As laser engraving technology continues to advance, so have the options that are available in laser engraving machines. In fact, there are so many laser engraving systems available on the market today that it can be a bit nerve-racking, to say the least, when it comes to choosing the right system for your business. On the other hand, because there are so many options, the likelihood of finding a quality system that fits your budget and meets your production expectations is outstanding. Each year, EJ publishes the Buyer’s Guide for Laser Engraving Machines designed to accomplish just that: assist you in finding a laser engraving system that will help you build a successful laser engraving business. Each year, we show you the latest and greatest in laser engraving equipment to help you make an educated decision when it comes time to buy a laser, whether you’re purchasing your very first system or just looking to add to your existing fleet. Since last year, several manufacturers have added new, innovative features to their systems to make laser engraving even easier and more productive. For example, Xenetech Global, Inc., Baton Rouge, LA, recently introduced several sophisticated features, including one which automatically sends an E-mail to someone (a shop foreman, customer, etc.) informing them that a job is queued up to run, has finished running, job statistics, etc. Another feature provides the ability to use an LCD touch screen on the laser machine to browse through the jobs stored on the computer and control jobs during engraving, including automatic focusing, on-the-fly power, speed adjustments, etc. Some manufacturers have added new hardware options since our last Buyer’s Guide. For example, GCC America, Walnut, CA, has introduced a “knife-shaped” cutting table that features adjustable bars that allow you to create different levels when cutting completely through materials. Still other manufacturers have introduced entirely new systems. Epilog Laser, Golden, CO, recently launched the Zing Laser which, according to the company, is the industry’s first high-quality, 25 watt, entry level machine for under $8,000. “A machine of this caliber and at this price point has not been seen on the market before,” says Mike Dean, Epilog’s director of sales and marketing. “We have successfully designed and built a high-quality, entry level machine with capabilities that were previously unheard of.” The Zing Laser includes a variety of features such as 1000 dpi engraving, a laser dashboard that allows printing directly from many Windows-based software programs and an air-cooled metal laser tube. As in the past, the 2008 Laser Buyer’s Guide includes the main features and specifications for all of the major laser engraving systems available in the industry in convenient chart format. These charts can be accessed on EJ’s website at www.engraversjournal.com. There you will see all of the charts that are referenced here in this article detailing all of the laser systems and their specifications. The charts are organized alphabetically by manufacturer name, followed by the name of the laser engraving system. Keep in mind that space prohibits listing every available feature and option for every system, but the primary ones have been included. Note, too, that the information listed in the charts was provided by the manufacturers. The information presented in the charts is essentially hardware based, i.e. system specifications, engraving capabilities and optional accessories. For information on software designed specifically for laser engraving, refer to EJ’s 2008 Buyer’s Guide for Laser Engraving Software (Jan. 2008). General Specifications (View General Specifications chart online at www.engraversjournal.com/charts08) This chart provides basic information about each laser engraving system, including prices and warranty details. Note that the prices listed for the systems are general guidelines designed to give you an idea of how much a system costs. Prices will vary depending on the exact setup, features and options ordered, area of the world you are located in, etc. Because of this, most manufacturers have listed a price range and/or a general starting price to give you a ballpark idea of system prices. You will need to check with the manufacturer for more specific pricing. The Standard Components column in the General Specifications chart lists the major components supplied with the system. Many manufacturers include driver software with the purchase of a laser and some are even offering layout software, a computer and some accessories as part of the package. Lasers requiring liquid cooling (typically lasers with 50 watts of power or more) may or may not include the cooling unit (listed as “chiller” in the chart). Because there is a relatively broad selection of laser engraving machines included in this Buyer’s Guide, we’ve included the Laser Type and Major Applications (Apps.) categories to give you an idea of what the particular machine is designed to do. The Laser Type category details a physical description of the system. For example, the laser system might be a freestanding unit, an enclosed laser or a smaller desktop machine that