Adjust the Focus of Metal Laser Cutter – A Practical Guide

When the customer uses the Metal Laser Cutter, the focus is not adjusted properly, which affects the use effect of the Metal Laser Cutter, delays production efficiency and working time. The laser focus numerical control positioning method, the bevel focus burning method, the laser cutting direct burning method, three methods Tell everyone to solve the problem of focus adjustment.

How to Focus Metal Laser Cutter

CNC positioning and spotting method for laser focus 

Numerical control positioning and dotting method: Use a piece of flat and clean white cardboard, spread it on the worktable, set the laser cutting head above it, and the height of the focusing lens from the cardboard is about 10mm smaller than the focal length of the focusing lens, such as focusing. The focal length of the mirror is 127mm, so set the focusing lens to about 117mm from the cardboard.

The numerical control system sets the cutting head to move once every 10mm along the X-axis or Y-axis, and the Z-axis rises 1mm at the same time each time it moves, and the distance of 20 consecutive moves can be set. Each time it moves into position, a total of 20 holes are punched in 20 times, and the height of the Z axis is increased by 20mm.

Observing these 20 holes, we can find that the diameter of the holes changes from large to small, and then from small to large. Find the position with the smallest aperture as the focal position, and record this. Measuring the distance between the cardboard and the lens at this position is the actual focus position of the laser beam.

Inclined focus burning method 

Inclined focus burning method: This method indicates that it is such that a straight wooden board is placed on the workbench at an inclination of about 10 degrees. Set the cutting head at point A. The height of point A from the focusing lens is 20mm smaller than the focal length of the focusing lens. The numerical control system sets the cutting head to continuously move horizontally along the X-axis or Y-axis by 230mm. The laser will output when the movement starts. 200W continuous laser, when the cutting head stops moving, the laser also stops.

At this time, you can see that there is a burnt trace of the laser beam that changes from wide to narrow, and from narrow to narrow. Take the narrowest part of the trace as the focal position, record this point, and measure the distance between the plank at this position and the lens is the actual focal position of the laser beam.  

Laser cutting direct burning method 

Direct burning method: This principle is to hold a flat wooden board and immediately make an 85-degree angle on the cutting table surface, and raise the cutting head to the position where the focusing lens is about 1.5 times the focus of the table surface. Turn on the laser shutter, continuously output 200W laser beam, move the board horizontally and quickly below the focusing lens, you can see that there will be a burn mark on the surface of the board from wide to narrow, and from narrow to wide before and after the laser beam is focused. The change in the focusing process of the laser beam is very close.

Take the narrowest part of the trace as the focal position, record this point, and measure the distance between the plank at this position and the lens is the actual focal position of the laser beam. Because this method requires manual operation, it is necessary to pay special attention to safety to avoid human injury.

Regardless of the method used, achieving proper focus is essential for obtaining high-quality cuts and maximizing the efficiency of the Metal Laser Cutter cutting process. Operators should follow manufacturer guidelines and safety protocols when adjusting and focusing the laser cutter to ensure optimal performance and safety.