The Science Behind CO2 Laser Engraving Machines

The Basics: Laser Engraving for Beginners

Laser cutting machines make quick work of the once tedious task of engraving hard surfaces. They've proven to be a great asset for engraving operations large and small and have encouraged a number of entrepreneurs to consider opening an engraving business of their own. 

Purchasing a laser engraving machine used to be out of reach for most individuals. Not only were the machines very expensive but they were also large. The installation of one of these older versions of laser engraving machines required a lot of space and power.  

New technology has brought the cost of these machines down substantially, making it possible for smaller businesses and individuals to purchase one. Their size has also been dramatically reduced—some are even available in tabletop or portable versions. 

If you're involved with a company that does commercial engraving, or you're considering starting an engraving company of your own, you probably have many questions about how laser engraving works. This article should give you some insight into how laser engraving machines work, what types of things can be safely engraved with a laser, and whether or not you can make a living doing it.

What Is Laser Engraving? 

Laser engraving is the process of using a laser to vaporize one or more layers of a surface to leave a permanent and indelible mark. Think of the laser as a chisel, but instead of chipping off pieces to get the desired result, the material being removed is superheated and vaporizes into a gas.  

The use of a laser engraving cutting machine allows for very precise engravings and exact control over the depth of the cut. Laser engraving can be used on many different materials to leave an image that will withstand harsh environments without fading or eroding away. 

How Laser Engraving Works 

Laser engraving uses tiny lasers to superheat very small areas of the surface being engraved. This heat is hot enough to melt the top layers of the surface and leave behind a permanent mark. The color of the mark left behind depends on the material being engraved, but usually it ranges from white to grey or black.  

Because laser engraving only heats the area touched by the laser, very precise images can be engraved into almost any hard surface without fear of the image becoming blurry or losing detail. The use of computer-generated controls allows for an even more precise cut. 

Computer-generated controllers give the operators complete control of the image being produced without worrying about their own ability to keep their hands steady during the process. Simply upload the image to be produced, set the parameters, and let the computer guide the laser to create exactly what you were looking for. 

For those who are new to laser engraving, look for machines that are simple to operate without sacrificing accuracy or speed. Although the cost of the machine will be a factor in your decision-making process, it should not be the only one. You should also consider ease of use and reliability. A laser engraving machine won't do you much good if you can’t figure out how to use it, or you spend most of your time waiting for the repairman to arrive.

How CO2 Laser Engraving Machines Work

As you begin your search for the perfect laser engraving machine, you will discover there are several basic types for you to choose from. Your best option may be carbon dioxide (CO2). Modern CO2 laser engraving machines have glass tubes that create powerful laser beams.

How do CO2 laser tubes work?

Glass CO2 laser tubes are filled with a mixture of CO₂, nitrogen, and helium gases; they also have a mirror at one end and a lens at the other end. A narrow chamber is left in the middle for cooling water to pass through, which keeps the laser from overheating. 

The gas mixture has powerful conductive properties, and when electricity is introduced, the gases become very excited. The gas particles begin bouncing around the tube with extreme quickness. Their rapid motion quickly builds up great pressure inside the narrow chamber, and the electrical charge forms a beam of infrared light that is invisible to the human eye. The excess pressure and the mirror force the laser light toward the path of least resistance — out the laser tube lens towards the first laser mirror. Although invisible, this light is now hot enough to melt most materials.

The laser beam will then bounce off of three laser mirrors before passing through one final focal lens before it can engrave your workpiece. 

Why Glass CO2 Laser Tubes are the Best Choice

When considering CO2 engravers, there are two types—those with glass tubes and those with metal. Both types of CO2 engravers have their own distinct advantages and disadvantages.

Laser engravers powered by CO2 glass tubes are a good choice for many reasons, including: 

• Affordability. Laser engravers that use CO2 glass tubes are among the least expensive on the market but still offer high-quality and accurate engraving. 
• Longevity. CO2 tubes can last up to 8,000 hours of average use before needing to be replaced. 
• Integrated Cooling System. Turns out that creating lasers hot enough to melt stone produces a great deal of heat in the tubes themselves. An integrated cooling system keeps the tube cool enough to prevent them from being damaged. 
• Uses Direct Current. No need to install a unique power source for this type of laser engraver. 
• Produces Continuous and Steady Lasers. 

