How to Adjust the Focus of a Laser Marking Machine

This guide will walk you through the steps of adjusting the focal length of your laser marking machine, including practical tips and solutions to common problems.Mastering the technique of focus calibration allows you to easily solve the problems of blurry marks and uneven depth, significantly improving the quality of the mark and the efficiency of the work.It is perfect for beginners who are just getting used to laser equipment.

Why is the focus setting so important?

Anyone who has just started working with laser marking machines may have had the experience of setting the parameters correctly, but getting blurry or uneven images.In fact, 80 % of the problems are caused by the laser not being properly focused. Just like a camera, the focus of a laser beam directly affects its energy density. A difference of 1 millimeter can make the difference between success and failure.

Preparation for calibration.

Don't skimp on the tools.

First, check whether the work surface is level, and prepare the calibration gauge that came with the machine (or a vernier caliper if you don't have one), a non-woven cloth, and industrial alcohol.A special reminder: Don't use paper towels to wipe your lenses. Residual fibers are even more of a hassle.

Security precautions must be taken.

Put on safety glasses and wear cotton work clothes.Although many machines now have safety locks, it is still necessary to open the protective cover when adjusting them.

Three steps to perfect focus.

The first step is to find the baseline.

Place the test piece in the center of the worktable, and manually raise the Z-axis to the reference height specified by the manufacturer.For most models, the red dot indicator lights up when the camera is focused at the theoretical focal length; this position should be remembered.

Crossing line verification method.

Draw a 10 mm square grid on the film and focus on the intersection of the two lines. If the color in the center is lighter than the surrounding area, the focal length is too long. If the color is too dark, the focal length is too short.Adjustment should be done in quarter-turns of the height control handle.

Step tests determine accuracy.

The pattern consists of five steps, each 0.1 mm wide. The step with the sharpest lines and most even oxidation corresponds to the best focus.The researchers recommend using stainless steel plates, because the reflectivity of copper or aluminum is too strong, and may lead to misjudgments.

They are often called to the scene of a vehicle rollover.

The edges are clear, but the middle is blurry.

Eighty percent of the time, the problem is that the camera is out of alignment. First, check to see if the clamps have pressed the material out of shape.If you are using a rotary fixture, remember to compensate for the height difference caused by centrifugal force.

The colors are like the waves of the sea.

This is not a focus problem, but rather a matter of checking the level of the track.If the error in the X or Y direction is greater than 0.5 degrees, the user should contact the manufacturer.

Suddenly, the focus is wrong.

Don't rush to the repair shop. Check first to see if condensation is forming on the lens.In particular, in the south during the rainy season, the camera should be preheated for 20 minutes before use. If the lens fogs up, blow on it gently.

Maintenance is more important than tuning.

After each use, be sure to put on the dust cover, and once a week clean the lifting guide with a cotton swab dipped in alcohol.If it's raining, just put a few packets of desiccant by your equipment.Remember: a stable focus = a clean lens + a smooth track. If you take care of the two, you can reduce the number of times you have to refocus by 70 %.