So you bought a CO2 laser cutter, now what? Part 1: Research

Home > laser cutter, woodshop > So you bought a CO2 laser cutter, now what? Part 1: Research
December 10th, 2013 | 7 comments

So you’re thinking about getting a laser cutter, but might not know where to start. I was in this exact position a while ago, and really would have liked a bit of guidance without having to pick through page after page of online forums. This series of blog posts are aimed at the regular ol’ people out there looking to get started with their own co2 laser cutter.

I’m no laser expert, so take these posts with a grain of salt. I’m merely sharing my personal experience of buying and using a co2 laser over the last couple years. If you spot something that could be done in a better way, please let me know in the comments below. Keep in mind that I’m a safety third kind of guy…some folks like safety goggles, I like turning power tools off with my chin.

What the heck is a CO2 laser cutter?

laser-diagram
A co2 laser cutter is a fairly straightforward machine. A glass laser tube fires a beam of infrared light [1] that is reflected around a series of mirrors [2,3,4] before passing through a focusing lens and ultimately through the material being cut/engraved [5].

cut-diagram
The laser beam converges to a point as it exits the focusing lens [1], resulting in a very narrow and powerful spot [2] before diverging [3]. The distance between the lens and this super spot is the focal length. A longer focal length yields a longer super spot. Long lenses are a little better for cutting, and short lenses will give you the tightest engraving details.

Cutting at the wrong length can result in less than perfect edges. Too short, and you’ll be using the converging portion of the beam [A]. The opposite is true for too long – you’ll blow out the backside [C]. Getting things just right gives you the best chance at getting a nicely squared off cut [B]. Every lens is a bit different, despite being labeled a specific length. I’ll go into more detail on how to find the exact focal length in the setup and maintenance post. Misaligned mirrors can also wreak havoc with your cut quality, but that’s a different can of worms.

What to think about when buying one

laser-beam-closeup Size and power are the two main specs besides price to look at when selecting what will work for you. I highly recommend getting the largest, most powerful machine that your budget will allow. You can throw a wider variety of projects at a more capable machine.

There are a number of manufacturers out there, with various pros and cons. Our laser was purchased through fslaser.com, so I’ll be focusing on the machine I have experience with. Just for reference, we have a 24″ x 36″ machine with a 90W laser tube. The basics are essentially the same for any co2 laser.

crate-truck
Chinese imported lasers like our own can be a little hit and miss on some of the components. If you’re not one to twist a wire or two together, you may want to consider finding a machine that either includes some support, or add a support package to your purchase. I’ve done a little tinkering to get our machine working the way I like, such as adding extra lighting inside, additional cooling for the water, and replacing one of the power switches after I burned the original out.

I get a lot of people asking how I like the machine. It performs like a champ, running several hours every day over the last two years. The people at FSlaser have been helpful when I had a hiccup or didn’t understand how something worked. Our machine shipped with LaserCut 5.3 software, which can be pretty finicky to work with, or even get working on newer operating systems. I have FSlaser’s Retina3D setup that I need to install, which I have high hopes for. LaserCut’s large file handling is pretty poor, lagging on even a very highly spec’d PC when opening files that aren’t even that large. I’d recommend going with the Retina system if you go a similar route.

Probably my one main annoyance is etching artwork too near the left or right edge can cause the machine to lose its place, resulting in shifted engravings halfway through. I’ve ruined a few nearly finished projects this way, and have since learned to use some spacers off the edge. Having a power outage partway through a large engraving can also be frustrating, but that’s not the fault of the machine…or is it?!

Youtube is a great resource to see examples of what different lasers are capable of. Think about what type of projects you’d like to complete, and where you might source your materials from. For example, if you’re really interested in cutting 3/8″ thick hardwoods, you’d do well to look at the high power machines.

Where to put the monstrosity

back
You’ll need a few things to get your laser up and running like two hamsters in a wheel.

1. Excellent ventilation. A laser is essentially vaporizing the materials you feed it. This is stinky and potentially toxic. Your laser will need somewhere to blow exhaust. I blow ours out a window and it works great. Some residue does eventually build up around the area that is being blown, so venting into your closet full of autographed, presidential white suede slippers might not be a great idea.

2. Power. Our original ancient house with equally ancient wiring was barely enough to keep things running. A modern 20A outlet and possibly a second circuit to run the ventilation blower are recommended.

3. Space. If you opt for one of the larger machines, be prepared – they’re heavy! Our machine is 40″ at the narrowest, meaning standard house doorways are out of the question. A solid surface is also recommended to keep the mirrors aligned. Flexy flooring can actually tweak the entire frame enough to throw the beam out of aliment.

4. Water. You can go for a chiller if your budget allows for one, but I’ve been happy running plain old distilled water. I started with a 7 gallon tank, and eventually added some fans and radiator to keep things cool.

Also in this series:
Setup and Maintenance, pt. 2 of 5
Finding, prepping, and using materials, pt. 3 of 5
Tips for more efficient production, pt. 4 of 5
Add-ons and Mods, pt. 5 of 5