Three focus relations of laser cutting machine

Zero focal length

This method is the most common focus position, also known as zero focus, which is often used to cut SPC / SPH / SS41 and other workpieces. When using, let the focus of the laser cutting machine close to the workpiece surface.

In this mode, because the smoothness of the upper and lower surfaces of the workpiece will be slightly different, the cutting surface close to the focus will be more smooth. On the contrary, the cutting surface far away from the focus will be rough. In actual use, it will be determined according to the different process requirements of the upper and lower surfaces.

Negative focal length

This method is also known as negative focal length, because the position of the cutting point is not located on the surface or inside of the workpiece, but on the top of the cutting material.

Generally, when this kind of focus is used, it is due to the relatively high thickness of the plate. If the focus is not located in this way, it may lead to the lack of oxygen delivered by the nozzle, resulting in the decrease of cutting temperature and the inability to cut materials. However, a significant disadvantage of this method is that the cutting surface is rough and not suitable for precise cutting.

Positive focal length

This method is called positive focal length, and the focus mode is generally used when cutting stainless steel or aluminum steel plate and other materials, so that the cutting focus is located inside the workpiece.

The main disadvantage of this method is that the cutting range is relatively large, and this mode often requires more powerful cutting air flow, sufficient temperature and longer cutting perforation time. Therefore, only when cutting stainless steel or aluminum and other materials with high hardness are selected.

In summary, in the process of using laser cutting machine, we choose different focus modes according to the processing needs of different workpieces, which can give full play to the performance advantages of laser cutting machine and ensure the cutting effect.