The difference between CNC engraving and laser engraving
Many people always mistake a CNC engraving machine and a laser engraving machine as one and the same thing. In fact, there are many differences between these two types of machines. Definition Laser engraving machines are based on CNC technology, where the laser is the processing medium. The laser source emits the laser light and the CNC controls the laser head and motor to move the optical elements on the laser head, mirror, lens, etc. so that the focal point moves in the X, Y, and Z axes of the machine. The material to be processed is instantly illuminated by the laser. The processing is achieved through the physical modification of melting and vapourization.
Laser engraving has no contact with the surface of the material, is not affected by mechanical movement, the surface is not deformed, and generally does not need to be fixed. Unaffected by the elasticity and flexibility of the material, it is convenient for processing soft materials. CNC stands for Computer Numerical Control and is an automated machine equipped with a programmed control system. The control system allows for the logical processing of programs with control codes or other symbolic instructions, which are decoded so that the machine can move machine parts. A CNC engraving machine is a powerful tool that accomplishes engraving by means of a CNC machine control.
CNC engraving machines and laser engraving machines are both computerized engraving machines, CNC engraving machines refer to CNC routers, CNC hollowing machines, CNC engraving machines or CNC engraving machines, laser engraving machines refer to laser engraving machines, both require a computer to control the engraving. A pre-prepared image file or path map is imported into the machine via computer layout. From this perspective, both are machines. Although both use CNC systems, they work differently and their mechanical construction is different. In comparison, CNC engraving machines are relatively simple in structure. Controlled by a computer numerical control system, the machine automatically selects the appropriate cutter head & tool to engrave along the X, Y, and Z axes of the machine.
The difference between CNC and laser engraving is that CNC machines use a rotating spindle with an end mill attachment that digs into the material to produce the desired engraving, whereas laser engraving machines use a high-energy laser to heat and vaporize the surface of the material to produce the engraving.
Differences in methods
CNC (Computer Numerical Control) engraving is a direct contact process. It is a CNC manufacturing process in which material is removed by a cutting tool connected to a high-speed motorized spindle. The high-speed rotating cutting tool is inserted into the material and its movement is guided by a computer system to create the desired engraving.
Laser engraving machines use a laser, which alters the material by means of high temperatures. Thus, similar to combustion, different materials produce different combustion chemical reactions during the working process, depending on the melting point of the material. Cutting results vary and fumes and odors can be produced during the industrial process. A CNC router relies on a spindle and bit to work, similar to a drill, it will only generate a lot of dust during the process, but no fumes or odors. Laser engraving is a non-contact etching, which protects the surface of the material being engraved from being scratched. In addition, the laser beam is very fine, so the gaps are small and suitable for precision cutting.
Accuracy differences
Standard CNC machines can provide accuracies of approximately 0.001″ to 0.005″, while specialized processes like polishing can provide repeatable accuracies of 0.00005″. Typically, desktop laser engraving machines offer an accuracy of approximately 0.001″, while industrial-grade laser machines can achieve an accuracy of 0.00005″. Laser engravers can create high-resolution engravings with contrasting areas of dark and light color. They are therefore suitable for engraving photographs and other similar applications where variable contrast is required. CNC machines, on the other hand, cannot produce variable contrast in engraving, but they are ideal for deep engraving (3D engraving).
Principle differences
Laser engraving machines emit a laser from a laser, which is focused by an optical path system into a high-power density laser beam. The laser beam is directed at the surface of the workpiece, causing it to reach its melting or boiling point. At the same time, a high-pressure gas coaxial to the beam blows away the molten or vaporized metal. As the beam and the workpiece move relative to each other, the material will eventually form a cut mark for engraving purposes.
The CNC engraving machine relies on a high-speed rotating engraving head driven by an electric spindle. By means of a tool configured according to the material to be processed, the processing material fixed to the worktable is cut. Through automatic engraving operations, various 2D or 3D designs of embossed graphics or text in the computer can be realized.
The biggest difference between laser engraving machines and CNC engraving machines is that the tools of laser engraving machines are a whole set of optical components, while the tools of CNC engraving machines are bits of various entities. A laser etching machine uses the high energy of the laser to complete the cutting or engraving of the material, while a CNC engraving machine uses a high-speed rotating bit to cut and engrave the material, so the two forms work differently on the engraved object.
Difference of tools
The common tools used in CNC engraving machines are jigs, drills, end mills, face mills, reamers, gear mills, hollow mills, thread mills, plate mills, and flying cutters.
While in laser engraving machines, laser modules are the only tools used for different applications. These modules are available in different operating wavelengths and power ratings. The wavelength of the laser module generally depends on the type of laser used. CO2 lasers with a wavelength of 10,600 nm are ideal for engraving non-metals.
while fiber lasers with a wavelength (of 1060 nm) are ideal for engraving metals. On the other hand, diode lasers with wavelengths of 550 nm-950 nm can be used to engrave metals and non-metals, but their low power is not suitable for vaporizing hard metals. Despite their differences, machines such as the Snapmaker 2.0 offer the ability to exchange cutting tools, both as a CNC milling machine and as a laser cutting machine.
Differences in applications
CNC engraving is used for rapid prototyping, precision engraving, deep engraving, and cutting machine parts. It can be used on virtually all materials, from metals such as aluminum, brass, silver, and titanium to non-metals such as acrylic, wood, plastic, and foam.
Laser engraving has applications in engraving medals, trophies, bar codes/QR on machine parts, electronic devices, medical devices, logos, and badges
High power lasers can be used to produce deep engraving on a variety of metals and non-metals.
Fiber lasers can also be used to produce color laser engraving on metals such as stainless steel, titanium, and aluminum. CNC engraving offers relatively greater material flexibility compared to laser engraving. Changing tools as needed makes it possible to engrave virtually any material on a CNC machine. In contrast, in laser engraving, one engraving machine cannot be used to engrave different materials. Therefore, the laser machine should be selected based on the material to be processed. Because of the accuracy and repeatability offered by CNC machines, they are used in many industries such as aerospace, automotive, defense, healthcare, and oil and gas.
Finally
Both CNC and laser engraving machines have their advantages and disadvantages. Both are advanced technologies capable of producing results far superior to traditional engraving techniques.
CNC machines offer more freedom than laser engraving machines. They can also work on a wider range of materials by adjusting the type of cutting tool. In the case of laser engraving machines, one laser engraving machine cannot be used to process all types of materials, so it is important to determine your requirements before purchasing a laser engraving machine. Overall, CNC engraving machines are ideal for engraving applications that require variable depth, such as 3D engraving, while laser engraving machines are ideal for engraving applications that involve high resolution and complex patterns.