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Rotary vs. Laser: Which is Best?

Copyright © 2011 by Davis Multimedia, Int'l. All Rights Reserved.
As Printed in May 2011, Volume 36, No. 11 of The Engravers Journal

The look of rotary engraved metal is hard to beat. Photo courtesy of Vision Engraving & Routing Systems, Phoenix, AZ.


     Until the late 1970s, manual engraving machines (also known as pantograph engraving machines) were the only type of engraving equipment available in the market. This “workhorse” machine was used for engraving everything—trophy plates, pens, watches, computer keycaps, wooden signs, groundbreaking shovels and more.
     When computerized rotary engraving machines arrived on the scene, we were introduced to a whole new era in engraving. No longer did we have to insert individual pieces of brass type into a copyslide and manually trace the characters to engrave on an item. Instead, we could type in a message or import graphics directly into the computer and basically watch the machine engrave. The computerized system drastically reduced the time and labor involved in engraving a job that could take an hour or more on a pantograph to one that could be completed in minutes.
     And then came laser engraving machines, which simplified the engraving process even further. Instead of using engraving cutters, the laser used a beam of light to mark materials. The technology was nothing short of amazing. Once again, the labor and time involved in setting up jobs was significantly reduced and it was easier than ever to engrave a wide variety of materials.
     Although computerized rotary engraving machines eventually replaced pantographs for the most part (although some of you veterans may still have one in a shop corner and some of you may use it on occasion), the same cannot be said of lasers. Lasers are fantastic for all kinds of engraving applications and new technology is continually being introduced. And they are, by most accounts, the dominant marking method in the industry today.
     However, while a lot of industry attention is focused on lasers, the truth is both engraving techniques are still alive and well. Like other marking and personalization methods, such as sandblasting and sublimation, rotary and laser engraving each have unique qualities when it comes to the overall look they can achieve as well as the types of applications for which they are best suited.
     If you are new to the industry and are considering purchasing engraving equipment, or even if you are a veteran who is looking to add equipment to your shop, it’s good to know how these two marking methods compare. Here’s a review of recent developments for each of these marking methods along with the applications for which they are best suited.
Developments in Rotary Engraving
     Though perhaps not as prominent as other equipment developments, rotary engraving has had its fair share of technological advancements in recent years. The trend, for the most part, has involved attempts to make the machines easier to use than in the past. This lack of user-friendliness has been viewed as a significant detriment to rotary engraving ever since lasers arrived on the scene. There has also been a move towards enhancing machine capabilities through accessories. (For more information on this topic, read “Accessorizing Your Equipment, Part 1: Rotary Engraving,” Mar. 11.)
     For example, machinist-type high frequency spindles that run at 50,000-60,000 rpm are now available for most engraving machines. This tool allows users to use a standard rotary engraving machine for additional capabilities such as deep engraving and cutouts on materials like stainless steel, milling dies for hot stamping and more industrial cutting and detailed milling applications.



 
 
Lasers can be used for many unique applications, such as engraving rubber stamps. Photo courtesy of Gravograph, Duluth, GA.

 