can fit on your desk or workbench. The Major Apps. column in the General Specifications chart provides an idea of the type of work, or application, the laser is best suited for. For instance, some systems are well-suited for general engraving, e.g. awards and signs, while others are more suited for industrial marking, marking on metal or rubber stamp production. The final column in this chart lists some of the major available options like chillers, odor reduction units and cutting tables. Note, however, that most manufacturers offer a variety of other options as well (contact the manufacturer directly). Also, some options such as dual-head capabilities, air-assist packages and spotting beams are listed in different charts in this guide. Software Specifications (View Software Specifications chart online at www.engraversjournal.com/charts08) As you can see from the online Software chart, the vast majority of laser engraving systems are driven by a PC with the Windows operating system. Some systems can also be used with a Macintosh as the host computer. Software programs that can be used to drive each of the systems in this guide are listed in the Software Specifications chart. A few manufacturers offer proprietary software, i.e. software designed exclusively for that system or, more commonly today, developed by that particular company. Many laser manufacturers that also develop computerized engraving machines offer proprietary layout software that can be used with both types of equipment (or slightly modified versions of the software, i.e. one version for lasers and one for mechanical engravers). Very few systems run exclusively on proprietary software, and those that do usually allow you to import text and graphics from other software. As we’ve seen with computerized engraving machines, most laser manufacturers are opting for the open architecture approach, which means they are designing their systems to work with a variety of popular third-party graphics and CAD software programs such as CorelDRAW and AutoCAD. (As mentioned earlier, see our 2008 Buyer’s Guide For Laser Engraving Software (Jan. 2008) for more information about laser engraving software packages.) Laser Unit Specifications (View Laser Unit Specifications chart online at www.engraversjournal.com/charts08) The next chart details some of the hardware characteristics of the various laser engraving units. A laser produces extremely intense rays of light. To engrave, the beam is focused through a special lens to a pinpoint-sized spot. The focused beam is so intense that it vaporizes portions of the material, leaving an engraved image or, in some cases, cutting completely through the material. The first column in the Laser Unit Specifications chart describes the type of laser used in each system. Lasers are named for the material from which their light is generated. For engraving applications, the most common types of lasers include CO2 and YAG lasers. A CO2 laser works by exciting the molecules of a carbon dioxide gas mixture (usually including nitrogen and helium). This type of laser produces long-wave infrared light, which is well-suited for engraving and cutting many nonmetal materials such as wood, plastic, glass, ceramic, leather, solid surface material, etc. In general, CO2 lasers work well for cutting materials that are poor conductors of heat and electricity. Bare metal and other reflective surfaces do not absorb the light generated by CO2 lasers as well as they do the light created by YAG lasers. For this reason, most CO2 lasers cannot engrave bare metal, although they can successfully engrave through coatings on metal, e.g. enameled brass and anodized aluminum, or metal treated with a special chemical. |
||||||
|
||||||
YAG lasers do not use gas to operate. Instead, light is generated utilizing a solid crystal or rod of Yttrium Aluminum Garnet along with a small amount of Neodymium (Nd), a rare earth element. Hence, these lasers are frequently referred to as Nd:YAG lasers. YAG lasers are suitable for engraving a wide variety of nonmetal materials as well as bare metals, including a lot of “unmachinable” substrates such as very tough/hard grades of stainless steel. If you’re considering purchasing a YAG laser, be aware that there are different kinds. For example, one type of YAG laser incorporates a “flash lamp” device, i.e. a 10,000-watt light bulb, which excites the crystal material to create the laser light. A variation on this type of YAG laser is a “diode-pumped” laser in which the light bulb is replaced with a solid state diode laser like those found in CD-ROM players, which pumps the rod to generate laser light. Although they’re more expensive, diode lasers run more efficiently than light bulb lasers by decreasing power consumption and outputting less heat. Conventional YAG lasers output great amounts of heat and need to be water-cooled, whereas diode lasers can be air cooled. In addition, diode lasers provide longer operating times before it becomes necessary to replace them (diode vs. light bulb). Diode YAG lasers are usually designed for specific applications. For instance, these lasers are often used for making and marking electronic products and