The use of laser technology in the processing of materials began just fifteen or twenty years ago, and in the category of relative mass availability, it has generally passed recently.
As the price of CNC laser engraving machines decreased, they covered an increasing consumer market, gradually penetrating not only medium-sized enterprises, but also small companies and workshops.
Today, a laser cutter or engraver can be purchased even for personal use or even be assembled from purchased components.
Advantages of laser equipment
What is so good laser machine that the popularity of it is far surpassed even a multifunctional cutter? Not to bore a long list of advantages of a couple of dozen points, we will focus only on the key:
- speed — the maximum rate of movement of the laser beam is 500 mm/s (cutting) and 700 mm/s (engraving). None of the other types of machines can achieve such processing speed parameters;
- precision– laser equipment is included in the group of precision devices, which means that its accuracy is as close as possible to the specified values. Deviations in the positioning of the beam on the plane are literally ±0.01 mm, which allows the use of the laser in machine tools, robotics and rocket and space industry;
- quality– the diameter of the laser is on average 0.03 mm (from 0.01 to 0.07 mm depending on the focusing lens), so with these parameters it is able to create the finest cuts and holes and with maximum detail to reproduce the most complex contours of workpieces or engraving images. In the same point it is necessary to note such feature of the laser as the absence of physical influence on materials owing to what after its passing on a surface there are no damages or defects demanding postprocessing. The cut looks absolutely smooth and has a clear outline;
- cost-effectiveness-in relation to laser equipment, this item has several meanings at once. First, the cost of purchasing various tools for each operation is reduced – the laser drills, cuts, and engraves. Secondly, there is no need to purchase devices for fixing workpieces and materials – the beam is thermal, not physical, so it does not shift the objects of work. Third, the width of the laser cut does not exceed the thickness of the hair, so the workpiece on the material can be placed closely, without gaps, and with proper placement it is easy to achieve almost one hundred percent absence of waste.
Scope of CNC laser machine use
CNC laser equipment is versatile and able to cut MDF plywood and other wood surfaces, plexiglass and other plastics (excluding PVC), rubber, leather, corrugated and plain cardboard, fabrics and non-woven materials, fur, metals (fiber lasers) and others. This extensive list explains the fact that laser cutting machines have found their application literally in all manufacturing industries, from the manufacture of matchboxes to the production of aircraft.
As in the case of listing the advantages of the laser, it is impossible to tell about each area of its application, so many of them. Therefore, the most interesting and popular ones will be highlighted below.
- Cutting plywood– using the capabilities of a laser beam, a lot of useful things are cut out of plywood. These are jewel boxes, gift boxes, construction kits for children and adults, indexes and signs on the door, wardrobe numbers, figures for interior decor, letters and numbers for making holiday inscriptions and much more. A distinctive feature of the laser effect on plywood is the darkening of the cut (light charring), which gives the products a contour and decorates them.
- Metal cutting – metal is not only pipes and gears, it is also an amazing beauty of openwork products that are cut with a fiber laser on a metal sheet. The resulting butterflies, elegant female figurines, silhouettes of animals and other things become a decoration of the shelves in the interior. A separate area of work with metal sheet was the creation of weathervanes, patterned overlays on mailboxes, author’s numbers of houses and apartments, etc.
- Handmade – to create crafts mostly miniature household laser devices are used that, because of their compact size can be used at home. Despite the small size, these devices are not inferior to the quality of cutting industrial counterparts, the difference is observed only in the power of the device and the speed of operation. However, for the manufacture of piece or small-scale products, they are quite enough. Laser cuts jewelry of leather, toys, snowflakes, letters and numbers of felt, makes cards and invitations for holidays of paper and cardboard, stands for jewelry of plexiglass, etc.
- Engraving – drawings, inscriptions, patterns and even photos in high resolution, applied by a laser beam on the surface of products, differ in maximum detail, clarity and full compliance with the original image, so this engraving is rightly considered the best. It is decorated with gifts and memorabilia, as well as various corporate attributes, signs, etc. Watches, lighters, jewelry and costume jewelry, marble stands for office, leather goods can be presented as gifts.
- Perforating – we have already mentioned the fact that the laser beam is a multifunctional tool and can not only burn the surface layer of materials and cut them into parts, but also create through holes in them. Laser perforation is used in the manufacture of circuit boards for electrical engineering, production of watch mechanisms, but the main direction is the decoration of shoes, clothing, leather goods and handmade items.
Operating principle of laser engraving machine
An engraving machine is a device that significantly speeds up and simplifies the process of applying an image to the surface of the product. This method of decorating and identifying things has been used since ancient times. The first tools for engraving date back almost to the Stone Age.
In those days, as well as many centuries later, skilled engravers reproduced patterns, inscriptions and pictures by hand, working for weeks and months on particularly intricate images.
Looking at weapons, armor, snuff boxes and many other products of past centuries, decorated with engraving, you come to admire the elegance of lines and complexity of contours. You also understand something else: an accidental shift of the product in the process of work, a trembling hand, too deep pressure and other errors often led to irreversible consequences, forcing the carver to start all over again.