        Useful features for specific applications are also becoming more prominent on rotary engraving machines. For example, an accessory is now available for many machines that can automatically insert Raster Braille spheres to create ADA-compliant Braille signs which can significantly reduce the time needed to produce them.
     One of the newer user-friendly features found on many rotary machines today is an electronic surface detection system. With this feature, the engraving cutter automatically finds the material surface and the Z-axis continually adjusts to the material surface during engraving to prevent uneven engraving depths. This is an excellent feature for engraving uneven or curved surfaces on a wide range of materials, and it helps prevent a lot of costly mistakes.
     Red laser pointers for easy setup and job preview is another recently introduced feature on many systems. Many machines have the ability to use a red pointer beam to define the engraving area of the item being engraved and automatically enter this information into the layout software, instead of awkwardly using a ruler or inserting some intuitive guesswork.  This is especially useful for items with an unusual engraving area, such as an oval shaped area on a picture frame or bracelet.
     Increased engraving speed is another significant advancement in rotary engraving. Many machines are up to three times faster than the units that were produced five or ten years ago, allowing engravers to increase productivity and earn more profits.
     In terms of time-saving features, advanced electronics and new software capabilities allow for faster and more accurate engraving, smoother motion controls and time-saving features. Software updates have also made job setup easier than ever before, again taking out some of the “mechanical measuring” and replacing it with more visual autolayout features and wizards.
Developments in Laser Engraving
     Laser engraving technology continues to develop at a fast pace and every year we see some advancements. Generally speaking, lasers today are less expensive, faster and more user friendly than they were even just a few years ago. Or, to put it another way, for about the same amount of money you can buy a laser with more power and more features—basically a machine with overall greater capabilities.
     One trend that is evident in the industry is that newer technology that was previously only available in more expensive midsize and large engraving machines is showing up on smaller models without significant increases in cost. Some examples include features such as a red dot pointer, air assist, cylindrical attachments and more choices in wattage.

   
   
  Rotary engraving machines are well suited for special applications, such as inside and outside ring engraving. Photo courtesy of Xenetech, Baton Rouge, LA.    

     In addition, several manufacturers have introduced optical recognition systems for midsized lasers, an option that was previously only available on large, expensive laser cutting systems. A major application of this feature is to accurately and precisely cut items that have been preprinted, such as sheets of screen printed or digital transfers, screen printed or embroidered labels, printed membrane switches, signs, name badges, models, decals, puzzles, cards, stationery, etc. In order to cut out items that have not been created in the graphics software, an optical recognition system uses a camera and software to optically recognize the shape to be cut. The camera targets registration marks on the material and applies the cutting data to create a vector cutting path to precisely cut out shapes.
     Several manufacturers have also introduced “pass through” options for small and midsized lasers that allow you to engrave oversize items such as golf clubs, surfboards, cabinets and a host of other items that are too large to fit within the standard engraving cabinet.
     Perhaps the most innovative technology to hit the market is the introduction of fiber and hybrid lasers designed for laser engraving. Fiber lasers produce the same wavelength of light as YAG lasers and can be used for the same applications, such as marking directly on bare metals and engineered plastics. However, fiber lasers are gaining ground on diode pumped Nd: YAG and Nd: YVO4 lasers because they are more compact, they can be air cooled and they produce the same energy at a lower cost. In addition, the laser power sources in fiber lasers last up to approximately 100,000 hours versus 10,000 hours for YAG, YV04 and CO2 systems.
     For many shops involved in laser engraving, having both CO2 and fiber laser technologies can be an advantage because each is suited for engraving on different materials. CO2 lasers can’t mark uncoated metals directly without special optics, but fiber lasers can. Fiber lasers can’t cut or mark organic materials like wood and plastic, but CO2 lasers can. As such, another notable trend is the introduction of “hybrid” lasers that combine both capabilities into a single system. These new laser systems allow processing mixed materials in one step and can be used to engrave wood, glass, metal, leather, acrylic and more.
Laser vs. Rotary
     Laser engraving machines and rotary engraving machines are similar in that they are both used to engrave a variety of materials with stunning results. However, they are also different in many ways including the mechanics of how they operate and the different “looks” that they produce. If you are new to the industry and have never seen a rotary engraving machine in action, or the engraved results this technique can produce, you owe it to yourself to check it out. And, likewise, if you have never seen a laser engraving machine in action or laser engraved products up close. EJ has published hundreds of articles on both subjects and you can also check with equipment suppliers for more information.
     When it comes to the applications that each method is best suited for, there are some areas where one method clearly outshines the other and others where either method works equally well. Following is a look at some of the applications for each of these methods.

 
Lasers are capable of engraving fine, intricate text and graphics on a variety of materials, including acrylic. Photo courtesy of Acrylic Idea Factory, Norcross, GA.   A unique application for rotary engraving is creating custom rhinestone apparel. Photo courtesy of Vision Engraving & Routing Systems.