for producing large quantities of parts over long periods of time. These types of lasers can be set up in a production environment to basically work on their own. Another type of laser is the Nd:YVO4 (Yttrium Vanadate) laser, which was developed to eliminate some of the problems associated with traditional CO2 and Nd:YAG lasers. The type of crystal used in this laser, while not as powerful (wattage-wise) as a YAG crystal, operates more efficiently and produces higher “peak power” (the portion of the laser’s energy output that is used to engrave). In other words, the beam is so tightly focused that its spot size is minuscule (as small as .00098"). The result is a low-wattage laser that produces extremely high-resolution and greater cutting power than many higher- wattage machines. Some manufacturers also offer the option of “hybrid” lasers that, for example, combine both CO2 and Nd:YAG technology. Combination lasers like this increase the range of materials that can be processed with one piece of equipment. Laser marking, cutting and engraving can all be performed using a single source and, better yet, a single investment. Trotec Laser, Ypsilanti, MI, has recently introduced the FineMarker Hybrid that merges the technologies of CO2 and YVO4 wave length laser machines into a single, multifunctional system. According to the company, combining these two laser sources increases the range of materials that can be processed with one laser machine. Yet another type of laser continuing to make its mark in the industry is the newer “fiber” laser. Fiber lasers use fiber optics to generate and deliver the laser beam instead of the traditional hard optics and beam delivery method. These lasers can be air cooled, which means no separate chiller is required. They also use up to 50 percent less power and have a longer life over traditional YAG and CO2 lasers. Fiber lasers require no maintenance and no consumables such as diode packs and lamps, which lower operating costs. In addition, they have a smaller footprint, making them more portable. Fiber lasers also have an extremely small spot size with a more concentric beam that allows for higher-resolution and microscopic marking. The next column in the chart provides the power requirements for each system, followed by a column labeled Engraving Unit Size which indicates the physical size of the unit. This gives you an idea of how much space the laser engraving unit occupies. The laser class is also included in this chart. Lasers are rated by the Center for Devices and Radiological Health (CDRH), Food and Drug Administration (FDA) on a scale of 1 to 4. A rating of 1 indicates the safest type of laser. These systems are typically designed so that the laser beam delivery section is enclosed in a cabinet and a safety interlock mechanism will automatically turn the laser off if the cabinet door is opened during operation. A class 4 laser usually means that the laser beam is not enclosed and, therefore, requires a protective operating environment, e.g. enclosures and equipment to protect the operator. A “3a” laser class rating was introduced as a result of an added feature called a “spotting beam,” “indicator beam,” “red dot pointer,” etc. This feature allows you to position a “red dot” laser beam over the work to display X,Y coordinates, verify workpiece placement or to run the machine with the cabinet open to see the path of engraving. The class rating of 3a requires extra safety precautions when using this feature. As shown in the same chart, many manufacturers offer an exhaust system either as part of the standard equipment or as an option that can be purchased for an additional cost. Others require that you purchase a system (or part of a system) from another source, e.g. a heating/cooling contractor. Laser Specifications (View Laser Specifications chart online at www.engraversjournal.com/charts08) The next chart includes features directly related to the laser beam. The beam is the actual cutting tool, so naturally this is an important part of any laser engraving machine. The first column in the chart, Beam Power, indicates the power or intensity of the laser’s beam, a very important feature of laser engravers. The intensity of the laser beam is commonly expressed in terms of wattage (per square centimeter). Generally speaking, the higher the wattage the more powerful the laser beam and, in simple terms, more power means the laser can engrave faster and/or deeper in a given amount of time. Keep in mind, however, that how fast/deep a laser can engrave depends on other factors, including the material being engraved. The laser wattage listed in the Beam Power category indicates the minimum-rated wattage guaranteed by the laser manufacturer. Laser tubes can vary in the amount of wattage they actually output. A laser rated at 25-watts, for example, might actually output 30-32 watts or even as much as 40 watts. Actual wattage will vary from one laser tube to the next from the same manufacturer. In other words, if you purchase a 25-watt laser, you will probably receive a laser with slightly more power. In this case, the 25 watt rating is merely the minimum-output level guaranteed by the