The world of laser engraving can be an overwhelming venture when first starting out. After ensuring that the laser is set up correctly with correct calibration and alignment, one of the biggest questions many users have is what settings to use for their material? Fortunately, there is an easy way to find out this answer and it can be used universally for virtually all types of materials.
If you are starting from scratch with no frame of reference on what power settings to use on a particular type of material, the best way to find out where to begin or find the best range of settings that may work for the application is to engrave a laser power grid. A laser power grid is a matrix of small squares engraved onto the material surface. Each grid square is engraved with it's own unique combination of power and speed settings. The idea is to run as many combinations of power/speed settings as needed to find the best combo of settings or range of settings that will work best for the application in your particular laser.
Here is an example of a general-use laser power grid:
Within the grid, the user will be able to visually select the grid square that works best on the material and at the same time see the progression of laser settings leading up to that "best" setting combo, as well as what to expect if the settings go too high.
Often, several grid squares/ laser settings will show good results. When this happens, a range of settings is shown. When a range of settings shows best/equivalent results, this demonstrates that the material has more forgiveness when engraving and there is "room" to adjust the settings if necessary.
A great "universal" way to use the power grid would be to run the range of power/speed settings starting from 10% power/10% speed, and run up to 100% power/100% speed, showing 10% increments of every combo of settings in between.
One of the most common ways these can be run is by using the color mapping feature, if the laser driver/software is equipped with this function:
When using the color mapping function, each power/speed combination increment (grid square) is assigned an RGB color value for each of the squares. Example: the 30% power/ 50% speed square (see first grid figure) would be designated the RGB values: R=147, G=147, B=147 (see second grid figure).
In some cases, it may not always be necessary to run the power grid as a full 10-100% range. The grid can be narrowed down to a range that may be more appropriate for the specific application. For instance, when using Cermark Laser Marking spray or paste, this product typically needs high power and low speed to bond properly to the material surface. In this case, a grid that ranges from 60-100% power, 10-50% speed and show 5-10% increments between each grid square may be more appropriate.
When running a laser power grid for the first time, it is recommended to use a piece of the production material (or product blank) to run the test so that a complete picture of settings or range of settings will work best for the material or product and its application. The power grid test piece can then be kept as a reference guide for future use as well as used to inspect finished pieces along the production run.
In summary, the benefits of running a laser power grid are:
- Creates a complete picture of laser engraving capabilities on the material.
- Creates a complete visual guide (or specific guide when using closer defined settings) of engraving results that can be expected on the material.
- Takes out the guess work of finding the best laser settings and/or settings to start with on the material.
- Use to inspect finished pieces or products throughout the production run.
- Creates a visual reference to help monitor the health of the laser tube through long-term use.