Rotary Engraving Applications
     Metal Plates, Jewelry, Gifts, etc.—Rotary engraving has major advantages over CO2 laser systems for applications involving engraving on metal. A rotary system can engrave just about any type of machinable bare metal including aluminum, brass, stainless steel, silver, gold, pewter, titanium and platinum. It doesn’t matter if the metal is coated or uncoated, precious or semiprecious; if it is machinable, it can be engraved with a rotating cutter and even unmachinable metals of all kinds can be easily marked using a nonrotating diamond graver.
     This is one capability that a CO2 laser does not have. While a laser works very well on some coated metals, such as anodized aluminum or specially-coated black brass, producing a mark on bare metal requires the use of a special metal marking chemical (such as CerMark) that, when lasered, produces a black mark. While the results can be quite suitable for many applications, there is an additional time factor involved since the chemical must be applied, allowed to dry, engraved and then cleaned off.
     Another reason that rotary engraving is preferred for engraving metal is the look that can be achieved. It’s a fairly safe bet that when most customers buy an engraved gift or trophy, they are thinking of the classic look of engraved metal that is bright, shiny and has some depth that they can feel when they run their fingers over it. A laser system is well suited for many applications but they do produce a different look, one that resembles a black, “printed” appearance. Lasers and printing processes such as sublimation can’t really compete with rotary engraving machines when it comes to creating the traditional look and feel of engraved metal.
     Another plus on the rotary engraving side is that several manufacturers have designed equipment specifically for jewelry and gift engraving. You can choose from a wide selection of holding accessories, such as jigs designed specifically for engraving pens, watches and bangle bracelets, as well as specialized accessories like cylindrical attachments (wine glasses) or ring attachments (for engraving both the inside and outside of rings).
     Rotary engraving is exceptionally well suited for producing a spectacular look on any type of metal jewelry or engravable gift item which makes this method well suited for engraving a variety of existing merchandise. Just a small sampling includes watches, identification bracelets, metal pens, charms, 14K wedding rings, bridal cake knives, tankards, flasks, compacts, luggage tags, etc. Just about any existing metal item that your customer brings in can most likely be engraved using a rotary engraving machine provided you can find an adequate way to hold it.
     Text—Rotary engraving is admittedly not the best method for engraving detailed and complex logos, graphics or photographs. Graphic designs and photographs are most often bitmap images, meaning that they are made up of a series dots. In order to be reproduced using a rotary system, these images need to be in vector format where the image is comprised of lines and arcs. However, vector conversion can be a complicated and time-consuming process, and you may not always get the results you are looking for. Lasers are really the way to go for intricate graphics and photographs (more about this later).
     Rotary engraving is, however, a good method for engraving text-type messages. Many engravers will set up a rotary machine in the back of the shop and use it as a “workhorse” to generate quantities of tags, name badges, nameplates, trophy plates, etc. If you don’t do a lot of graphics but are involved in a lot of jobs involving text, a rotary system is a time-proven answer, particularly when the material is difficult or impossible to engrave using a laser. That list might include not only most metals but also materials such as phenolic or PVC plastic which are hazardous to laser engrave.

   

A variety of rotary engraving machines are available. The Viper GE from Xenetech was designed for gift and jewelry engraving applications.

  Braille beads are placed into an ADA sign. Photo courtesy of Vision Engraving & Routing Systems.

