|Photos courtesy of Roland DGA Corporation, Irvine, CA.
There was a time, not that many years ago, when quite a few EJ readers were exploring the magic and wonders of laser engraving. “Wow! Can you really engrave something using a beam of concentrated laser light?” “Where’s the cutter?” another reader inquired.
For a long time, most of the engraving professionals who purchased their first laser did so with an extensive array of knowledge and experience under their belt doing “mechanical,” also known as “rotary,” engraving. Times have really changed. Nowadays, most new people entering the industry start out with a laser and skip the step of becoming an expert in the field now called rotary engraving.
There are also other people now entering the industry who don’t know much about either engraving technology. The following letters typify these individuals.
One reader writes:
Hello. I am writing to you with a huge favor to ask. I am looking to get into engraving. Currently, I am attempting to compare what would be the better option: a laser engraver or a rotary (mechanical) engraver? For a startup business, which would you personally recommend?
Another reader e-mails:
I am seriously considering buying an engraving machine for my jewelry store. The problem is that I am finding it very difficult to determine what I need. I can’t seem to find equipment that does everything I need it to and I can’t afford to buy two or three machines. I want to engrave all types of jewelry, including photos on jewelry and the inside/outside of rings. Engraving on acrylic and glass is also a possibility. Any information would be greatly appreciated.
For these readers, and others who are considering either opening an engraving business or branching out into a new field, the best advice is to acquaint yourself with the engraving technologies available, which are primarily rotary and laser engraving, and then make an educated decision from there. This article serves as a basic primer about rotary engraving—what it is, how it works and all of the wonderful opportunities it can present to an engraving business. Look for a follow-up article about the basics of laser engraving in a future issue.
For someone new to the engraving business, or someone only familiar with laser engraving, terms such as diamond drag engraving, burnishing adaptors, rotary cutters, micrometer dials, speeds and feeds, and cutting angles probably don’t mean much. In fact, they might as well be written in a foreign language. But in reality, they represent the very core of our industry—rotary engraving.
Actually, the term “rotary engraving” is a misnomer. It has historically been called “mechanical engraving” because the cut is made mechanically using a cutting tool. However, with the advent of laser engraving a lot of users have adopted the term “rotary engraving” to describe what we do with a rotating cutter or non-rotating diamond graver.
||Using a tapered rotating cutter to cut (profile) badges out of plastic results in an attractive, beveled edge. Photo courtesy of B.F. Plastics, Inc., North Lawrence, OH.
Long before lasers came on the scene, mechanical engraving machines were making their mark on mainstream industry products such as trophies, plaques, signage, giftware and jewelry, in addition to items off the beaten path like bowling balls, skis and computer key caps.
It’s true that lasers have many advantages—they’re versatile, easy to use and affordable. But it’s also true that rotary engraving is still alive and well in our industry. Many industry veterans use rotary engraving equipment in their businesses for certain types of work, whether it’s engraving batches of trophy plates or personalizing watches and other fine jewelry. The truth of the matter is, rotary engraving is the preferred method—and sometimes the only practical method—for certain types of jobs.
For rotary engraving novices, the idea of plunging into rotary engraving can be daunting. The reality is that rotary engraving is really not that difficult and it doesn’t necessarily require a great deal of skill, especially with the new machines and equipment available today. Here’s a look at the basics of rotary engraving.
What is Rotary Engraving?
Rotary engraving is the process of using a spinning cutter in a motor-powered spindle to cut or “rout” into material, either completely through the substrate to create cut out shapes or holes, or at a predetermined depth to create engraved grooves that form characters and graphics. Diamond engraving, aka “diamond drag” engraving, is a variation of rotary engraving in that you can use the same machine but you use a diamond-tipped, non-rotating cutter called a “graver” to make a mark on various materials by scribing lines or grooves into the surface. This method is primarily used for engraving metal.
