The Difference Between a Laser Cutter and CNC Router
The projects you see on Instagram and Pinterest such as wooden signs, cutting boards, and 3D spectacles go through a series of processes before coming out finished and photo-ready for social media. One of these major processes is cutting—an inevitable part of their production. And like any business or crafter, finding the right machine to get the job done is crucial.
There are two go-to machines that fall into the category of fast cutting machines—a CO2 laser engraver and a CNC router. You would always find these two machines or at least one of them in the workshop of a cutting industry. The major similarity between these machines is that they both make use of CNC programming in their operation. But with few similarities come many differences that set them apart. The CO2 laser/CNC machine comparison has been made by many, but we will offer some expert-driven answers.
A Brief History of CNC and Laser Cutters
Western Electric championed the very first commercial production of a CO2 laser machine dating back to 1965 as it was used to cut through a 1mm sheet of metal. It has evolved to become a force to reckon with; it can now cut through hard and thick materials like ceramic and glass, as well as wood, leather, and acrylic.
In a similar manner, the CNC (Computer Numerical Control) machine was a major breakthrough for the rapid manufacturing and production sectors in the 1940’s. In the early days, punched tape was used to input data into the CNC machine, but this evolved into analog computers and now digital computers for better automation. In all, these two cutting machines have come a long way and this article will teach you all there is to know about them. Sit tight and let’s get right into it!
Working principle of CO2 laser/CNC Machine
How Does a CO2 Laser Engraver Work?
This machine uses intense light rays amplified through mirrors and lenses to produce enough energy to cut through various materials. The process of producing the laser beam leads to the power of the machine’s laser tube. This laser tube contains a diode that charges up a mix of CO2, helium, hydrogen, and nitrogen gas to produce a burst of invisible, infrared light energy which the mirrors reflect forward and backward.
This laser beam then reflects off of three mirrors within the machine until it reaches the laser head. Upon reaching the laser head, a convex focal lens magnifies the power of the laser beam and streamlines its focus to a single point for cutting. This machine cuts without the laser head touching the workpiece (non-contact cutting).
How Does a CNC Router Work?
A CNC router is a computerized tool that can cut/carve objects onto the surface of different materials such as wood, metal, etc. All that is needed is to send the design into the machine and allow the cutter to do the rest. The machine works with the three cartesian coordinates to control its motion and operation. This is also similar to the CO2 laser engraver, but with some slight differences, starting with its mode of cutting (contact cutting). The spinning metal cutter/bit must touch and remain in contact with the workpiece throughout the period of cutting.
Unique Selling Points
Here is a subtle comparison of CO2 laser/CNC Machines to help you make the best choice either as a motivated hobbyist or an eager business owner. The key qualities to look out for are listed below:
The degree of accuracy that comes with using a CO2 laser engraver is unrivalled. It compares to using a 0.1 mm thick sharp knife to cut through a material while using a CNC router is similar to using a 1 mm thick knife. More so, since a CO2 laser engraver would have no direct contact with the workpiece, it will minimize any possible wear to the workpiece during cutting unlike a CNC machine. This means that for very detailed and intricate cuts, a CO2 engraver is the best choice.
For power consumption, the CO2 laser requires less power and is ready-made for connection to a one-phase outlet (110V). The CNC machine consumes more power and also needs a three-phase outlet (220V) for its connection and such connection is synonymous to industrial settings only. A CO2 laser engraver is partly domestic and industrial while the CNC router is fully industrial. What this simply implies is that you can save up to thousands of dollars in running cost when using a CO2 laser engraver due to its high energy efficiency.
In terms of speed, there is not much of a difference, their cutting speed largely depends on the workpiece being cut. But the CNC machine can make quicker passes due to its typical large size during cutting than a CO2 laser machine. OMTech’s CO2 laser engravers have a cutting speed that ranges between 1-40 mm/s depending on the power. While a typical CNC Machine cutting speed ranges from 7,000-18,000 rpm.
Nature of Workpiece
When working with materials like PVC and foam, using a CO2 laser would not be appropriate because of how it reacts with PVC to produce harmful gases. This limits the usage of a CO2 laser engraver; whereas, a CNC machine does not negatively react to any type of material. You just need to attach a dust collector to the CNC machine to avoid dust flying around. Yet, the CO2 laser engraver makes up for this shortcoming by being able to engrave around circular materials such as tumblers, mugs, and bottles which a CNC router cannot do.
A CO2 laser engraver is fully cased such that even in case of fire, it is confined. But a CNC machine is often open and exposed to the immediate environment. Whatever the case maybe, always adhere to the manufacturer’s instruction when operating both CO2 laser/CNC Machine. Keep the environment clean and chips-free at all times during the operation of these machines. Another upside to a CO2 laser engraver is how the lifespan and efficiency can be greatly improved by using upgraded air assist features or a water chiller.