Those with metal tubes offer the following advantages: 

• Can Be Used At Lower Power. This allows the lasers produced by metal tubes to be used on more delicate materials. 
• More Accurate. The type of beam produced by metal tubes is slightly more accurate but the difference would not be noticeable in most applications. 
• More Durable. This makes them better for large-scale operations where the additional cost can be offset by a longer lifespan. 
• Pulsating Lasers. This gives them a slight power advantage over the lasers produced in glass tubes but may also lead to jagged edges in softer materials like acrylic. 

Laser Engraving Mirrors 

The CO2 laser tube fires a laser beam about the same width as a standard pencil. Once the beam exits the tube, it reflects off of three mirrors which play a vital role, directing the laser beam to move throughout the workbed in a predesignated sequence. Laser engraver mirrors must be highly reflective and durable enough to withstand the heat generated by the bouncing waves of light within the tubes. They also need to be kept in top working condition.

When engraving with a laser, vaporized materials, oils, and dust can build up on the mirrors. This build-up will reduce their ability to reflect beams of light. This leads to an increase in the amount of energy required to achieve the power level desired. 

To avoid this, the mirrors should be thoroughly cleaned in place on a weekly basis—more if the machine is used heavily. Eventually, cleaning will not return the mirrors to their original shine. At that point, it is time for them to be replaced. 

Laser Focus Lenses 

One of the most important aspects of successful laser engraving is the focus of the lens. Much like you need to focus a camera lens in order to get a clear image, the laser’s lens must be focused in order for you to get an accurate and crisp engraving. 

When a laser beam leaves the CO2 tube, it travels in a wide beam. This beam must be focused to a narrow point which increases its power and accuracy. This is where the lens comes into play. 

The third mirror reflects the laser beam downward toward the focal lens, which utilizes a convex shape. As the beam passes through it, the lens focuses the laser beam to an extremely narrow point, concentrating it into a more accurate and intense beam. Finally, the laser beam reaches the workpiece and begins to engrave or cut the specified design.

CNC Technology

CNC stands for "Computerized Numerical Control" and it is a technology that is widely used in the manufacturing industry to move tools from one area of the workbed to another with accuracy and speed. All operators need to do is input the appropriate parameters and CNC technology will move the tools to exactly the right place at exactly the right time to create the finished product. 

CO2 laser engravers utilize CNC technology to move the laser head around the workbed. These laser machines have a mobile gantry system along the X and Y axes that guides the laser head in particular motions, translating the preset design into laser head movements that trace and produce the desired image onto your workpiece. This technology is a great service to laser engravers. All they need to do is scan an image into the machine. The CNC technology will do the rest. It will automatically move the laser beam to the correct areas at the correct power levels to ensure a precise cut and depth to recreate the image.  

What Materials Can You Laser Engrave?

Now that you understand a bit more about how laser engraving machines work, you may be wondering exactly what material can safely be engraved with a laser. The truth is that there are many materials that can be engraved with a laser, but there may be more effective ways to create an image on some softer materials. Materials that are commonly engraved with a laser include: 

• Wood 
• Cork 
• Slate 
• Glass 
• Marble 
• Granite 
• Ceramics 
• Mirrors 
• Acrylic 
• Some metals 

Additional materials that can be laser engraved, but could be marked in more effective ways include: 

• Rubber 
• Plastics other than acrylic 
• Cardboard 
• Paper 
• Whiteboards 
• Food 
• Fabric
• Leather  

How Long Does It Take to Laser Engrave? 

With a machine capable of running at professional speeds, laser engraving is a rapid process, but the exact amount of time required depends on the size and the intricacy of the project. A small, simple project, like engraving a small logo on a shot glass may take a minute or less. A larger, more complex project, like engraving an enlarged photo onto a large piece of slate may take as long as an hour. 

Is Laser Engraving Permanent? 

Yes. The laser engraving machine creates permanent raised marks on the material by removing some of the material's surface. This creates an image that will last just as long as the material itself. It will not fade or wash away. 

Is the Laser Engraving Business Profitable? 