Rotary Engraving Applications
One of rotary engraving’s best traits is that it can be used to engrave a wide range of materials, including a variety of plastics, acrylic, glass, ceramic, wood, stone and solid surface material. Unlike CO2 laser engraving systems, rotary engraving systems utilizing a diamond drag engraver can also engrave on just about any type of machinable bare metal, including aluminum, brass, stainless steel (machinable grades), silver, gold, titanium and platinum. This means you can use rotary engraving to personalize just about any metal item, including off-the-shelf items you can buy anywhere. Just a partial list of products you can rotary engrave includes Rolex watches, identification bracelets, metal pens, die struck medals, charms, 14K wedding rings, bridal cake knives, brass or aluminum plates, etc. If it’s uncoated metal, you can engrave it. If it’s coated, you can engrave it. Diamond drag engraving will work on precious metals, semi-precious metals, stainless steel, brass, pewter—you name it!
Because of the wide range of substrates that rotary machines can engrave, you have the opportunity to take your engraving skills into a variety of different markets. The awards market, of course, is a big area for rotary engravers and includes products such as trophy plates, plaque plates, corporate gifts and acrylic awards. And while lasers are also great for engraving most award products, they are not necessarily suited for many traditional engravable gift items, such as jewelry and metal products like tankards, flasks, compacts, boxes, luggage tags, etc.
Signage is another area where lasers and rotary engravers both have a foothold. However, when it comes to ADA signage, rotary engraving holds the advantage because it’s easier to create the required raised lettering and Braille dots. You can use a rotary machine to create the letter cutouts and then switch the cutter, drill Braille holes and place the Raster Braille beads directly into the holes, which is something you really can’t do with a laser.
Another major market area for rotary engraving is the industrial sector. Rotary engraving is excellent for machine tags, legend plates and permanent marking on fixtures and equipment.
Laser and rotary engraving also produce different “looks,” and in many cases it’s the look of rotary engraving that customers want. Rotary machines engrave into the material, rather than mark or burn it, producing noticeable depth that you can feel, a characteristic that is often desirable for appearance and permanence.
One of the characteristics of engraving that really sells is its “look.” Diamond engraving, in particular, evolved out of the artistry of hand engraving. Many rotary engraving fonts are ornate and stylized, being reminiscent of a hand engraver’s “lining cut” made in precious metals. Many manufacturers offer special type fonts for initialing and monogramming as well as decorative fonts such as script and Old English.
Options in Rotary Engraving Equipment
Until the late 1970s, manual engraving machines—also known as pantographs—were the only type of engraving equipment on the market. With a pantograph machine, you manually lower the cutter to the material and create engraved characters by holding down the cutter and tracing a master template with a tracing stylus. This “workhorse” machine was used for engraving everything—trophy plates, plaques, pens, watches, computer key caps, wooden signs, baby cups, 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, computerized engraving machines use computer type fonts and digitized logos for the “artwork” and sophisticated electronic controls and stepper motors to mechanically lower the cutter and move it along the X and Y axes to engrave. Although some shops might still have a pantograph in the back room, computerized engraving has taken over as it has drastically reduced the time and labor involved in rotary engraving.
There are a wide variety of computerized engraving machines available to suit almost any application. They include small countertop systems that take up less than one square foot, systems capable of engraving rings, gifts and cylindrical objects, and large flat table systems that can engrave a large quantity of badges or signs at one time. All of the major machine manufacturers, including Gravograph, Newing-Hall, Roland DGA, Vision Engraving Systems and Xenetech Global, offer a complete line of computerized engraving machines in a variety of sizes and configurations. The main differences between these systems are cost, size and capabilities.
Generally speaking, a smaller rotary machine has an engraving area of around 6" x 8" to 9" x 12" and ranges in cost from $4,000-$8,000. These machines are designed for engraving items such as jewelry, award plates, small gifts, pens, single badges and small industrial plates and tags. Several manufacturers have also introduced “all-in-one” systems that include a computer, software and a small engraving table in a compact machine that can fit on a countertop. These machines are designed for engraving items like tags and jewelry “on the spot” with very little setup and just the touch of a few buttons.
You can also purchase a “specialty” machine if you plan to engrave items beyond the “flat” products like plaque plates, name badges and signs. For example, some systems feature a built-in cylindrical engraving fixture for engraving round items like mugs and Revere bowls, a ring/bracelet engraving attachment and/or a liquid coolant system which is needed to engrave glass. Prices vary depending on the system’s capabilities and the manufacturer, but a general price range is $14,000-$16,000.
