What Does 'Laser Parameters' Mean?

Optimal laser parameters for CO2 laser engraving & cutting applications

'Parameters'... The power, ppi, Hz, pass, Air Assist and Z-Offset. But what does any of that even mean?


Power & Speed Parameters

The 'speed' and 'power' laser parameters are probably the most important settings within the entire materials database. You can set these as a percentage between 0 and 100%.

The power parameter describes the output of your laser machine. 100% means your laser is running on maximum power. For dark, wooden engravings or even rubber stamps, you generally need to use a higher power. Low values are used for dainty materials like paper. 

The speed parameter describes the movement of the laser head. Faster speeds mean the laser will have less exposure time with the material, and slow speeds means there will be more. For example, a large-scale engraving on TroLase materials are engraved at very high speeds, between 80 and 100%. But detailed photo engravings on wood only use a very low speed, usually below 10%. This setting can also affect the quality of your cut.

Please note: cutting and engraving speeds are not compatible with one another. Basically, cutting is almost always slower than engraving. A 'high' cutting speed would be something like 10%.


PPI & Hz Parameters

The PPI (pulses per inch) parameter determines how many laser pulses are being fired per inch of engraving. To achieve a good result, this really should be the same / a multiple of the dpi setting that is selected in your print setting. If you set this parameter to 'Auto', JobControl will automatically determine the optimal resolution for your laser pulses. 

During the cutting process, the Frequency parameter is recognised and displayed to you in Hz (Hertz). This specifies the number of laser pulses per second. Usually, for a CO2 laser, the value can be set within a rough range of 1,000 to 60,000 Hz. For example, if you wanted to achieve a smooth, polished edge when cutting acrylic, you'll need to be using a higher temperature. That means the value needs to be set to at least 5,000 - 20,000 Hz. However, when cutting wood, a low frequency of something like 1000 Hz is necessary to achieve a bright, perfect cutting edge. 


Pass Parameter

The Pass parameter determines the number of engraving or catting passes to be completed in the one job. Sometimes, it can be advantageous to engrave with a lower power and higher speed. This means that the laser is putting less stress on the material each pass. This approach can be great for things like relief engraving.  


Air Assist Parameter

When laser engraving and cutting, the supply of compressed has the potential to significantly influence and improve your finished results. The Air Assist parameter protects the lens from damage, as it stops dust from adhering to it in the first place. However, there are certain applications where Air Assist needs to be switched off. When engraving TroLase engraving materials, a nicer engraving result can be achieved when Air Assist is disabled. In this case, the lens just needs to be checked and cleaned more regularly to avoid contamination and damage.


Z-Offset Parameter

The Z-Offset parameter is the main focus setting. If the Z-Offset is set to zero, it will be 'in focus', meaning the focus will be exactly on the material surface. However, there are some applications that require deliberate defocusing. For example, when engraving large areas of TroLase, we recommend defocusing by 2mm for a consistent engraving result. Remember, all the following Z-Offset values are possible when engraving - try them out and see how you go: 5mm (table moves up, closer to the material) to 127mm (table moves down, further away from the material).


Helpful Hints for Determining Laser Parameters

Still wondering how to quickly and easily determine the optimal laser parameters for your material? Here, we have summarised some tips and tricks for you to try out.

Laser Parameters Basics and Settings