How Co2 Lasers Cut
Co2 lasers are very versitile. The laser is highly adjustable. The main components of the laser are the power, speed, Pulses per inch (PPI), and Z depth settings.
The laser has a maximum power setting when you purchase it. The power setting can run the laser at 100% power or anything less than that. Some materials require a setting of only 4% power for example. Knowing your material characteristics is key and will save you a lot of time and material. There are some tables out there to help you get an idea of where to start and beyond that experience comes from testing.
The speed setting revers to how fast the carriage head travels back and forth across the materials. This too is a setting of 1% – 100%. Keep in mind that the difference between the fastest and slowest speed is barely perceptible to the human eye, but can make all the difference in the results. By setting the combination of the proper power and the proper speed is important. You dont want to every use more power than you need. Too slow, however can cause a burning effect.
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The next setting is the pulses per inch (PPI). This too is a setting that the human eye can not pick up. The laser will always look like it is on 100% even if the setting is much lower. However, the effect can be dramatic. A lower setting can actually create a different pattern on your material. Ok, now I’ve described power, speed, and ppi. Last is the Z axis or distance. The Z axis controls the depth you set the cutting table. So, if you have a thick (or deep) material, you would lower the table. A piece of paper being so thin would mean you raise the table. Why? Because the Z axis controls where the laser will focus. Focus is the main point here. If you do not have the proper focus for the laser you will either get bad results or no results all together. The laser has a focal point. The average focal lens is 2″. We begin a project by properly adjusting the Z axis to focus the material 2″ from the carriage head.
There is a limit to how far you can adjust a cutting table. There is also a limit on the size of the cutting table. It is important to know these to know how to set up your job or whether you can run the job at all. We have a cutting table of 24″ x 18″. Jobs can sometimes be run in sections too.
Given the information above we can begin to get an idea of how a job is run. If engraving or cutting paper we might have a setting of 4% power, 100% speed, 500 (or half setting) PPI and focused at 2″ (this last setting will always be 2″ no matter what since we have a 2″ lens). Cutting a hard wood, however may have settings of 90% power, 50% speed, and 800 PPI. Softer woods would be different. You can see how this becomes a bit of an art.
I do want to mention a bit about materials. Not every material can be safely engraved or cut. Off-gassing can be a problem. Some materials put off a gas that is well… Deadly. PVC for instance is one of them. Many plastics have Chlorine in them. This too is bad. Other effects are the gases can negatively effect the mirrors on the carriage. This will fog or damage the mirror. A Co2 laser is set up to have the laser in the back of the unit. The laser is “shot” at a series of mirrors to get it to the carriage head. This is how the carriage head can move back and forth so quickly without effecting the laser or material negatively. The carriage head simply has a mirror aimed down at the material focusing the laser beam downward. Check with us and we can help identify whether the material you are wanting to use is possible.
Beyond the limits described above, there really is so much that can be done with a Co2 laser. Think creatively. Give new life to old materials or items you have laying around the house. Think what it would look like if it were personalized. Or if you have a business now and want to take it to the next level, let us know and we can work together.
Now you know how a laser cutter works. Let us be your expert in fine tuning the results to make everyone happy.
Take a look at our examples page for some ideas.
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