Greenst Machinery Co., Ltd. , http://www.nbgreenstmachinery.com
As a craftsman for pure technical and operational considerations, the selection criteria for CNC machine tools generally start from the following aspects:
1. The rigidity and stability of the machine table:
In order to make the machine have sufficient stability and rigidity to avoid vibration, many manufacturers use marble as the material of the bed. Some Japanese manufacturers use steel as the bed. Because the deformation of steel at different temperatures is larger than that of marble, it is unstable. Manufacturers will use compensation in the software to eliminate the loss of precision caused by deformation. At present, most manufacturers use natural marble or artificial marble as the bed. It is recommended to use marble bed equipment. The marble is usually cleaned with detergent and water, and alcohol is not available. After wiping, dry with a dry cloth and wait until the water has completely evaporated before working.
2. Rotation speed and stability of the shaft:
At present, there are two types of shafts for rolling bearings with a maximum speed of 80,000 rpm and the other for air bearing speeds up to 120,000 rpm. If the milling machine should adopt rolling bearing, because its longitudinal bearing is better than air bearing, its drilling chuck is also the focus of procurement. Some drilling chucks are not easy to replace and maintain, and some drilling chucks wear quickly become consumables. Replacement costs are expensive, and some require daily maintenance to waste time. The presser foot of the rotating shaft is also another one, and its life and unreasonable design can cause great troubles. For example, there is no seal between the shaft and the presser foot, which causes the vacuum cleaner to have a large power, which causes waste of the vacuum cleaner purchase or central vacuuming power. It is wasteful and may cause bad chip evacuation in the hole of the board.
3. Table movement accuracy and displacement repeatability:
This is the most important point when choosing. It can't be seen through pictures or ordinary operation. It can only be certified after being purchased. The current equipment can meet the design standard when it leaves the factory. The key is to run one to two years later. The accuracy of the machine is very stable, and the machine tools produced in Europe are better.
4. Feed rate of X, Y and Z axes:
The feed rate is currently a general-purpose screw stepper motor with a speed of 25 meters per minute, while the new product has adopted a servo motor. The high feed rate can increase the productivity by 20%-40%, and the Z-axis speed is affected by the drill bit and The influence of the material being drilled on the feed rate has little effect on production efficiency.
5. Table movement and fixture:
Many mobile fronts of the countertops were mainly guided by rails, and there were also air-floating loads for the movement of the countertops. The airfoil countertops were flexible and easy to maintain, and the procurement was the first choice. The device for fixed-surface circuit board is generally a pneumatic chuck. The design of the chuck has an important influence on the replacement of equipment in the future. Generally, it is not easy to wear, because it is one of the most severely worn parts of the equipment when it is worn. It is easy to replace and debug the wear, including the adjustment of the positioning accuracy of the machine (for the template for milling machine).
At present, there are many manufacturers that provide automatic clamping devices. If you do not have a good equipment maintenance engineer, it is best not to use them. Because the automatic loading and unloading device has high requirements for maintenance engineers, and the current circuit board drilling sometimes takes more than one hour. Domestic is generally not necessary.
How to choose CNC drilling machine and milling machine in circuit board processing
CNC drilling machines and CNC milling machines are an important equipment in circuit board processing. The equipment is expensive. The selection of CNC machine tools is important not only for operation, process setting and maintenance, but also for the quality of the products produced.