Mid-sized engraving systems have larger engraving areas, e.g. in the range of 12" x 12" to 16" x 12", and have a price tag of around $10,000-$20,000. Mid-sized machines can do everything a smaller system can, plus larger gift items, signs and industrial parts.
Large rotary engraving systems typically feature a movable “bridge” that travels across the table allowing you to engrave very large items or multiple items at one time, such as a large sign or panel, or a batch of badges, signs or nameplates. These machines can have a working range of 24" x 48" or larger, depending on the manufacturer, with prices ranging from $12,000-$30,000.
Rotary Engraving Software
A major link to successful computerized engraving lies in the software. A good software package allows you to quickly and easily create text, graphics and even photographs that can be engraved on your computerized system. Most engraving machine manufacturers offer their own proprietary software, either as an option or bundled with their engraving machines, and some third-party software developers, such as CADlink Technology Corporation, Ottawa, ON, Canada, offer engraving-specific programs. These packages are custom built to drive engraving machines, which makes communication between the software and the table exceptionally smooth.
Most of the major machine manufacturers offer engraving-specific programs to make your job easier. These software packages are typically sold in different versions, ranging from basic to more advanced, so you can select a program based on your applications.
If you are a laser owner, chances are you’re using a general-purpose “drawing” program, such as CorelDRAW, as your host software to do your layouts. Many of the rotary systems allow you to use CorelDRAW for your layouts, but most users find that Corel and other general-purpose programs don’t work very well for rotary engraving. The reason is that rotary engraving is almost exclusively a “vector”-based process (like vector cutting with your laser). Rotary fonts are also vector-based fonts. As a general rule, it’s both easier and faster to do most rotary engraving jobs using rotary engraving software.
One of the major advantages of engraving software is that it gives you access to a wide variety of engraving-specific applications. For example, many engravers regularly use a feature known as auto layout for standard jobs. Auto layout lets you automatically create attractive award, gift and sign layouts based on basic information that you input, such as type size and line spacing. Another popular engraving feature is “matrix” engraving, also known as multiple plate engraving, which is the software’s ability to consecutively engrave a series of small plates onto one larger piece of material in a step-and-repeat fashion. A similar feature, called batch engraving, involves consecutively engraving the same layout but different text on a series of precut plates. Both of these are time-saving features for jobs like badges, signs and nameplates.
|The Express Desktop Engraver from Vision Engraving & Routing Systems, Phoenix, AZ, is an entry level engraving system with a small footprint.
||The IS900 from Gravograph, Duluth, GA, was designed for engraving medium to large sized jobs.
As noted earlier, today’s machines are not nearly as complicated as they were many years ago, and much of the credit for that goes to improved software. For example, some software now allows you to essentially define and position the layout directly on the item to be engraved using a red laser pointer. Say, for example, you need to engrave a belt buckle that has a small rectangular area in the lower right corner designated for engraving. You can manually jog your engraving machine’s spindle to each of the four corners of the rectangle and register those points in the software to define the engravable area. The software will then display the rectangle (engravable area) on your computer screen where you can input text/graphics. When the job is sent, the engraving machine knows exactly where on the buckle to start engraving. This feature is extremely handy for engraving jewelry and other small engravables that aren’t necessarily symmetrical. It is also a great option for engravers who prefer a visual approach to engraving as opposed to a mathematical one.
Another trend in recent years is the ability to generate and engrave just about any kind of graphic image, including logos and photographs. This can be accomplished in a variety of ways, including scanning and importing graphics from other programs such as CorelDRAW, and then converting them into a format suitable for engraving. Most of today’s software also provides a variety of design capabilities for creating your own graphic images.
Most engraving-specific software also has a variety of layout and engraving features for specific applications, such as creating ADA signage, including Braille and raised lettering, engraving seals and generating dials for industrial control panels.
