1. Cut the focus above the workpiece
In this way we also become negative focal length, because the cutting point is not located in the cutting material surface is not located in the cutting material inside, but located in the cutting material above. This method is mainly used with cutting the thickness of the material. This way the focus is located in the cutting material above the main, because the thick plate needs to cut large, or the nozzle of the oxygen is likely to lead to lead to lead to insufficient cutting temperature drop. But one of the drawbacks of this approach is that the cutting surface is relatively rough, not very practical for high precision cutting.
2. Cut the focus inside the workpiece
This way also becomes a positive focal length. When you need to cut the workpiece for the stainless steel or aluminum plate when the cutting point is often used in the workpiece inside the model. However, one of the drawbacks of this approach is that the cut surface is larger than the cutting point on the surface of the workpiece due to the principle of the focus, and the cutting flow required in this mode is large and the temperature is long enough to cut the punching time slightly longer. So when you choose the workpiece material is mainly stainless steel or aluminum lamp hardness of the material when used.
3. Cut the focus on the workpiece surface
This method has also become a focal length of 0, generally common in the SPC, SPH, SS41 and other parts used when cutting, the use of the cutting machine when the focus on the workpiece surface close to the surface of the workpiece under the surface smoothness of the workpiece is not the same The cut surface near the focal point is relatively smooth, and the lower surface away from the cutting focus appears rough. This mode should be based on the actual application of the upper and lower surface of the process requirements.
To sum up, we use the laser cutting machine to deal with different parts need to correspond to the use of different focus mode, can play a more laser cutting machine performance advantages.