1. What are the main differences between CNC engraving and CNC milling?

Both CNC engraving and CNC milling use the principle of milling. The main difference is in the tool diameter used, where the common tool diameter for CNC milling is 6-40 mm, while the CNC engraving tool diameter is 0.2-3 mm.

2. Is CNC milling only for roughing, and CNC machining can only be used for finishing?

Before answering this question, we first understand the concept of the process. The rough machining process has a large amount of machining, and the machining volume of the finishing process is small. Therefore, it is customary to consider rough machining as "heavy cutting" and finishing processing as "light cutting". In fact, roughing, semi-finishing, and finishing are process concepts that represent different stages of processing. Therefore, the exact answer to this question is that CNC milling can be used for heavy cutting or light cutting, while CNC engraving can only be done with light cutting.

3. Can CNC engraving work for rough machining of steel materials?

Judging whether CNC engraving can process a certain material depends mainly on how large the tool can be used. The tool used in CNC engraving determines its maximum resilience. If the shape of the mold allows the use of tools with a diameter of more than 6 mm, it is highly recommended to use CNC milling and then engrave the remaining material.

4. Does the spindle of the CNC machining center add a speed-increasing head to complete the engraving process?

can not be done. This product appeared at the exhibition two years ago, but it could not be finished. The main reason is that the CNC machining center is designed with its own tool range in mind and the overall structure is not suitable for engraving. The main reason for this erroneous idea was that they mistakenly used the high-speed electric spindle as the only feature of the engraving machine.

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

Can't be replaced. Although the engraving process reduces the range of tool diameters for milling, small molds that previously could only be machined by EDM can now be achieved with engraving. However, the length/diameter ratio of the engraving tool is generally around 5:1. When using a small-diameter tool, only a very shallow cavity can be machined, and there is almost no cutting force in the EDM process, and the cavity can be machined as long as the electrode can be fabricated.

6. What are the main factors affecting engraving?

Machining is a relatively complicated process, and there are many factors affecting it. The main points are: machine characteristics, tools, control systems, material properties, machining processes, auxiliary fixtures and surrounding environment.

7. What are the requirements for CNC system for control system?

CNC engraving is first and foremost milled, so the control system must have the control of milling. For small tool machining, the feedforward function must be provided at the same time, the path is decelerated early, and the cutting speed of the small tool is reduced. At the same time, it is necessary to increase the speed of the path in the relatively smooth path segment, thereby improving the efficiency of engraving processing.

8. What characteristics of the material affect processing?

The main factors affecting the engraving performance of materials are material type, hardness and toughness. Material categories include metallic materials and non-metallic materials. In general, the greater the hardness, the worse the processability, the greater the viscosity, and the worse the processability. The more impurities, the worse the processability, and the greater the hardness of the particles inside the material, the worse the processability. A general standard is: the higher the carbon content, the worse the processability, the higher the alloy content, the worse the processability, the higher the non-metallic element content, the better the processability (but the non-metal content in the general material is strictly controlled). of).

9. Which materials are suitable for engraving?

Non-metallic materials suitable for engraving include plexiglass, resin, wood, etc. Non-metallic materials that are not suitable for engraving include natural marble, glass, and the like. Suitable metal materials for engraving include copper and aluminum, soft steel with hardness less than HRC40, and metal materials not suitable for engraving including hardened steel.

10. How does the tool itself affect machining and how does it affect it?

Tool factors that affect engraving include tool materials, geometric parameters, and grinding techniques. The tool material used for engraving is a hard alloy material, which is a powder alloy. The main performance index determining the material properties is the average diameter of the powder. The smaller the diameter, the more wear-resistant the tool and the higher the durability of the tool. The sharpness of the tool mainly affects the cutting force. The sharper the tool, the smaller the cutting force, the smoother the machining, the higher the surface quality, but the lower the durability of the tool. Therefore, different sharpness should be chosen when processing different materials. When processing soft and sticky materials, the tool needs to be sharper. When the hardness of the processed material is large, the sharpness should be reduced and the durability of the tool should be improved. But it should not be too blunt, otherwise the cutting force will be too large, affecting the processing. The key factor in the grinding of the tool is the number of finished grinding wheels. The high-order grinding wheel can grind a more delicate cutting edge, which can effectively improve the durability of the tool. Grinding wheels with a high mesh number can grind a smoother flank and improve the surface quality of the cut.

