The choice of the focus position is particularly important because the laser power density has a great influence on the cutting speed. The spot size of the focused laser beam is proportional to the focal length of the lens. In the industrial field, there are three simple ways to determine the cutting focus:
1. Printing method: Move the cutting head from top to bottom, print the laser beam on the plastic plate, and focus on a small printing diameter.
2. Inclined plate method: Use a plastic plate to pull horizontally at an angle to the vertical axis, find a very small point of the laser beam, and focus it.
3. Blue spark method: remove the nozzle, blow air, focus the pulsed laser on the stainless steel plate, move the cutting head from top to bottom, until the blue spark reaches very large.
At present, many manufacturers' equipment has achieved autofocus. The autofocus function can improve the processing efficiency of the laser cutting machine. Thick plate drilling time is greatly shortened. By processing workpieces of different materials and thicknesses, the machine can automatically and quickly adjust the focus to a better position.