If you have been shopping for a laser engraver for your engraving business, you might have noticed that lots of laser machines have CNC in their names. In fact, CNC laser engravers seem to be the most popular engravers on Amazon (As you can see from this buying guide).
So what does CNC stand for in laser engravers?
The term CNC is an acronym that stands for Computerized Numeric Control. A CNC laser engraver is, therefore, a laser machine that relies on a computer-aided design software (CAD) to perform the laser engraving. In simpler terms, the laser machine is guided by the software rather than by the hand of the user. CNC laser engravers are therefore easier to operate and they make very precise and accurate engravings.
Types of CNC lasers
CNC laser engravers rely on laser beams that are electrically generated. The laser beam is then amplified and reflected inside a container with a partial mirror. After the beam has generated enough energy, it escapes the container and is then focused via different techniques on the material to be engraved or cut. The different techniques used gives us the main types of CNC lasers. These are;
- CO2 lasers
- Fiber lasers
- Neodymium yttrium aluminum garnet (Nd:YAG)
The CO2 laser was invented in 1964 by Patel Kumar and they have grown to be some of the most popular CNC laser engravers today. The CO2 lasers have high power and this makes them ideal for projects that need high precision, personalization as well as mass production. This would explain why most hobbyists love them. They can also be used for laser engraving and laser cutting a number of materials including but not limited to wood, metal, plastic, and paper.
In CO2 laser engravers, the light that is produced electronically goes through a tube filled with gas (usually a mixture of carbon dioxide, hydrogen, nitrogen, and helium) and has mirrors at both ends. The mirrors reflect and redirect the laser beam to the surface of the material to be engraved or cut.
The reflection of the mirrors in the tube ensures no light is lost and this builds the intensity of the light until it becomes strong enough to partially pass through the reflective mirror. The light from the CO2 laser is invisible to the human eye because it is in infrared form. This light has a very long wavelength which makes it efficient in cutting metal, glass, paper, cloth, and other materials that are suitable for laser engraving.
A fiber laser machine uses an optical fiber as the active gain medium. The optical fiber is typically doped with some rare-earth elements like neodymium, erbium, ytterbium, holmium, thulium, praseodymium and dysprosium. The main difference between fiber lasers and other CNC lasers is that the laser light is generated by an inherently flexible medium.
This allows for easier delivery of the laser beam to the target which can be very handy in laser cutting. Fiber lasers also have an impressively high output of power and this makes it possible to cut an engrave materials that other CNC laser engravers might find too tough. For a more detailed description of fiber laser engravers, refer to this article.
YAG lasers have a wavelength of 1.064 microns. This is almost 10 times smaller than that of a typical C02 laser. This can either be a merit or a demerit depending on the results you need. The small wavelength makes YAG lasers ideal for most metals because the metals will easily absorb the light.
However, if you are looking to engrave material like wood, acrylic, fabrics, plastics, etc, you will need to use a laser engraver with a higher wavelength. Because of the limitations of the materials they can engrave, YAG lasers are typically used for industrial applications. YAG lasers may not be the best option for a home-based laser engraving business because it will limit you on the materials you can engrave on.
Advantages of CNC lasers
CNC lasers are loved by laser engraving hobbyists, professionals, and schools due to their unique advantages. Here are the main advantages of CNC laser engravers;
- It can be used for both thick and thin materials. replacing the collimating lens is all it takes to change the focal point of the CNC laser thereby making it easier to cut thicker materials.
- quicker production and process
- very little or no warping when engraving
- greater accuracy as opposed to other forms of cutting and engraving
- the laser beam has a smaller kerf (cutting diameter) and this makes it possible to cut more parts per sheet of material
Materials that can be engraved with a CNC laser engraver
CNC laser engravers can be used in most of the materials that support laser engraving. The best materials for laser engraving include
I have written a more in-depth guide on these materials and what you need to know about engraving them. Here is the link
So as we have seen, CNC laser engravers can be used for engraving almost any type of material. They are accurate and are great for making custom designs with a quick time around. Check out my buying guide for our recommendations of the best CNC laser engravers to buy for your home-based business.