CNC machining problems and Solutions

1. What are the key points of CNC engraving and CNC milling?

Both CNC engraving and CNC milling are based on milling principle. Focus on the use of tool diameter, CNC milling commonly used tool diameter boundary is 6-40 mm, while CNC engraving tool diameter is 0.2-3 mm.

1. Is CNC milling only for rough machining and CNC engraving only for finishing?

Before answering this question, let’s first understand the meaning of the process. The amount of rough machining is large, while the amount of finishing is small. Therefore, some people habitually regard rough machining as “heavy cutting” and fine machining as “light cutting”. In essence, rough machining, semi finishing and finishing are the meaning of technological process, which represent the different processing stages. Therefore, the exact answer to this question is that CNC milling may as well do heavy cutting or light cutting, while CNC engraving can only do light cutting.

1. Can CNC engraving process be used for rough machining of steel raw materials?

To infer whether CNC engraving can process a certain raw material, the key point is to see how large a tool can be used. The cutting tool used in CNC engraving determines its comparative cutting strength. If the mold form allows the use of tools with a diameter of more than 6 mm, it is proposed to use CNC milling first, and then use engraving to eliminate the remaining raw materials.

1. Whether adding a speed increasing head to the spindle of CNC machining center can complete the engraving process?

It can’t be over. This kind of product appeared in the exhibition two years ago, but it was impossible to complete the carving process. The main reason is that the design of CNC machining center studies its own tool boundary, and the overall structure is not suitable for engraving. The main reason for this mistake is that they mistook the high-speed motorized spindle as the only feature of a successful engraving machine.

1. CNC engraving may use a tool with a small diameter. Can it replace EDM?

It cannot be replaced. Although engraving reduces the tool diameter boundary for milling, small molds that used to only be machined by EDM can now be completed by engraving. However, the length / diameter ratio of engraving tools is usually controlled at 5:1. When using small diameter tools, only a very shallow cavity can be machined, while EDM has almost no cutting force. As long as the electrode can be made, the cavity can be machined.

1. What are the key factors affecting the carving process?

Machining is a complex process, and there are many factors affecting it. The key points are as follows: machine tool characteristics, cutting tools, control system, raw material characteristics, processing technology, auxiliary fixture and surrounding environment.

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

CNC engraving processing is milling processing first, so the control system must have the control strength of milling processing. For small tool machining, feed-forward performance must be provided at the same time, and the path speed can be reduced in advance to reduce the tool breaking frequency of small tool. At the same time, the cutting speed should be increased in the smooth path section, so as to improve the engraving efficiency.

1. What characteristics of raw materials affect processing?

The key factors affecting the engraving performance of raw materials are the type of raw materials, hardness and toughness. The category of raw materials includes metallic raw materials and non-metallic raw materials. In general, the higher the hardness, the worse the processability; the higher the viscosity, the worse the processability. The more impurities, the worse the processability, the greater the hardness of the particles inside the raw materials, the worse the processability. A general rule is: the higher the carbon content, the worse the processability; the higher the alloy content, the worse the processability; the higher the content of non-metallic elements, the better the processability (but usually the nonmetal content in raw materials is strictly controlled).

1. Which raw materials are suitable for carving?

The non-metallic materials suitable for carving include plexiglass, resin, wood, etc., while those unsuitable for carving include natural marble and glass. The metal raw materials suitable for engraving include copper, aluminum, mild steel with hardness less than hrc40, and those unsuitable for carving include quenched steel, etc