CNC engraving machining knowledge decryption

1. What is the main difference between CNC engraving and CNC milling?

CNC engraving machining and CNC milling machining have adopted the milling processing principle. The main difference is in the diameter of the tool used, of which the commonly used tool diameter range of CNC milling is 6-40 mm, while the tool diameter of CNC engraving is 0.2-3 mm.

2. CNC milling can only do rough machining, CNC engraving can only do fine machining?

Before we can answer this question, let's first understand the concept of the process. The processing amount of roughing process is large, and the processing amount of finishing is small, so some people habitually consider roughing as "heavy cutting" and finishing as "light cutting". In fact, roughing, semi-finishing and finishing are process concepts, which represent different processing stages. Therefore, the accurate answer to this question is that CNC milling can do heavy cutting, but also can do light cutting, and CNC engraving can only do light cutting.

3. Can CNC engraving processing do rough processing of steel materials?

Judging whether CNC engraving processing can process a certain material, mainly depends on how much tool can be used. The tool used in CNC engraving processing determines its maximum cutting capacity. If the mold shape allows the use of a tool with a diameter of more than 6 mm, it is strongly recommended to first use CNC milling, and then use the engraving method to remove the remaining material.

4. Can the spindle of CNC machining center increase a speed head to complete the engraving processing?

Can't finish. This product appeared at the exhibition 2 years ago, but it was unable to complete the engraving process. The main reason is that the design of the CNC machining center considers its own tool range, and the overall structure is not suitable for engraving processing. The main reason for this wrong idea is that they mistook the high-speed motorized spindle as the only feature of the engraving machine.

5. CNC engraving can use a small diameter tool, can it replace EDM?

Can't be replaced. Although engraving reduces the diameter range of the milling tool, small molds that were previously only available for electrical spark machining can now be achieved with engraving machining. However, the length/diameter ratio of the engraving tool is generally about 5:1. When using a small diameter tool, only a very shallow cavity can be processed, and the EDM process has almost no cutting force, as long as the electrode can be manufactured, the cavity can be processed.

6. What are the main factors affecting engraving processing?

Machining is a more complex process, there are more factors affecting it, mainly the following points: machine tool characteristics, tools, control systems, material characteristics, processing technology, auxiliary fixture and the surrounding environment.

7. What are the requirements for the control system of CNC engraving processing?

CNC engraving machining is first milling, so the control system must have the control ability of milling. For small tool processing, the feedforward function must be provided at the same time, the path speed is reduced in advance, and the cutting frequency of the small tool is reduced. At the same time, it is necessary to improve the cutting speed in the smooth path segment, so as to improve the efficiency of engraving processing.

8. What characteristics of the material will affect the processing?

The main factors that affect the performance of material engraving are material category, hardness and toughness. The materials category includes metallic materials and non-metallic materials. In general, the greater the hardness, the worse the machinability, the greater the viscosity, the worse the machinability. The more impurities, the worse the machinability, the greater the hardness of the particles inside the material, the worse the machinability. A general standard is: the higher the carbon content, the worse the machinability, the higher the alloy content, the worse the machinability, the higher the non-metallic element content, the better the machinability (but the non-metallic content in general materials is strictly controlled).

9. Which materials are suitable for engraving processing?

Non-metallic materials suitable for carving include plexiglass, resin, wood, etc., non-metallic materials not suitable for carving include natural marble, glass, etc. Metal materials suitable for engraving include copper, aluminum, soft steel with hardness less than HRC40, and metal materials not suitable for engraving include hardened steel.

10. What impact does the tool itself have on the processing and how?

The tool factors that affect engraving processing include tool material, geometric parameters and grinding technology. The tool material used for engraving processing is cemented carbide material, which is a powder alloy, and the main performance index that determines the material performance is the average diameter of the powder. The smaller the diameter, the more wear-resistant the tool, the higher the durability of the tool, the more CNC programming knowledge pay attention to the wechat public number (CNC programming teaching) to get the tutorial, the sharpness of the tool mainly affects the cutting force. The sharper the tool, the smaller the cutting force, the smoother the processing, the higher the surface quality, but the lower the durability of the tool. Therefore, different sharpness should be selected when processing different materials. When processing relatively soft and sticky materials, the tool needs to be sharp, and when the hardness of the processing material is large, it is necessary to reduce the sharpness and improve the durability of the tool. However, it can not be too blunt, otherwise the cutting force is too large, affecting the processing. The key factor of grinding tool is the number of mesh of grinding wheel. High mesh grinding wheel can grind a finer cutting edge, which can effectively improve the durability of the tool. A wheel with a high mesh can produce a smoother back tool surface, which can improve the surface quality of the cutting.

11. What is the tool life formula?

The 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, P is the depth of the cutting tool). The most important factor affecting tool life is the cutting line speed. In addition, the radial runout of the tool, the grinding quality of the tool, the tool material and coating, and the coolant will also affect the durability of the tool.

12. In the process of processing, how to protect the engraving machine equipment?

1) Protect the tool, do not let it be too much oil erosion.

2) Pay attention to the control of flying chips, flying chips are very harmful to the machine tool, flying into the electric control cabinet will lead to short circuit, flying into the guide rail will reduce the life of the lead screw and guide rail, so in the processing, the main part of the machine tool should be sealed.

3) When moving the lamp, do not pull the lamp holder, so it is easy to pull the lamp holder.

4) In the processing process, do not close to the cutting area for observation, so as to avoid flying debris injury to the eyes. When the spindle motor is rotating, do not perform any operation on the table surface.

5) In the opening and closing of the machine door, do not fiercely open and close, in the finishing process, the impact vibration of the opening process will lead to the surface of the processed knife.

6) To give the spindle speed, after the start of processing, otherwise due to the slow rotation of the spindle, resulting in the start of processing without reaching the desired speed, so that the motor suffocates.

7) It is forbidden to place any tool or workpiece on the beam of the machine tool.

8) It is strictly prohibited to place magnetic tools such as magnetic suction cups and dial indicator seats on the electric control cabinet, otherwise the display will be damaged.

13. There is a phenomenon of holding in the machining process of the new knife, and the processing is very laborious. What parameters need to be adjusted at this time?

The reason why the processing is very laborious is that the power and torque of the spindle can not withstand the current cutting amount, and the reasonable way is to re-make the path to reduce the depth of the cutting tool, 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.

14. What is the role of cutting fluid?

Metal processing pay attention to add cooling oil. The role of the cooling system is to take away the cutting heat and flying chips, and play a lubricating role in the processing. The coolant will move the cutting wire, reducing the heat transferred to the tool and motor and increasing their service life. Take away the flying chips to avoid the phenomenon of secondary cutting. Lubrication can reduce the cutting force and make the process more stable. In copper processing, the selection of oily cutting fluid can improve the surface quality.

15. What are the stages of tool wear?