skilled in using vernier calipers, microcards, dial indicators, dial indicators, inner diameter lever tables), etc.

Generally speaking, the process from the machining of the first part to the qualified machining accuracy requires the engineer who writes the CNC program to complete it himself. If you can’t operate the machine tool proficiently, you can’t pass this level.

Step 4: There must be a good tooling and fixture foundation and measurement technology level.

I list the fixture and measurement technology separately because: it plays an important role in the quality of parts processing as well as the precision of the machine tool, and it is one of the signs that reflects the level of the craftsman. The whole process system: the precision 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 fixture is specially designed by the craftsman for specific parts. Parts are difficult, so unforeseen problems often occur.

During debugging, the first part is not qualified, and more than half of the reasons are due to the unreasonable positioning, clamping pressure point and clamping force of the fixture. The difficulty of the analysis of the fixture is that it can only be qualitative and difficult to quantify. If there is no experience in fixture design and part clamping, it will be difficult. In this aspect of learning, it is recommended to consult senior technicians who do precision coordinate boring machines. When accurately measuring the level, one of the basic skills of machining is to be proficient in using vernier calipers, micro cards, dial indicators, dial indicators, inner diameter lever meters, calipers, etc. Sometimes parts processing, CMM can not be counted on. Must be measured by hand.

It can take a long time to develop a good measurement technique!

Step 5: Familiarize yourself with the CNC machine tool. Proficient in the maintenance of CNC machine tools.

The so-called familiar with CNC machine tools, should do:

1. Familiar with numerical control electrical components and control principles. Can tell the names and functions of various components in the electric box, and 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 the machine tool.
3. Understand the structure of the bearings at both ends of the machine tool screw and its influence on the precision of the machine tool.
4. Understand the lubrication system of the machine tool (bearings, spindles, motion pairs, gearboxes, etc.), and know the distribution of lubrication points. The grade of machine tool lubricating oil and the normal consumption of oil per week or month.
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 the machine tool guide rail: is it a linear rail or a slide rail, and what is the rigidity (bearing capacity)?
8. Can eliminate common operation failures (such as: exceeding the limit, tool magazine tool number error, etc.)
9. Proficient in various precision (static, dynamic) indicators and detection methods of machine tools.
10. Familiar with the tool magazine mechanism and the principle of tool change.

The above items do not have more than 3 years of time to exercise, I am afraid it is difficult to meet the requirements. And many companies do not have the conditions to learn. It is recommended to consult the master of the equipment maintenance department for advice.

I won’t talk about the maintenance details of the machine tool. 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 start the machine every day and pay attention to whether the starting load changes of each axis of the machine tool are normal. If the change is not normal, it means that the resistance of the motion pair or transmission pair has changed, and it is necessary to stop the machine immediately for inspection. Otherwise, over a long period of 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 screen of the electric box and the air vent filter screen frequently. Once the integrated circuit board of the power module and drive module inside the electric box is stained with dust containing iron powder, the tool will give an inexplicable alarm.

Step 6: Cultivate good habits and adapt to the characteristics of CNC machining.

The masters who are suitable for CNC machining should be humble, rigorous, calm, thoughtful, organized and assertive.

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 machining trajectory is very complex and difficult to determine. If the consideration of the problem is not detailed and comprehensive, the calculation is not accurate, and the program modification becomes more and more chaotic during debugging, and the probability of error is high. “Think before you act” is most appropriate here.
2. The part debugging process is a process of multi-person cooperation, including operators, inspectors, fixture design, fixture assembly personnel, etc.
3. The work of the CNC machine tool is controlled by instructions. When debugging, before pressing the “Start” button, you must be very clear about the running track of the machine tool. 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. From scrapped parts, to serious safety accidents.
4. If there is a problem during debugging and processing, be calm and do not panic, and then there is a wrong operation. Mental quality is better.
5. When the parts are unqualified many times during debugging, the analysis must be organized and the responsibility given must be based. Some relevant departments will give various explanations for various reasons. At this time, you must have your own opinion and remember: it doesn’t matter if you do one thing wrong, but you can’t choose the wrong way to do things.
6. An engineer, limited by the environment, always has limited technical ability. Coupled with the rapid development of technology, there is always room for improvement. When the internal technology of the factory has been digested, we must look outside, closely follow the advanced processing technology at home and abroad, learn and digest.

I am a CNC lathe engineer in Rongtai, the company is located in Taichung, Taiwan – sharing with you

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