Laser Buying Guide
When preparing for the purchase of a CO2 laser, give some consideration to what you are going to use it for. In particular, determine what type of material you want to cut, how thick the material is, and the largest design you want to produce. This will help greatly in the selection of an appropriate model. Keep in mind that these lasers are not intended to cut or engrave metal. They are intended to cut materials such as leather, wood, and acrylic. They can also engrave all these materials, plus glass, stone, and anodized or painted metals. Scroll down to learn about some of the key features you will find on CO2 lasers.
Note: As of publication, all the models above have a Ruida 6442 or a Ruida white-label controller, linear rails on both the X and Y-axis, red-dot guidance, and are 110-Volt.
If you are going to use the laser primarily for cutting, then generally speaking, the higher the wattage the better. Here are links to charts that compare cuttings speeds of various wattages: OMTech Cutting Speed Comparison and Thunder Cutting Speed Comparison (please note that while the second chart is for another laser brand, which I think it is more accurate. The charts are intended to give you a ball park idea of what to expect. Your results may differ).
According to OMTech, expect to cut plywood/acrylic up to 1/2" with a 50W, up to 3/4" with a 60W, and up to 1.0" with an 80W, and 1.2" with a 100W (these results are in a lab, and may require multiple passes, real world results will likely be roughly HALF of the stated cutting thickness).
If you plan to primarily photo-engrave, then you may want to limit your wattage to 60-80W. This is because a higher wattage laser has a wider beam, which results in a larger dot size, and may not produce as fine of detail as a lower wattage laser. With that said, some users have reported that swapping out lenses will narrow the beam and resolve this issue. However, additional lenses are an added cost and do require additional technical expertise.
When buying a Chinese laser, sellers tend to advertise the peak wattage, and not the rated wattage. The difference between peak and rated could be as little as 5 watts and as much as 30 watts (or more). One way you can figure out the actual wattage you are getting is to get the length, diameter, and manufacturer of the laser tube. If the manufacturer is not known, you can use this Generic Tube Chart to help you approximate a wattage.
If you are looking for a high quality, brand name replacement tube, SPT, EFR and RECI are some well known names. Speaking of replacements, it is possible to upgrade laser tubes, but that typically requires replacing the laser power supply, the laser tube mounts, and adding an extension box to the machine.
This is probably the second most important decision after wattage. Most people will suggest to buy the largest laser you can afford, because you can never have too much space. However, there are few things to keep in mind before making a purchase. The first is the location where it is going to be installed. All lasers require exterior venting (and in some cases carbon filters or both), which means it will need to be placed near a window or vent. Most ducts for lasers 100W and under are 6", so a typical 4" dryer vent is too small. The other consideration, is the size of the doorway the unit must be moved through if going into a house or basement. In these instances, a desktop model, or a 20"x28" model that has a removable base, may offer the flexibility you need. Lastly, if you're strapped for space or have a limited budget, consider purchasing a machine with a pass-through. This will give you a little more flexibility to work with oversized objects.
Now that you know the size and wattage, it's time to select your options. Below is a brief list of popular options you may want to consider for your CO2 laser.
Controller: Ruida is by far the most popular controller. One of the reasons is because it works with a popular software package called LightBurn (although LightBurn is compatible with other controllers). Ruida controllers also support the Rotary Setup window in LightBurn which is helpful when using a rotary. Lastly, it is also helpful to have a Ruida Controller when asking for assistance online, because there is a larger user base.
Note: The 50W entry level Preenex/OMTech laser is the only machine that uses a Trocen Controller. I would avoid this model.
Linear Guide Rails on X and Y Axis: Some machines use round rails which are lower in cost, but tend not to have the longer life expectancy of square rails. When possible, look for a machine with linear guide rails.
Red Dot Guidance: This will allow you to see where the laser is going to cut, making alignment easier.
Motorized Z-Axis/Bed: A laser with or without a motorized Z-axis will have the same production capabilities. However, the motorized Z-axis makes raising and lowering the work table to adjust the focal point much easier (it's like having power windows on a car). There are types of options for a motorized Z-axis: 1.) two mechanical buttons on the machine and a motor to raise and lower the work table, or 2.) a driver and stepper motor where buttons on the control panel move the work table up and down. The latter is more convenient and allows the most flexibility, and usually works in conjunction with autofocus. In most cases this can be added later, but it does involve considerable work and research (kits are available for some models).
