Skill Development Mandated for CNC Lathe Machinists

Programming skills

1. Processing order of parts: Drill before flattening to prevent shrinkage during drilling. Perform rough turning before fine turning to ensure part accuracy. Process large tolerance areas before small tolerance areas to avoid scratching the smaller areas and prevent part deformation.

 

2. Choose reasonable speed, feed rate and cutting depth according to the hardness of the material. My personal summary is as follows:1. For carbon steel materials, choose high speed, high feed rate and large cutting depth. For example: 1Gr11, choose S1600, F0.2, cutting depth 2mm2. For cemented carbide, choose low speed, low feed rate and small cutting depth. For example: GH4033, choose S800, F0.08, cutting depth 0.5mm3. For titanium alloy, choose low speed, high feed rate and small cutting depth. For example: Ti6, choose S400, F0.2, cutting depth 0.3mm.

 

 

Tool setting skills

Tool setting can be divided into three categories: tool setting, instrument tool setting, and direct tool setting. Most lathes do not have a tool setting instrument, so they are used for direct tool setting. The tool setting techniques described below are direct tool settings.

First, select the center of the right end face of the part as the tool setting point and set it as the zero point. After the machine tool returns to the origin, each tool that needs to be used is set with the center of the right end face of the part as the zero point. When the tool touches the right end face, enter Z0 and click Measure, and the tool compensation value of the tool will automatically record the measured value, indicating that the Z axis tool setting is complete.

For the X tool set, a trial cut is employed. Use the tool to turn the outer circle of the part slightly, measure the outer circle value of the turned part (such as x = 20mm), enter x20, click Measure, and the tool compensation value will automatically record the measured value. At this point, the x-axis is also set. In this tool setting method, even if the machine tool is turned off, the tool setting value will not change after the power is turned back on and restarted. This method can be used for large-scale, long-term production of the same part, eliminating the need to re-set the tool while the lathe is turned off.

 

 

Debugging skills

 

After compiling the program and aligning the tool, it’s important to debug the casting parts through trial cutting. To avoid errors in the program and tool setting that could cause collisions, it’s necessary to first simulate an empty stroke processing, moving the tool to the right in the coordinate system of the machine tool by 2-3 times the total length of the part. Then start the simulation processing. After the simulation is completed, confirm that the program and tool settings are correct before processing the parts. Once the first part is processed, self-check it and confirm its quality before conducting a full inspection. Upon confirmation from the full inspection that the part is qualified, the debugging process is complete.

 

 

Complete the processing of parts

 

After completing the initial trial cutting of the parts, batch production will be carried out. However, the qualification of the first part only guarantees that the entire batch will be qualified. This is because the cutting tool wears differently depending on the processing material. When working with soft materials, the tool wear is minimal, whereas with hard materials, it wears out faster. Therefore, frequent measurement and inspection are necessary during the processing process, and adjustments to the tool compensation value must be made to ensure part qualification.

 

In summary, the basic principle of processing begins with rough processing to remove excess material from the workpiece, followed by fine processing. It is important to prevent vibration during processing to avoid thermal denaturation of the workpiece.

 

Vibration can occur due to various reasons such as excessive load, machine tool and workpiece resonance, lack of machine tool rigidity, or tool passivation. Vibration can be reduced by adjusting the lateral feed rate and processing depth, ensuring proper workpiece clamping, increasing or reducing tool speed to minimize resonance, and assessing the need for tool replacement.

 

In addition, to ensure the safe operation of CNC machine tools and prevent collisions, it’s crucial to avoid the misconception that one needs to physically interact with the machine tool to learn its operation. Machine tool collisions can significantly damage accuracy, especially for machines with weak rigidity. Preventing collisions and mastering anti-collision methods are key to maintaining accuracy and preventing damage, especially for high-precision cnc lathe machining parts.

 

The main reasons for collisions:

 

First, the diameter and length of the tool are entered incorrectly;

Second, the size of the workpiece and other related geometric dimensions are entered incorrectly, and the initial position of the workpiece needs to be correctly positioned. Third, the workpiece coordinate system of the machine tool may be set incorrectly, or the machine tool’s zero point could be reset during the processing process, resulting in changes.

 

Machine tool collisions mainly occur during the rapid movement of the machine tool. Collisions at this time are incredibly harmful and should be completely avoided. Therefore, it is crucial for the operator to pay special attention to the initial stage of the machine tool when executing the program and during tool change. Errors in the program editing, input of incorrect tool diameter and length, and incorrect order of CNC axis’s retraction action at the end of the program can result in collisions.

 

To prevent these collisions, the operator should fully utilize their senses when operating the machine tool. They should observe for abnormal movements, sparks, noise, unusual sounds, vibrations, and burnt smells. If any abnormality is detected, the program should be stopped immediately. The machine tool should only resume operation after the issue is resolved.

 

In summary, mastering the operation skills of CNC machine tools is an incremental process that requires time. It is based on acquiring basic operation of machine tools, mechanical processing knowledge, and programming skills. The operation skills of CNC machine tools are dynamic, requiring the operator to combine imagination and hands-on ability effectively. It is an innovative form of labor.

 

 

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At Anebon, we believe in the values of innovation, excellence, and reliability. These principles are the foundation of our success as a mid-sized business that provides customized CNC components, turning parts, and casting parts for various industries such as non-standard devices, medical, electronics, cnc lathe accessories, and camera lenses. We welcome customers from all over the world to visit our company and work together to create a brighter future.