     ADA Signage—An area that continues to be a profit center for many engraving businesses is interior ADA signage. ADA guidelines for signage are specific and require, among other directives, that text be raised 1/32" above the sign surface and Braille dots conform to certain regulations regarding the diameter, the distance between and the height and shape of the dots. When it comes to creating signage that adheres to these specific guidelines, rotary engraving machines have a distinct advantage over lasers. With a rotary engraving machine, you can easily create raised text using a couple of different techniques. One of the most popular is to apply a 1/32" thick piece of adhesive-backed plastic engraving stock to a sign blank, cut the characters out of the attached material and remove the excess material to reveal the tactile text.
     Braille characters can also be produced in a couple of different ways using a computerized engraving machine. One method involves routing out a “window,” leaving the raised Braille dots in the recessed area. The second is to use the recessed sphere method that involves drilling holes into the material and then inserting small plastic or metal spheres into the holes leaving about half of the sphere protruding above the sign surface and functioning as a Braille dot.
     The major advantage of using a rotary engraving machine for ADA signage is that you have precise control over the depth, size and shape of the Braille holes and the raised characters of the text message. There are special cutters specifically designed for routing out a recessed area in the sign and leaving the appropriately sized and shaped Braille dots, and for drilling accurately sized holes for the Braille dots. In addition, as mentioned earlier, an inserting tool is available for rotary systems that will automatically insert the spheres after the holes have been drilled.
     Lasers do an excellent job when cutting raised characters because the laser cuts only through the appliqué material, not the substrate, and there isn’t much cleanup. On the other hand, they have a difficult time with either of the two methods for generating Braille, and you don’t have the same amount of control over the engraving depth as you do with a rotary machine.
     Rhinestone Apparel—A newer application for rotary engraving is the ability to create custom rhinestone apparel, a nice feature for shops that have diversified into personalized apparel. Using your rotary engraving machine, you can create a template for the rhinestone design and then use a heat press to apply the design to different types of fabrics to create custom apparel.
     The process involves first creating a design using a vector-based graphics program such as Adobe Illustrator or CorelDRAW, or your engraving software. Next you create a template from the design by placing drill points along the outlines where the rhinestones will be placed. Vision Engraving & Routing Systems’ (Phoenix, AZ) software has a drilling feature for doing this and Roland DGA (Irvine, CA) has special software designed specifically for this application. Using Roland’s software you can determine the placement of the drill points based on the size of rhinestones you will be using.
     Once you are satisfied with the design, you engrave the template into a piece of plastic. The engraving cutter drills the holes into the plastic template material creating the holes to hold the rhinestones. Once the design is cut, simply pour the rhinestones onto the material and use a flat, pad-style brush to sweep the stones across the template and into the holes. With the stones in place, cover the design with a piece of transfer tape. When you remove the transfer tape, the stones are removed with it. Then simply place the design on the garment and use a heat press to apply the rhinestone design.
     Although a specialized application, this example shows the versatility of rotary engraving. The ability to engrave deeper into materials broadens the applications to include techniques that are not possible on a laser engraving machine.

Rotary engraving is an excellent method for metal gift and jewelry items. Photo courtesy of Vision Engraving & Routing Systems.