11. What is the tool life formula?

Tool life is primarily 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 knife per revolution, and P is the depth of the knife). Among them, the maximum cutting tool life is the cutting line speed. In addition, tool radial runout, tool grinding quality, tool material and coating, and coolant can also affect tool durability.

12. How to protect the engraving machine equipment during the machining process?

1) Protect the knife setter and do not let it be excessively eroded by oil.
2) Pay attention to the control of flying debris. The flying debris is very harmful to the machine tool. Flying into the electric control cabinet will cause short circuit. Flying into the guide rail will reduce the life of the lead screw and the guide rail. Therefore, when machining, the machine tool should be used. The main part is sealed.
3) When moving the light, do not pull the lamp, so it is easy to pull the lamp.
4) During the processing, do not observe near the cutting area to avoid flying debris to the eyes. When the spindle motor is rotating, it is forbidden to perform any operation on the work surface.
5) When switching the machine door, do not open the slamming. During the finishing process, the impact vibration during the opening process will result in the surface of the machine being machined.
6) It is necessary to give the spindle speed, and then start the machining. Otherwise, the spindle will rotate slowly, and the machining will start when the desired speed is not reached, causing the motor to die.
7) It is forbidden to place any tools or workpieces on the beam of the machine.
8) It is strictly forbidden to place magnetic tools such as magnetic suction cups and dial gauges on the electric control cabinet, otherwise the display will be damaged.

13. The phenomenon of tumbling during the processing of new knives is very laborious. What parameters need to be adjusted?

The reason why the processing is very laborious is that the power and torque of the spindle cannot withstand the current cutting amount. It is reasonable to re-route, reduce the depth of the knife, the depth of the groove, and the amount of trimming. If the overall machining time is less than 30 minutes, the cutting condition can also be improved by adjusting the pass speed.

14. What is the role of the cutting fluid?

Metal processing attention plus cooling oil. The function of the cooling system is to take away the heat of cutting and flying debris and to lubricate the processing. The coolant will cut the tropical zone, reducing the heat transferred to the tool and motor and increasing their service life. Take away the flying debris to avoid secondary cutting. Lubrication reduces cutting forces and makes machining more stable. In the copper processing, the use of oily cutting fluid can improve the surface quality.

15. What are the stages of tool wear?

Tool wear is divided into three phases: initial wear, normal wear, and sharp wear. In the initial wear stage, the main cause of the tool wear is that the temperature of the tool is low and the optimum cutting temperature is not reached. At this time, the wear of the tool is mainly abrasive wear. Such wear has a large influence on the tool, which easily leads to tool collapse. Knife. This stage is a very dangerous stage. If it is not handled well, it may directly cause the tool to collapse. When the tool passes the initial wear period, the cutting temperature of the tool reaches a certain value. The main wear is diffusion wear, and its main effect is to cause partial peeling. Therefore, the wear is relatively small and relatively slow. When it wears to a certain extent, the tool fails and it enters a period of sharp wear.

16. Why should the tool be run-in and how to run it in?

Above we said that the tool is very easy to collapse during the initial wear stage. In order to avoid the phenomenon of chipping, we must run the tool. The cutting temperature of the tool is gradually increased to a reasonable temperature. It has been experimentally verified to compare using the same processing parameters. It can be seen that the tool life has increased more than 2 times after running-in.

The method of running-in is to reduce the feed rate by half while maintaining a reasonable spindle speed. The machining time is about 5 to 10 minutes. Take small values when processing soft materials and take large values when processing hard metals.