Like most businesses, running a profitable laser engraving company requires good ideas, good help, and professional equipment, as well as a willingness to work hard to achieve your goals. That being said, if you already have the idea then, yes, with the right people using the right laser engraving machine, starting an engraving business can earn you a comfortable living. 

But what is the right laser engraving machine? The right laser machine for a startup company is one that is affordable, reliable, fast, and easy to use. 

The most cost-effective laser engraving machine does not necessarily mean the least expensive. In order to see a rapid return on investment for the purchase of your machine, it must also be reliable and durable. Downtime for repairs or replacement parts can be devastating for your bottom line, especially if you disappoint your customers by missing deadlines. 

A machine that is easy to use means you will lose less time trying to figure out how to get projects done and more time completing projects. A machine that gets each project done quickly and correctly the first time increases your potential income. 

If you want to succeed as an engraving professional, then you need to think like one. Find a laser engraving machine that will give you consistent, professional-quality results in a timely manner, and you are off to a good start. 

How Much Does a Laser Engraver Cost?

Now it's time to get down to the all-important startup costs of your potential engraving business. Just how much does a good laser engraving machine cost? 

The prices for laser engraving machines vary widely depending on the number of features they offer and their quality. 

Industrial type laser engravers can cost several thousand dollars, but for those looking for an affordable option to get into the engraving business, the prices are substantially lower (from around $300 to $5,000). Keep in mind, though—you get what you pay for.

While the more expensive options may come with more bells and whistles, some of these features may be things you do not need and therefore may not be worth paying for. That is not to say that the least expensive option is automatically your best choice. 

Some of the less expensive laser engravers on the market are cheaper for a reason. They may not be manufactured from high-quality components, or they may not have some of the basic features that you will likely need. The first issue may lead to too much downtime or poor-quality results. The latter may leave you and your customers frustrated when you cannot produce the results they were looking for in a timely manner. 

What you need is a reliable laser engraving machine that can produce quality projects at a price you can afford.  

Where to Buy an Affordable Laser Engraver 

There are many companies that manufacture laser engravers, but none offer the combination of quality and affordability that you will find at OMTech Laser. 

With a large selection of laser engraving machines, from portable desktop machines to mid-level to high-powered industrial, you are sure to find the best machine to meet your needs. All of our machines are manufactured from high-quality components to provide you with years of reliable service.

The intuitive Ruida controller that is included with many of our models makes these machines a breeze to use. With the digital display, you can change the laser head and the laser’s power level, as well as adjust to different materials to ensure accurate images. The controller also monitors the current to determine any faults. This way, the issue can be addressed before any damage is done to the tubes or the power supply. 

Best of all, OMTech Laser offers great laser engraving machines at affordable prices. Check out our selection of laser engravers priced under $5,000: 

1. 55W COMPACT CABINET LASER ENGRAVER WITH MANUAL FOCUS. This machine may be small in size but not in productivity. Small enough to fit into almost any workspace, it still offers a large workbed and can be accessorized with a rotary engraver for those who want to work with mugs or glasses.
2. 60W CO2 LASER ENGRAVER WITH MOTORIZED WORKBED LIFT. This is a midsize option and can work on larger pieces. It offers motorized focus and is versatile enough for most small business applications.
3. 100W LASER CUTTER WITH MANUAL FOCUS. Built to handle almost any professional job, this laser engraver boasts a 100W laser tube that can cut materials up to 10mm thick and has an 11” workbed depth to fit taller items.
4. 80W CO2 LASER ENGRAVING MACHINE WITH AUTOFOCUS. This machine has a lot to offer. It has a huge workbed and 4-way pass-through doors to accommodate almost any project. Its 80W Co2 laser tube works great whether you are cutting or doing precision engraving. The auto focus feature—a sensor that automatically adjusts the focal distance settings—allows you to work more quickly and accurately. This reliable machine is the right choice for anyone who wants to run an engraving business.

If you are serious about getting started in the engraving business, contact us at OMTech Laser. Our knowledgeable staff can guide you through the process and find you the right laser engraving machine to meet both your needs and your budget. They can also inform you about our financing program that offers generous rates, which can help get your laser engraving business started for a low monthly payment.