manufacturer. Note, too, that the power of a laser is also dependent on the type of laser (mentioned in the Laser Unit Specifications chart). For example, the light coming from a diode-based YAG laser is approximately 10 times more efficient than the light coming from a YAG with a flash lamp or a thermal light bulb. And a fiber laser can be up to 50 percent more efficient than a Nd:YAG or CO2 laser. It is possible for a 12-watt diode laser to mark faster than a 120-watt flash lamp laser because the diode laser has higher-energy density at the workpiece. Today, most manufacturers offer the ability to upgrade a system’s power without having to purchase an entirely new system (noted by Wattage Upgrades in the online chart). On some machines, changing to a higher-wattage laser can be as simple as loosening a few screws and replacing the fully modular laser unit. You can either do this yourself or, if required, send your equipment to the factory for the upgrade (the chart lists these options). The ability to upgrade your laser greatly increases the versatility of the machine and can be a fantastic benefit. For instance, some engravers initially purchase low-powered lasers to save money and/or because they don’t need a lot of power for the kinds of jobs they’re doing when they first start out. If, however, down the line they find that they want or need more power, an upgrade is much easier and less expensive than replacing the entire machine. Beam Motion, the next listing in the chart, describes the way the laser beam moves while engraving an image. Vector movement on laser systems is the same as the table and spindle movements found on most computerized engraving machines, i.e. simultaneous X,Y movement creating a “cutter path” capable of following a shape. Vector engraving is extremely efficient for engraving certain images such as a border around a plaque or character outlines. Additionally, vector motion is necessary in order to do any cutting/profiling with the laser. Because this type of laser is capable of simultaneous X,Y movement, borders and outlines are engraved in one continuous motion. Raster motion describes a back-and-forth movement of the laser head during engraving. In this mode, the laser beam carriage typically moves from the top to the bottom of the work area while the beam oscillates left to right, i.e. it is a back-and-forth scanning motion starting at the top of the item and moving toward the bottom. As the beam moves from left to right, it is turned on and off to engrave the image. Raster scanning is very similar in concept to how the picture is formed on a black-and-white television set, where a series of lines are drawn on the screen that collectively form the picture. Today, unlike a few years ago, all of the systems that use this type of beam motion are capable of both vector and raster engraving capabilities. A third type of laser beam motion is one that utilizes a galvanometer. With conventional lasers, the motion control system typically consists of a belt/rail that moves a small lens over the material to be engraved. There are no “galvo” lasers listed in this year’s Buyer’s Guide, but it’s nice to know what’s available, especially since galvanometer lasers are very fast and they are widely used for industrial marking. With galvanometer-based systems, however, the laser beam is directed at small mirrors, which are controlled by the galvanometers. As voltage is applied to the galvanometer, the mirrors swivel and tilt in order to direct the beam to the material surface and reproduce the image. As a simple analogy, imagine holding a mirror and reflecting sunlight off of the mirror onto a wall, then swiveling your wrist, allowing you to “draw” a character on the wall with light. A laser with a galvanometer works in a similar manner. As mentioned, a major advantage of galvanometer-based lasers is speed; essentially, they are “lightning fast.” Galvanometer lasers support both vector and raster engraving, so you can achieve the same type of engraving in less time. Industry estimates put vector engraving with a galvanometer laser at 75 to 100 times faster than vector engraving with conventional motion technology and raster engraving at least 2 times faster. What’s interesting about raster engraving with this technology is that instead of scanning across an entire piece of material, engraving small pieces of each image, a laser with galvanometer motion control will actually engrave images separately, eliminating unnecessary motion. |
||||||
|
||||||
