Adjust the focal length of laser and cutting material

Laser cutting machine for cutting before, must first adjust the focal length of the laser and cutting materials. Up and down the focal length of migration, however, often leads to the material cutting different below. More than one, laser cutting machine for cutting the focus in the workpiece surface: this way, we also become negative focal length, because the cutting point is not located at the surface of the cutting material is not located in cutting material, but the location is at the top of the cutting material. This way, the main use and cutting thickness of the material of high. This way the focus position is at the top of the cutting material, mainly because of thick plate need to cut into the picture, otherwise the nozzle conveying oxygen, so it's easy to lead to lack of cutting temperature decline. But one disadvantage of this approach is that the cutting surface is rough, not very practical in high precision cutting. Second, laser cutting machine for cutting the focus in the workpiece surface: this way has become a focal length, usually found in carbon steel workpiece such as cutting, using the focus of the laser cutting machine to choose when close to the surface, this mode of workpiece surface smoothness, up and down in general relatively close to the focus of the cut surface is very smooth, and focus away from the cutting surface is rough. This mode should be according to the practical application of the technical requirements of the upper surface and under surface. Three, laser cutting machine for cutting the focus below the surface: this way has become a focal length. When you need to cut the artifacts often used for stainless steel or aluminum plate cutting points inside the workpiece model. But one disadvantage of this approach is that the focus principle of cutting surface, cut relatively bigger than cutting point on the workpiece surface, at the same time, this mode requires cutting air flow, temperature to the foot, cutting punch time slightly long point. So when you choose the material of workpiece mainly for stainless steel or aluminum lamp high hardness material selection.