Laser Engraving Applications
     Extreme Versatility—An area where lasers really shine is for unique materials and applications. Laser engraving is such a versatile marking method that the applications for which you can use it are really only limited by your imagination. The versatility (and ease of use) of a laser far outweighs that of a rotary system. For example, not only can you engrave materials such as acrylic and coated metal quickly and easily, but you can also put a pair of blue jeans in your laser cabinet and engrave a design on the pocket. Is your customer looking for a unique gift? You can use your laser to create a custom jigsaw puzzle that features a photograph or in the shape of a corporate logo out of acrylic, wood or even leather.
     Many engravers have been able to use laser engraving technology to branch out into new and unique markets. Still more examples of new markets and applications include: patterns for quilting, scrapbooking, wooden signs, mirror marking, debossing dies, appliqués, packaging, cutout holiday decorations and stamp manufacturing. Some engravers are using lasers to cut and engrave logos onto soap, and one innovative reader is even using his laser to engrave chocolate peanut butter cups for use as wedding favors. Electronics, paper greeting cards, wood models and more can all be created and personalized with a laser engraving system. You get the idea.
     Wood—It used to be that a typical award plaque was made by burnishing or diamond engraving a metal plate and attaching it to a wooden plaque board. The look is attractive, but the process is somewhat time-consuming and costly, especially if there are any graphics involved.
     Thanks to lasers, engraving wood plaques now involves simply placing the plaque board in your laser and engraving to produce great looking wood products. The results are stunning. The “burned in” look of engraved messages, graphics and even photographs is very appealing for many applications and the entire process is extremely easy. Any type of wood, including wood veneers, can be engraved, making this an excellent choice for engraving a variety of products, such as boxes, desk accessories, pens and more. The other good news about lasering plaques is that even if your customer likes the look of a metal plate with a wood plaque, most ready-to-go plaques now come with a metal plate that is easily lasered.
     Acrylic—One of the most popular materials for awards and gifts is acrylic and, for the most part, laser engraving is considered the most popular engraving method because the process is simple, cost-effective, fast, efficient and versatile. Acrylic laser engraves easily, vaporizing instantly with the touch of the laser beam and leaving behind bright white letters. No special tools or techniques are required, and it is nearly an effortless process to engrave detailed logos and small text into acrylic. A laser can also be used to cut out (profile) shapes in acrylic with a beautiful, flame-polished edge finish.
     Photographs & Detailed Graphics—As mentioned earlier, laser engraving systems definitely have the upper hand when it comes to engraving any type of graphics, whether it’s clipart, a logo or a photograph. Photographs are essentially bitmaps or halftones, i.e. images made up of a series of dots, as are many logos and graphic designs. Because laser engraving is a raster process, these images turn out beautifully with little or no prep work. As noted, rotary engraving is a vector process, so bitmaps need to be converted to vector images in order to be engraved, a process that is possible but is much more complicated and time consuming.
     With laser engraving, adding graphics and photographs to items is nearly as easy as engraving text. It is possible, for example, to import a clipart image into CorelDRAW, place it in your layout and immediately engrave it—and with good results! You can import or scan a customer supplied photo or artwork for a logo and, with a few modifications, have a great-looking engraved product. In short, the detail and complexity involved in graphics and photographs is really not in the realm of rotary engraving’s capabilities and is better left to a laser system.
     Solid Surface Material & Stone—Solid surface material, a synthetic substrate resembling natural stone, and natural stone products such as marble and granite, are very popular in the R&I industry, particularly for high-end corporate awards, gifts, donor wall plates, etc. Adding text and graphics to solid surface material is very easy and really no different than personalizing other types of materials.

   
The FiberMark Laser Engraving System from Epilog Laser, Golden, CO, utilizes a fiber laser which can directly mark uncoated metals.   This lion cub image was laser engraved on black tile and then color filled with white paint.

     Laser engraving is a very popular option for personalizing solid surface material and natural stone. Solid surface material laser engraves easily (very much like acrylic), and on dark pieces of material, such as black marble, laser engraving produces a white, frosted look. Photographs laser exceptionally well on these materials. For example, you can achieve a black-and-white photograph effect by lasering a halftone onto a light cream or bone colored stone material and then color filling the image with black. Or, for a different effect, you can engrave a “negative” photo on black marble or Corian. It is also very easy to achieve intricate designs and text on marble and granite with a laser. While rotary engraving can be used to customize solid surface material, laser engraving has the edge because of its simplicity and speed.
Conclusion
     Of course, these aren’t all of the applications for these marking methods, but a sampling that highlights the best attributes of each. If you are new to the industry or are thinking of expanding your business, be sure to consider both laser and rotary engraving with respect to the products and services that you want to offer your customers.
     It could be that laser engraving is a perfect fit or perhaps rotary engraving better meets your needs. Or it could be that your business can benefit from both of these technologies. Laser engraving, for example, is an excellent method for quickly and easily engraving intricate graphics and photographs on materials such as acrylic, stone and coated metals and it is also an extremely versatile process. Rotary engraving, on the other hand, is the method to use for engraving existing products such as engravable gifts and for jobs involving mostly text.
     So when you are trying to weigh all of the pluses and minuses of the two personalization options, which method is the hands-down winner? If you are an experienced user who is familiar with both processes, your conclusion will likely be that both methods are best. The choice of which to use for any given job will depend on the specifics of the job.


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