Modern CO2 Laser Reviewed

If you’ve got a laser cutter, it is highly probable that it uses a laser diode. But more expensive machines use a carbon dioxide laser tube along with mirrors. There was a time when these lasers came in two flavors: very expensive and amazing or moderately expensive and cheaply made. However, we are seeing that even the moderately expensive machines are now becoming quite advanced. [Chad] reviews a 55-watt xTool P2. At around $5,000, it is still a little spendy for a home shop, but it does have pretty amazing features. We can only hope some less expensive diode lasers will adopt some of these features.

[Chad’s] video that you can see below attempts to recreate some of the amazing things xTool did on their product introduction live stream. He was able to recreate most, but not all of the results. In some cases, he was also able to do better.

For example, the device has two cameras and can move the height dynamically. So, for example, the company showed engraving a curved guitar, with the laser moving to accommodate the curve. It also could automatically duplicate a design on multiple pieces, and thanks to the cameras, it was able to correctly position the design on the pieces regardless of their position or orientation.

As [Chad] points out, though, it is more work to align and maintain a tube laser than a solid state one. There is cooling fluid, and mirrors to align and clean. Honestly, if you are doing simple cuts and engraving on flat things one at a time, this might not be worth your money. But if you are using your laser to make money, the efficiency would be a big plus.

He couldn’t reproduce all the tests because he didn’t have the conveyor feeder that lets you cut long items or the riser to cut tall objects. He did, however, engrave tiny text on a grain of rice which is pretty impressive. Of course, with a 55-watt laser, it could cut through most material he tried, too. It did have some trouble with some 18mm hardwood, though.

Of course, you could build your own, but it might be hard to match some of the features. When looking at lasers, don’t forget you can’t just look at power. The laser source counts, too.

14 thoughts on “Modern CO2 Laser Reviewed

  1. WATCH OUT HERE! These lasers are very powerful, and can burn the retnas of your eyes instantly. Eye protection is a must here. CO2 lasers emit a lower frequency infared light. Appropriate eye protection for that particular frequency of light is needed to be safe.

    1. While I agree with your overall note that safety is really important, one interesting thing about exotic lasers is that your cornea and lens are pretty opaque outside of the visible light range, 400-1400nm. A CO2 laser will mess up your eye, but at 10,600nm, it’ll limit its damage to completely cooking your cornea, just like egg whites, and you can get those replaced.
      I used to work in high power laser labs, and the deep UV lasers and CO2 lasers were responsible for some very serious burns, but it was the big visible lasers they were using for chirped pulse amplification that resulted in people with sector blindness because of severe retinal damage.

      With that said, I was surprised to read the statement that if you have a cutting laser it’s probably diode based. Every person I know with a laser cutter has a CO2 based one. I didn’t realize that even big diodes were making serious headway in the market, and that’s pretty cool.

    2. Polycarbonate is opaque to standard CO2 laser tube wavelengths, and most protective safety goggles/glasses are made of polycarbonate, so it’s usually sufficient to wear protective goggles. The windows on CO2 laser cutters are polycarbonate for that reason. Make sure the glasses have side shields.

      You can put an old pair of safety glasses in the beam path (before the lens) and hit “pulse” on the laser to see this in action.

      Additionally, the beam after the lens is expanding, so reflecting off of a cutting surface isn’t an issue (although you should still be careful). The beam before it gets to the lens tube is parallel and will go a fair distance to do damage.

      The big danger is mirror alignment, and the best/safest way to do this is to remove the lens tube and shine a red laser pointer vertically up through the mirror system, then align from the gantry back to the tube using the visible beam. Once that’s done the mirrors will be almost perfect to start, and you can then do the actual beam alignment process with greater safety. Ensure that the red laser is accurately vertical for this.

  2. I recently bought a laser cutter one of the co2 type with a 40W tube I got it from and it only cost £289 with shipping as yet I have not tried it as I need to sort out one of my sheds to make a space for it to go I have had several different diode lasers but most of them tend to exaggerate the actual laser power output by including the power used to run the machine which tends to be around 50% which means most only have ½ of what they claim along with them also claiming it can cut 10mm plywood when you would be lucky to cut 2-3mm ply some of them are now fitting 4 laser diodes that are all mixed together which are better than a single diode, I just hope this machine works as advertised.

    1. Those cheap 40W lasers are great, I’ve had one for 10 years and it’s still going fine. The spec isn’t a lie, they are 40W. CO2 is about 20% efficient, so the tube will draw 200W at full power.

      Speaking of power, keep the current under 18mA, tube will last longer. Swap the mirrors for moly ones, easier to clear.

      Your machine will do anything this one can, aside from things like the curved surfaces that need a powered z-axis and fancy software. 10mm ply is a bit of an ask though, might need 2 passes.

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