Laser cutting is an efficient and precise processing technology that is widely used in cutting and shaping metal and non-metal materials. In the laser cutting process, the determination and adjustment of the focus position are key factors affecting cutting quality and efficiency. The focus is the point where the energy is most concentrated on the surface or inside the material after the laser beam is focused by the optical system. Reasonable focus position can maximize the energy density of the laser beam, resulting in precise, smooth and efficient cutting.

Direct observation method

Printing method: Move the cutting head on the plastic plate or paper and use the laser beam to print. Observe the printed pattern. The point with the smallest diameter is the focus position. This method is simple and intuitive, suitable for preliminary debugging and rapid positioning.

Blue spark method: Remove the nozzle, blow air and turn on the pulse laser, and observe the intensity changes of blue sparks on metal surfaces such as stainless steel plates. When the spark is brightest, it is the focus position. This method is suitable for situations where precise focus is required.

Numerical positioning method

CNC positioning and dotting method: The CNC system is used to control the cutting head to move on the material surface according to a predetermined trajectory, and emits a pulse laser for dotting. By measuring the diameter or depth of the points, find the point with the smallest diameter or the largest depth as the focus position. This method requires precise CNC systems and data processing capabilities.

Bevel cauterization

Place a wooden or plastic board diagonally on the workbench and burn the laser beam to leave marks on the board. Observe the width changes of the trace, and take the narrowest point of the trace as the focus position. This method is suitable for the preliminary debugging stage of quickly locating the focus position.