Deep Hole Marking: A Comprehensive Guide

The guide provides practical solutions to common problems associated with deep-hole, small-diameter marking, including lens selection, parameter setting, and more. It covers laser lens selection, techniques for adjusting the focal length, and optimizing power parameters to help users resolve problems such as blurry markings on the inside of deep holes and poor equipment compatibility.

Why is it so hard to drill deep holes with small diameters?

Anyone who has ever done deep-hole drilling knows that the smaller the diameter of the hole and the deeper it is, the more likely it is that the drill will break.Either the markings are indistinct, or the laser head hits the walls of the holes, which can even damage the surface of the material.The two main reasons are that the lens focal length is inappropriate, so the laser energy cannot be precisely focused, and that the parameters are not properly set, so the power and speed are not matched, resulting in either insufficient energy or burning the material.

Lens selection: Don't let the focal length "hold you back.

A telephoto lens is the first choice.

The key to deep hole drilling is "reaching the target.A standard short focal length lens (such as 100 mm) has no problem with shallow holes, but when the depth exceeds 5 mm, it becomes powerless.At this time it is suggested that one change to a long focal length lens (such as F = 160mm or 200mm). This can increase the working distance, avoiding collision between the laser head and the wall of the hole.

Don't ignore the material.

When marking metal, the high temperatures produce debris that can easily stick to the lens.It is recommended that you use coated lenses, such as anti-reflective coatings (AR coatings), which reduce energy loss and prolong the life of the lens.From personal experience, cleaning the lens once a week with a dust-free cloth can reduce the problem of blurred vision by 80 %.

Details make or break the deal.

Don't turn up the power too high.

Many people think that the higher the power, the clearer the marking will be. In fact, in deep hole environments, too high a power will actually cause scattering of the energy.For example, when marking deep holes in stainless steel, it is suggested that one start with a 30 % power setting and gradually increase the power while observing whether the reflection at the bottom of the hole remains uniform.

Speed and frequency must be coordinated.

When deep holes are being drilled, it is recommended that the scanning speed be reduced (to below 200mm / s), while the frequency is increased (to above 50kHz).This method guarantees that the laser energy is concentrated, while also preventing the material from being oxidized and darkened by prolonged exposure to the laser.Tests have shown that slowing the speed by 50 millimeters per second will increase the contrast of the marks by 15 % or so.

Avoiding the pitfalls: Don't make these mistakes.

1. The camera is crooked. Be sure to use a level when installing the camera. If the camera is tilted more than 3 °, it will cause the marker to shift.

2. Ignoring environmental temperature: In high temperature environments (over 35 ° C), it is recommended that the machine be turned off for 10 minutes every 2 hours of operation.

3. Copying parameters: Parameters for different materials can differ by a factor of two or more.

Finally, when you encounter a particularly deep hole (for example, more than 15 mm deep), you can try the "sectional marking method": first mark the upper part and then adjust the focus and mark the lower part. This is much more successful than trying to do it all in one go.