Perfect Laser-Three focusing methods of metal laser cutting machine

There are three easy ways for metal laser cutting machines to determine the focus position in industrial production:

1. Printing method: The cutting head is moved from top to bottom, and the laser beam is printed on the plastic plate, and the focal point is the point with the smallest printing diameter.

2. Inclined plate method: Use a plastic plate inclined at an angle to the vertical axis to pull it horizontally, and find the minimum point of the laser beam as the focus.

3. Blue spark method: remove the nozzle, blow air, and hit the pulse laser on the stainless steel plate, so that the cutting head moves from top to bottom until the maximum blue spark is the focus.

For the cutting machine with flying optical path, due to the divergence angle of the beam, the distance between the near end and the far end of the metal laser cutting machine is different, and the beam size before focusing is different. The larger the diameter of the incident beam, the smaller the diameter of the focal spot. In order to reduce the change of the focal spot size caused by the change of the beam size before focusing, the manufacturers of laser cutting systems at home and abroad provide some special devices for users to choose:

1. Parallel light tube, this is a commonly used method, that is to add a parallel light tube to the output end of the CO2 laser for beam expansion processing. The beam size is nearly identical before focusing at the inner proximal and distal ends.

2. Add an independent lower axis of the moving lens to the cutting head, which is two independent parts from the Z axis that controls the distance (standoff) from the nozzle to the surface of the material. When the machine table moves or the optical axis moves, the beam moves from the proximal end to the distal F axis at the same time, so that the spot diameter after the beam is focused remains the same in the entire processing area.