Another advantage of this technology is that it requires almost no maintenance. Conventional laser motion works with pulleys, bearings, belts, etc., that need to be maintained and periodically replaced, whereas a galvanometer system basically has no maintenance except for the lens. Some disadvantages to galvanometer-based lasers is that they cost more than conventional lasers and they have a relatively small maximum working area (area that can be engraved in one setup) of about 8" x 8". In addition to wattage, another factor determining the power of a laser is the spot size of the beam. As described earlier, a laser beam is typically focused and concentrated to a pinpoint size through a special lens, which determines how much light is present in a specific area. For example, 40 watts of light distributed over a .002" diameter spot has substantially higher energy density (power) than 40 watts of light distributed over a .006" area. Most manufacturers offer interchangeable lenses for their equipment, enabling you to vary the spot size from around .003" on up, as shown in the chart under Standard Lenses. Typically, you receive one type of lens with the laser and others are optional. (Note that some manufacturers have described their lenses in terms of focal length, nominally the distance from the lens to the material being engraved, e.g. 1.5", 2", etc.) In addition to affecting the laser’s energy density, the ability to vary the spot size of the beam is analogous to using different cutter tip sizes in rotary engraving. Smaller beam sizes provide the ability to achieve intricate detail such as very small type, e.g. 5 point type, rubber stamps and halftone photographs. On the other hand, larger spot sizes enable the machine to rout out large image areas more quickly since fewer cutting passes are needed. Several manufacturers have introduced Special Lenses, including high-resolution lenses and lenses for engraving uncoated metal with a CO2 laser. High-resolution lenses typically focus the lens to an extremely small, consistently-shaped spot, resulting in extremely detailed engravings. The “uncoated metal” lens refers to a new lens developed by manufacturers to allow a CO2 laser to mark uncoated metal for applications such as UID marking. The optic system is an area in the laser engraving industry where we continue to see improvements. For instance, Epilog introduced its new Radiance Optics feature this year as a standard feature on several of its systems. This new optics system, according to Epilog, produces a smaller spot size and a rounder, more consistent beam for better engraving and cutting across the entire work area. It also produces a higher-power density which allows users to mark on some bare metals. Before purchasing a new laser engraving machine, one characteristic you may want to consider is how you focus the laser prior to engraving. Focusing involves positioning the lens at a specified distance (focal length) away from the material surface to be engraved. The distance will vary with the focal length and the spot size of the lens you are using. On most units, focusing is accomplished by adjusting the table position with the help of a motorized height adjustment (“manual” in the chart), a feature which automates the table movements and allows you to quickly adjust the table position. Today, most units also offer the option of automatically focusing the lens as a standard feature. Automatic focusing usually incorporates a sensor-type mechanism that will “sense” the correct focusing distance. (Others may require that you enter a material thickness into the software.) All you have to do is place the material on the worktable, and the machine automatically positions the table so that the work piece is the correct distance beneath the lens. This feature is very convenient and can be a real time saver. Another time-saving feature, at least for some jobs, is a Beam Splitter. Many manufacturers are now offering optional dual-head capabilities that will split the laser beam in two, allowing you to engrave two identical pieces simultaneously. For example, on a 100-watt machine you can use the dual-head option to create two 50-watt beams. If you have a large order for identical or nearly identical items, this feature can be a great production-booster since you can use one laser to engrave two items at once. Laser Engraving Specifications (View Laser Engraving Specifications chart online at www. engraversjournal.com/charts08) The Laser Engraving Specifications chart is an important one to study in order to determine the types of work the machine can accommodate. After all, you want a machine that is capable of engraving the size, shape and kind of work that you will be doing. The Worktable Size column describes the physical size of the machine’s worktable. The Working Range column indicates the maximum size area that the laser can engrave in one setup, and the Max. Part Size column lists the dimensions of the largest item that can be held in the engraving machine. Engraving speed, as shown in the next column, is typically expressed in inches per second (ips). Note that this is straight-line engraving speed. Used in conjunction with appropriate software, lasers are also capable of generating images at different resolutions, as indicated in the chart under Resolution (dpi). Resolution is typically defined in dots per inch (dpi) and signifies the amount of detail achievable; a higher resolution means finer detail. However, resolution is also directly related to the amount of time it takes to engrave an image; the higher the resolution, the more time it takes. In general, the ability to select the resolution you want for a particular job can be an advantage, especially for applications such as engraving halftone photographs, as it provides you with more flexibility when it comes to time vs. detail. As