1. CNC positioning management method: Lay a smooth and clean white cardboard on the workbench, and set the laser cutting head above it. The height between the focusing lens and the cardboard is smaller than the focal length size of the focusing lens. For example, if the focal length of the focusing lens is set around the distance from the cardboard. The CNC system sets the cutting head to move once along the x-axis or y-axis, and the z-axis rises 1mm simultaneously. The continuous movement distance can be set to 20 times. Each time it moves into place, use a laser to emit a pulse laser and punch holes in the cardboard. Move 20 times and punch 20 times to raise the z-axis height. By observing these 20 holes, it can be observed that the diameter of the holes changes gradually from large to small, and then from small to large. Finding the location with the smallest hole diameter is the focal point for recording this point. The distance between the cardboard and the lens measured at this position is the actual position of the laser beam focus.

2. Oblique burning method: Place the flat plate diagonally on the workbench, with an inclination of about 10 degrees. Set the cutting head at point A, where the height dimension from point A to the focusing mirror is smaller than the focal length dimension of the focusing mirror. The CNC system sets the cutting head to continuously move horizontally along the x-axis or y-axis. When the movement starts, the laser outputs a continuous laser and the cutting head stops moving. This is the burning mark of the laser beam from wide to narrow, from narrow to wide. Record the narrowest trace as the focal point, and the distance between the measuring plate and the lens is the actual position of the laser beam focal point.

3. Direct combustion method: Hold a flat plate and stand at an angle of 85 degrees on the cutting workbench. Raise the cutting head to a focal length of about 1.5 times the surface of the workbench, open the laser door, continuously output the laser beam, and quickly move it horizontally to the focusing mirror. You can see the burning marks of the laser beam from wide to narrow, and from narrow to wide on the surface of the plate, which is very close to the changes in the laser beam focusing process. Take the narrowest trace as the focal position and record it. The distance between the measuring plate and the lens is the actual focal position of the laser beam. This method requires manual operation, so be careful of safety to avoid causing human injury.