The work of engravers was somewhat simplified only in the last century, when they came to the aid of technical progress and brought a manual power tool with it. Small drills with motors and various interchangeable attachments took over some of the work and accelerated the entire engraving process. The most famous manufacturer of such equipment was Dremel, a company founded in America in 1932. Over time, it suffered the fate of a copier and a diaper, that is, Dremel is now called any manual machines that run on electricity, which are able to drill, engrave and grind small products.
However, despite the fact that with the advent of electric gravers business began to move faster, the problems of the human factor have not disappeared: masters still had to work, you can say, manually, now only having a drill in the hands, not a tool made of metal. Accordingly, critical and non-critical flaws still occurred periodically even when using the technique.
A real breakthrough in the work of engravers was the appearance of computer-controlled milling equipment. Small desktop machines took over the entire volume of work and performed it much faster and better. The number of errors and inaccuracies was reduced to a minimum, it was possible to put the manufacture of products on the flow, since the CNC router could work not only quickly, but also apply a completely identical engraving over and over again, following the trajectory laid down in the program.
CNC milling engraving machines show a very high quality of work, but the degree of detail of images and the speed of their application are inferior to laser devices.
However, such equipment still has shortcomings, which, however, does not prevent it from still being in demand. First of all, we are talking about the fact that no matter how thin and sharp the cutter may be, it cannot perfectly accurately recreate all the nuances and contours of complex images. The error in the work of the milling engraver is about 0.5 mm, so it is impossible to reproduce miniature drawings or small inscriptions with its help.
And here comes the laser machine – a device with software control, which still belongs to the category of new technologies, and the period of its more or less mass use is literally 5-10 years. The diameter of the laser beam is so small that the width of the slots between the parts or holes created by it often does not exceed the thickness of a human hair. And this is only the beginning of a huge list of advantages of laser technology, and one of the advantages can be called the lack of disadvantages. With some stretch, the only drawback may be still not very budget cost of such devices. Nevertheless, even in home workshops, miniature laser machines have ceased to be a curiosity.
The quality of laser engraving is so perfect that it is used even for making stamps and seals
Advantages of laser engraving devices
Engraving machines that use a laser beam in their work instead of a metal cutting tool, in all respects leave far behind their competitors in the craft. The main arguments for this statement are the following:
- very high engraving speed, up to 700 mm/s;
- incomparably higher quality of the finished image, due to the thinness of the beam and the precision of its positioning (deviations from the specified coordinates range from ± 0.01 mm);
- unlimited engraving life, which means that the contours of the drawing will not lose their clarity with heavy use, even after many years (we are talking, for example, about watches or lighters);
- wide range of materials available for decoration;
- computer control of the entire process saves time and completely eliminates errors that can be made by a person;
- due to the fact that laser engraving is applied by non-contact method, the products do not need to be fixed, that, firstly, saves money on the purchase of fasteners, and, secondly, does not damage the surface of the material;
- high level of detailing when applying small images or those that have a large number of small elements;
- perfectly smooth edges and walls of the image after a single pass of the beam. There is no need for additional post-processing, there are no small cavities characteristic of the cutter and other metal tools;
- the laser has no physical effect on the materials, so it can safely engrave even fragile, prone to chipping and cracking materials, such as glass;
- no need to buy a large number of tools;
- low noise and dust generation.
Operating principle of laser engraving machine
Due to the fact that laser engraving machines are automated equipment, that is, all processes are controlled by a computer (external or built-in elements), the work of such devices begins with the creation of a control program for them.
Optical fiber laser engraver for metal in operation
A sketch of the future image is drawn in a graphic editor, after which a file is created in the CAM-system on its basis, in which all the stages of passing the laser beam for image reproduction, etc. are registered. This file is called the control program, which specifies the starting point of engraving, the speed of movement of the tool, the depth of its immersion in the material, and so on. The program is run on a computer connected to the engraver or saved to a flash card, which is then inserted directly into the machine.
The laser equipment itself can be fiber-optic, designed for engraving metals, or carbon dioxide, suitable for working with any other materials (plastic, wood, rubber, cloth, cardboard, etc.).
In a fiber engraver, a beam is created by activating quartz doped with a rare earth coating by pumping from diode lamps. The quartz core is enclosed in a shell of optical fiber, closed from the outside by a flexible and dense plastic or other body. After switching on the pumping sources in the fiber cable, the generation of laser particles begins, some of which go out on one of the sides.
The CO-2 engraver is based on a sealed glass flask, a mixture of several gases is injected under pressure into which, that are prone to ionization under the influence of electrical impulses. The discharges come inside from the ignition unit connected to the tube and activate the gas medium that begins the process of laser formation.
The laser stream coming out of the optical fiber or gas tube falls on the focusing lens (in the case of a CO-2 emitter, it first passes through an optical system of three reflecting mirrors), which narrows it to the required parameters, turning it into a light spot on the surface of the material. Due to the small diameter, the concentration of temperature and radiation power at the cutting point is very high, so the beam burns the surface layer of the material to a specified depth in a fraction of a second. Moving at high speed, it recreates the desired image on the products step by step.