Ten questions and answers on CNC engraving hand processing
Date: 2022-08-12
Read: 193
Ten questions and answers on CNC engraving hand processing

1. What is the function of cutting fluid?
Pay attention to adding cooling oil in metal processing. The function of the cooling system is to take away the cutting heat and flying chips and lubricate the machining. Coolant removes the cutting heat, reducing heat transfer to the tool and motor, increasing their service life. Take the flying chips away to avoid the phenomenon of secondary cutting. Lubrication can reduce cutting forces and make machining more stable. In copper processing, the selection of oily cutting fluid can improve the surface quality.

2. How to protect the engraving machine equipment during the processing?
1) Protect the tool setter from excessive oil erosion.
2) Pay attention to the control of flying chips. Flying chips is very harmful to the machine tool. Flying into the electric control cabinet will cause a short circuit. Flying into the guide rail will reduce the life of the lead screw and guide rail. Therefore, during processing, the machine tool should be The main part is sealed well.
3) When moving the lamp, do not pull the lamp head, it is easy to break the lamp head.
4) During processing, do not observe near the cutting area to avoid flying chips from hurting your eyes. Do not perform any operations on the work surface when the spindle motor is rotating.
5) When opening and closing the door of the machine tool, do not open and close it violently. During finishing, the impact and vibration during the opening process will cause the machined surface to have knife lines.
6) Give the spindle speed, and then start processing. Otherwise, because the spindle starts to rotate slowly, the processing will start before the desired speed is reached, which will cause the motor to suffocate.
7) It is forbidden to place any tools or workpieces on the beam of the machine tool.
8) It is strictly forbidden to place magnetic tools such as magnetic suction cups and dial indicator holders on the electric control cabinet, otherwise the display will be damaged.

3. What is the tool life formula?
Tool life is mainly the tool life during the processing of steel materials. The empirical formula is: (T is the tool life, CT is the life parameter, VC is the cutting line speed, f is the amount of cutting tool per revolution per red, and P is the cutting depth). Among them, the cutting line speed is the biggest influence on tool life. In addition, tool runout, tool grinding quality, tool material and coating, and coolant also affect tool durability.

4. What are the stages of tool wear?
The wear of the tool is divided into three stages: initial wear, normal wear, and sharp wear. In the initial wear stage, the main cause of tool wear is that the temperature of the tool is low and does not reach the optimal cutting temperature. At this time, the wear of the tool is mainly abrasive wear, which has a greater impact on the tool. More CNC programming knowledge Pay attention to the WeChat public account (NC programming teaching) to receive the tutorial, which can easily lead to tool breakage. This stage is a very dangerous stage. If it is not handled properly, it may directly lead to tool breakage and failure. When the tool passes the initial wear period, the cutting temperature of the tool reaches a certain value, which is the main wear is diffusion wear, and its role is mainly to cause local spalling. Therefore, the wear is relatively small and relatively slow. When the wear reaches a certain level, the tool fails and enters a period of rapid wear.

5. When the roughing condition is not good, how to adjust the machining parameters?
If the tool life is still not guaranteed at a reasonable spindle speed, when adjusting the parameters, adjust the depth of the knife first, then adjust the feed speed, and then adjust the lateral feed. (Note: There is also a limit to adjusting the cutting depth. If the cutting depth is too small, there will be too many layers, and although the theoretical cutting efficiency is high, the actual processing efficiency is affected by other factors, resulting in too low processing efficiency. At this time, a smaller tool should be used for processing, but the processing efficiency is higher. Generally speaking, the minimum depth of the knife cannot be less than 0.1mm.

6. How to judge severe tool wear?
The method for judging severe tool wear is:
1) Listening to the processing sound, there is a harsh cry;
2) Listening to the sound of the main shaft, the main shaft has obvious stagnation phenomenon;
3) It feels that the vibration increases during processing, and the machine tool spindle has obvious vibration;
4) Looking at the processing effect, the processed knife pattern on the bottom surface is sometimes good or bad (if it is like this at the beginning, it means that the depth of the knife is too deep).
13. During the machining process of the new tool, the turning phenomenon occurs, and the machining is very laborious. What parameters need to be adjusted at this time?
The reason for the laborious processing is that the power and torque of the spindle cannot withstand the current cutting amount. The reasonable approach is to re-make the path and reduce the depth of the knife, the depth of the slot, and the amount of trimming. If the overall processing time is less than 30 minutes, the cutting state can also be improved by adjusting the cutting speed.

7. Can a heavily worn tool continue machining?
After severe tool wear, the cutting force can be increased to 3 times normal. The cutting force has a great influence on the service life of the spindle electrode. The service life of the spindle motor and the force are inversely proportional to the third power. For example, when the cutting force is increased by 3 times, machining for 10 minutes is equivalent to using the spindle for 10*33=270 minutes under normal conditions.

8. When should the tool be changed?
We should change the tool around 2/3 of the tool life limit. For example, if the tool is severely worn in 60 minutes, in the next machining, you should start changing the tool at 40 minutes, and develop the habit of changing the tool regularly.

9. How do you determine how long the tool will stick out during roughing?
The shorter the extension of the tool, the better. However, in actual processing, if it is too short, the length of the tool should be adjusted frequently, which will greatly affect the processing efficiency. So how to control the protruding length of the tool in actual processing? The principle is this: a 3-diameter shank can be processed normally with a 5mm extension. The φ4 diameter shank extends 7mm and can be processed normally. The φ6 diameter shank extends 10mm and can be processed normally. Try to get below these values when you apply the knife. If the length of the upper knife is greater than the above value, try to control the depth of processing when the tool is worn. This is a bit difficult to grasp and requires more exercise.

10. How to deal with the sudden broken tool during processing?
1) Stop processing and check the current serial number of processing.
2) Check the broken tool to see if there is a broken tool body, and if so, take it out.
3) Analyze the reasons for the broken tool, this is the most important, why is the tool broken? If we want to analyze, we need to analyze the various factors that affect the processing mentioned above. But the reason for the broken knife is that the force on the knife suddenly increased. Either the path is wrong, or the tool shakes too much, or the material has a hard block, or the spindle motor does not rotate at the correct speed.
4) After analysis, replace the tool for processing. If the path is not replaced, the original serial number should be processed by a serial number in advance. At this time, it is necessary to pay attention to reducing the feed speed. One is that the broken tool is hardened seriously, and the other is that the tool must be run-in.


+86 13682610409
Whatsapp same number

Welcome to consult

Looking forward to your consultation