shown in the next feature in the Laser Engraving Specifications chart, many manufacturers offer a cylindrical engraving fixture for engraving on round and tubular shaped items such as wine glasses, vases, pens, etc. In most cases, these units are optional accessories. Air Assist is becoming more prominent in laser engraving, and several suppliers now offer it as a standard equipment feature. An air assist setup directs a stream of pressurized air or gas onto the engraving surface to reduce flaming and burning; it also protects the lens and other optics from damage. (Note that this feature typically requires a separate air pump which may or may not be included.) Cutting tables and vacuum tables are also available for many laser engraving systems. Cutting tables typically consist of an open honeycomb-type grid that, when placed on the worktable, allows the laser beam to pass through the material and allows air to flow beneath it as the material is cut. Profiling on a cutting table creates cleaner cuts and better edge finishes with less melting and burning, which are common problems when profiling certain materials. Vacuum tables have been used in computerized engraving for years and there are some applications for them in laser engraving as well. These tables use suction to keep flimsy items such as fabric, paper and ultra-thin engraving materials flat during lasering to produce more accurate engraving and cutting. Vacuum tables are usually considered as separate accessories, although they have been integrated into some laser systems. Pass-Thru Table is a new feature added to the Laser Engraving Specifications chart. Many manufacturers are making their systems more versatile by incorporating this option, typically in the form of access doors, e.g. retractable doors on the top or sides of the system. This feature allows you to engrave large and oddly-shaped items that otherwise would not fit in the engraving machine. Laser Marking Features (View Laser Marking Features chart online at www.engraversjournal.com/charts08) The final chart in this Guide describes each system’s Laser Marking Features. These are typically operator-definable features that allow you more control over the laser engraving process. As shown in the chart, many of the computer-controlled lasers have a feature known as Proportional Power. This control automatically changes the power of the laser beam by linking the laser’s pulses with the speed of engraving. For example, in vector mode the laser operates at full speed when engraving straight lines, but slows down when cutting a curve. Without proportional power, the result is deeper cuts when cutting curves than when cutting straight lines. The proportional power feature increases/decreases the laser power as necessary, e.g. power is decreased when engraving curves and/or increased when engraving straight lines. This feature is very useful as it can eliminate variations in depth and line widths. Raster-Only Mode is a software setting that instructs the laser to only engrave in raster mode and ignore any vector lines in the image. This is primarily used when lasering clip art. CorelDRAW clip art, for example, is known to have “hidden” vector lines in many images. If these lines are engraved as vectors, the result is usually very unattractive—the image is often distorted and, in general, it looks odd to have “stray lines” within an otherwise rastered image. As such, raster-only mode can be an advantage in these situations. Another feature associated with raster engraving is called Optimized Raster Engraving. Laser engravers with this time-saving feature will automatically optimize the engraving speed, i.e. the laser engraves in the areas where an image exists and then skips the blank spaces between image areas. This feature can substantially reduce engraving time since the laser “scans” only those areas to be engraved rather than the entire layout. Memory Buffer is a feature found on some systems that enables you to download several jobs to the engraving unit, freeing up the host computer. When several jobs have been downloaded, you can select which job(s) to engrave. With some systems, the buffer will also display information such as the selected laser power and engraving speed for the job. Most engraving units have a memory buffer for downloading jobs to the engraving machine and freeing up the computer. File Compression is a feature that will automatically “compress” the file before it is downloaded. This not only reduces the time it takes to send a job to the engraver, but it also reduces the amount of memory the file takes up in the buffer. |
||||||
|
||||||