Autofocus: Autofocus allows you to press a button and have the machine automatically adjust the focal point of the laser. Autofocus is a convenience, not a necessity. Quite frankly, it takes about as long (if not longer) to autofocus as it does manually. Half the time I use it, and the other half I don't. In order to add auto-focus, you must have a motorized Z-axis controlled by a driver and stepper motor (option 2 above). Lasers that do not have autofocus, but have a motorized Z-axis, may or may not have a driver and stepper motor. In most cases this can be added later, but it does involve considerable work and research (kits are available for some models).
Pass-through: A pass-through is a door or doors that allow material to be engraved that is deeper (and in some cases wider) than the bed. A good use for this is if you want to engrave the middle of a park bench slat. You will insert the material through the pass-through doors and let the excess hang out. Using LightBurn, you can also create a design that is longer (and in some instances wider) than your bed using the Print and Cut feature.
Bed/Platform Configuration: There are two types of platforms: knife and honeycomb. A knife table tends to be better for larger and more rigid materials, where a honeycomb platform is better for small parts. Some materials tend to cut better on one versus the other. Unless you know you are going to be working in one type of material, it is a good idea to purchase a machine with both as it can be difficult and expensive to find aftermarket later.
Removable Base: Most of the larger lasers are too wide to go through a standard residential interior door. By purchasing a laser with a removable base, you can rotate the laser on its back, reducing the width to around 24". (Specifications are subject to change, so verify with seller prior to purchase.)
Rotary: There are several types of rotaries: chuck, roller and 4-wheel. While some of listings on eBay say they include a free rotary, technically they are not, and usually you can find another machine for less money. The one they include generally has limited usefulness, and in the case of hot dog style rotaries, they tend to scratch the material. You would be better off foregoing the "free" rotary and putting the money towards a good quality 4-wheel rotary. See Optional Upgrades for more rotary information.
LightBurn Software: Sometimes advertised as a free option like the rotary, I would suggest buying the software direct from Lightburn ($80 at the time of this writing). You will likely save a few dollars in the process and help support a small US based business.
Tube Installation: Some models ship with the tube installed and others do not. As a general rule, if the machine has an extension for the tube on the right-hand side, the laser and the tube ship will separately, and will require you to install the tube and align all the mirrors. If you want a model that should be easier to set up, select a model with the tube pre-installed.
Dual Tubes: There are models, with a large bed size, that have two laser tubes installed. If this is your first laser, I would not suggest this model. Two tubes means a steeper learning curve and roughly twice the set up. They are not as popular, so there are a limited number of people who can provide support for them. While it may be convenient to be able to run two jobs at the same time, you will not have access to the entire bed if you want to run a larger job.
Where to Buy:
Most people purchase their CO2 lasers on eBay and Amazon, or direct from OMTech and HL-Yeah, although there are some good custom builders in China, such as Debin Lee or Coco Song. Most of the lasers are very similar, but they are not all the same. Therefore, do not assume that because one laser has a feature, that another will.
Amazon is usually the highest priced retailer for lasers. eBay and the manufacturer's site tend to offer the best pricing. When buying on eBay, you will see dozens of sellers offering similar lasers, yet many are the same seller marketing under different user names, and it is hard to tell them apart. In the end, they are often selling the same laser packaged with slightly different options or features. Your best bet is to find a seller with the best price, with the item location in the US and offers both FREE shipping and FREE returns. Yes, free returns. If you have a problem, it's nice to have the free return option in your back pocket. If your laser is going to a residence and you are buying on eBay, plan to pay an additional $150 for residential and lift gate fees (so much for free shipping). Some sellers allow a Make Offer option. Give it a try, you might save anywhere from $5-50, but it will take 24 hours to get a response. Lastly, Paypal Purchase Protection does not cover these machines because they are considered industrial equipment, so keep that in mind when selecting a retailer.
Other Costs to Consider:
Purchasing the laser itself is only part of the investment you'll make. Plan to budget another $1000-1500 on recommended upgrades, optional equipment, tools, and supplies, to convert your Chinese laser into a dependable, quality machine. See the section, Recommended Upgrades, for important upgrade information.