Adjusting Laser Power to the Depth of the Carving

To achieve an ideal effect with laser engraving, the depth of the engraving and the power of the laser beam must be perfectly matched.The book explains how to adjust laser power based on the properties of the material and the needs of the carving, and includes parameter testing, solutions to common problems, and suggestions for optimization. It will help you improve the precision and efficiency of your engravings.

Why is it necessary for the laser power to be matched to the depth of the engraving?

Many people who are just beginning to use laser cutting may have had the experience of finding that the same pattern sometimes is too shallow to be seen clearly, and sometimes is burned into the material.The real problem is that the depth of the carving doesn't match the laser power.Simply put, the harder or thicker the material, the greater the laser power needed. But in actual operation, the engraving speed and number of repetitions must also be considered.Take for example the cutting of deep grooves in a wooden board. If the power is set too low, it might take several passes to finish the groove, and the efficiency of the process would be low. The edges of the groove would also likely be rough.On the other hand, if the power is too high, the acrylic sheet may melt.

Three easy steps to precise matching of power and depth.

First, do a small-scale test. Don't rush into the job.

No matter how urgent the job, when you get a new material you have to make test blocks first! Take a scrap piece and mark off different areas for different power levels (for example, every 10 % from 20 % to 80 %), and use the same pattern to engrave them.After the test is complete, gently scrape your fingernail across the surface. If you can feel an indentation and it doesn't scratch your finger, then the power level you started with is a good starting point.This method is especially suitable for flexible materials such as wood or leather.

Adjusting the parameters to suit the materials

The reaction of different materials to a laser beam is quite different.

Soft material (such as basswood or PVC): Suggest 30-50 % power, with high speed (e.g. 200 mm / s), to avoid burning.

- Hard materials (such as metal plating, glass): Power must be raised to 70 % or more, while speed is reduced (to 80-120mm / s) and the number of passes increased by 1-2.

Thin acrylic: Use low power (20-30 %) and multiple passes (3-5), with a 5-second cooling period between each pass.

Dynamic adjustment is more reliable than fixed parameters.

Don't blindly trust others 'specifications! The humidity, the cleanliness of the laser lens, and even fluctuations in voltage can all affect actual results.Here's a tip: If you notice an increase in smoke or an increase in the intensity of the odor while carving, immediately stop and check.This may mean that the power is too high, causing the material to carbonize. The power must be reduced by 5-10 %, and a wet cloth should be lightly wiped over the surface of the material before continuing.

If you encounter problems, check the power settings first.

The edges are either fuzzy or jagged.

Eighty percent of the time, the problem is that the laser doesn't have enough energy to completely cut through the surface of the material.They tried increasing power by 15 % and reducing speed by 20 %, allowing the laser head to stay longer at the corners.

The surface of the material turns yellow or scorched.

This is especially likely to happen when cutting light-colored wood, and is usually caused by a laser with too much power or an improper focus.Don't adjust the power yet, but use a test card to make sure the light spot is the smallest possible.If the focus is still a problem, try reducing the power to two-thirds of the present level.

The depth is uneven.

If parts of the same plane are deeply carved and other parts are shallow, it could be because the worktable is not level or the material is not of uniform thickness.A temporary solution was to increase the power of the machine by 10 %, and to use a caliper to check the thickness of the material before carving to ensure that it did not exceed 0.5 mm.

A formula for lazy people.

Although there are differences between various models, the following formula can be used as a general guideline:

** Basic power (%) = (material thickness in mm x 10) + (material hardness factor x 20)

- Coefficient of hardness: For soft materials (such as foam) use 0.5, for medium materials (such as pine) use 1, and for hard materials (such as stainless steel) use 1.5.

For example, the basic power of a 2mm thick pine board is (2 × 10) + (1 × 20) = 40 %.In actual operation, this figure can be adjusted up or down by 5-10 % based on test results.

And finally, be sure to check the output value with a power meter every time you change materials or after two hours of continuous work. Some older models can suffer a decline in power after prolonged use, and the numbers on the parameter table will no longer be reliable!