Auto Halftones is a software feature that is typically built into the driver software and automatically generates halftone images from artwork such as photographs. In order to be laser engraved, a photograph must first be converted into a halftone (a series of various sized dots that the laser can engrave). This usually involves importing the image into a separate software package and applying a “halftone screen” to create the dots. Automatic halftoning eliminates this step by applying a halftone screen for you, based on the engraving resolution that you select. Some lasers also feature a sort of “halftoning” option known as “dithering.” Instead of applying a traditional halftone screen to a photographic image, the dithering technology applies a random dot pattern, which looks more like lines as opposed to dots, and tends to create a more realistic rendering of the photo in the final engraved image. This is an especially good feature to have on your laser if you do any type of photo engraving. Indicator/Spotting Beam, briefly mentioned earlier, is a convenient feature that allows you to visually check the position of your layout on the workpiece without actually lasering. A CO2 laser beam is invisible, but a spotting beam can be used to create a visual reference showing the exact location of the lasered mark. The feature is essentially a red indicator light that shows up on your work so that you can see where on the material the engraving will take place. It helps reduce the amount of time and materials that are wasted through trial and error. The specifics of how this feature actually works will vary among systems. For example, on one unit, you can direct the indicator beam to different areas on the workpiece and display (e.g. on a LED readout) exact X,Y coordinates; or you can put the laser through a “dry run” with the cabinet door open, causing the beam to simulate the engraving or cutting job. (The inclusion of this feature may require additional safety precautions. Check with the manufacturer for specifics on this.) Many lasers have a fixed origin, i.e. the reference position on the laser’s worktable. For instance, many lasers in this industry use the upper-left corner as the point of origin. Relocatable Origin, the next feature in the chart, is used for changing the origin position. This is helpful when you’re engraving odd or nonsquare items, e.g. where’s the upper-left corner of an obelisk? In a case like this, changing the origin to the center, for example, will greatly simplify the setup process. Similarly, Center-to-Center Positioning is a new feature added to this year’s Buyer’s Guide. This particular option allows you to change the home position of the laser to reference the center of your artwork. Typically, this is used in conjunction with the relocatable origin feature just mentioned. Center-to-center positioning provides you with additional flexibility for properly positioning text and graphics on the item to be engraved, especially oddly-shaped pieces. Auto Focus/Material Thickness is a sophisticated tool that causes the laser to continually focus during engraving (like a Z-probe/sensor on a computerized engraving machine). This prevents depth variations in uneven materials and it also allows you to engrave materials/items that are purposefully uneven in shape, e.g. a tapered glass or a bumpy surface, without changes in engraving depth. Software-Adjustable Table Height is another new feature that represents some of the innovative technology available today. This feature will automatically adjust the table height/focal distance between engraving passes, e.g. to automatically cut through thick material. Bottom-Up Engraving allows you to instruct the laser to start engraving at the bottom of the job and work toward the top. This feature was developed for engraving materials that generate excessive smoke, e.g. rubber for stamps, since it greatly reduces the amount of smoke that’s drawn over the already engraved area, ultimately saving you cleaning time. It’s also useful for lasering colored materials, such as white plastic with a bright red core, where red soot could be dragged over the white plastic causing discoloration. The last feature in the chart is 3-D Engraving. In laser engraving as in mechanical engraving, 3-D effects are accomplished by varying the depth of cut. This is achieved by raster scanning an area and then firing the laser at different power settings at each X,Y position. Greater wattage provides a greater degree of relief depth. Also, the more depth variation you have, the greater the three-dimensional effect. Many lasers with this feature allow engraving up to 256 depth levels per raster pass. The last column in this chart lists any specialized features the manufacturer chose to highlight. This is an area where the manufacturer can showcase newly added and unique features about their equipment. Contact the manufacturer directly for more information about special features. Conclusion With each Buyer’s Guide we publish, it becomes more evident that your options in laser engraving systems continues to expand, whether you’re looking for a low-cost system, a high-end unit or one that’s somewhere in between. Features are becoming more sophisticated, yet the systems remain easy to use. And it would seem that more applications are popping up everyday as laser users find more and more creative uses for their equipment. So, if you’re ready to venture into the engraving market or add to the capabilities you already have, this is a great place to start. We’ve compiled all the basic information you need in order to purchase the type of laser engraving machine to launch you into a profitable, and many even say “fun,” business opportunity!
|