Rotary Engraving Fonts
Another advantage of computerized engraving software is that most programs include a variety of fonts that are true “engraving fonts.” Many graphical fonts, such as those found in CorelDRAW and other “Windows” applications, are bitmap fonts or, in other words, they are made up of dots or they are basically outline fonts. This is fine for laser engraving or printing on an inkjet printer, but these fonts are not readily engravable because rotary engraving is a vector-only process. Engraving fonts, also called “stick” or “stroke” fonts, are made up of vectors (lines and arcs) that can be engraved using multiple strokes with an engraving cutter.
Many programs are also compatible with TrueType fonts (of which there are thousands available), which may or may not be included with the software. Depending on the font and the look desired, TrueType fonts might need to be converted into stroke fonts for engraving, another feature of many programs.
Rotary Engraving Basics
With the proper equipment and software, all you need are some basic accessories to get started. Engraving cutters are the tools used to get the job done. Cutters are made from different materials and in different configurations. Choosing a cutter for a job depends on the material, application and overall look you want to achieve.
||Some systems feature a liquid coolant system which is needed to rotary engrave glass. Photo courtesy of Xenetech Global, Inc., Baton Rouge, LA.
Spindles—The spindle is the device that holds the cutter in place during engraving. Most of the engraving machines used in this industry come standard with a “top-loading” spindle, meaning that a cutter is inserted into the top of the spindle and (usually) is secured with a threaded “cutter knob.” Cutters for top-loading spindles are available in various shank sizes, including 1/8", 11/64", 1/4", 4mm and 6mm diameters as well as various lengths to fit the spindle. The advantage of a top-loading spindle is that you can quickly and easily load and unload cutters, and preset the cutters to the desired engraving depth at the onset of the job.
Collet spindles are also available, particularly on larger, industrial type machines. This type of spindle features a collet (similar to a drill chuck) that tightens around either a bottom- or top-loading cutter to hold it in place. This type of spindle is more rigid and precise, but involves more time to change cutters.
Machinist-type high frequency spindles that run at 50,000-60,000 rpm are now also 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 in stainless steel, milling dies for hot stamping and industrial cutting and detailed milling applications.
Diamond Gravers—A diamond graver consists of a small, conical shaped diamond set into the tip of a metal cutter shank. These non-rotating cutters can be inserted into a rotary or diamond spindle (and used with the spindle motor turned off) or used with a spindle designed specifically for non-rotating diamond engraving. You can also use a diamond drag adaptor, which is essentially a small diamond cutter that attaches to the bottom of a rotary spindle.
A diamond cutter (graver) “drags” across the material surface (hence the name diamond drag engraving) to create a shallow, fine-line cut with a bright, polished finish. This type of cutter is used to engrave into metal, such as brass, aluminum and pewter gift items, trophy and plaque plates, jewelry, etc. Diamond gravers are available with various tip angles. A 120-130 degree angle is used for general purpose engraving, a 90 degree angle cuts deeper and is well-suited for hard metals or epoxy coatings (on coated pens, for example) and a broader angle, e.g. 140 degrees, makes a shallow, wide cut that works well on soft metals like pewter or gold.
|Cuts made with a rotating diamond burnishing cutter are wide, shallow and brilliant.
||Many rotary engraving fonts are ornate, such as this diamond engraved interlocking script monogram.
Rotating Cutters—Rotating cutters can be manufactured from “high speed steel” or tungsten carbide. Often referred to simply as “carbide cutters,” today’s tungsten carbide cutters are usually made from high performance “micrograin” carbides. These are generally more popular for engraving applications because of their toughness and durability. The cutters used for the widest range of engraving applications have a conical shape with a half-round configuration, which means that the cutter is split in half and ground with a single, angled cutting edge. Quarter-round cutters are also available for special applications, such as engraving hard metals.
Conical (tapered) cutters are ground with a fine, sharp tip; the size of the tip determines the width of the cut. Cutters are also available with different clearance angles, depending on the material being engraved. For instance, soft materials, such as plastic, typically require larger clearance angles in order to allow the material chips to escape during engraving. You can also purchase or grind cutters with different cutting angles for different applications. For example, the standard cutting angle is 30 degrees, but you might choose a cutter with a 90 degree included angle to create a deep V-groove for a dramatic effect in a material like acrylic.
When used to engrave into materials like plastic, metal, wood, solid surface material, acrylic, etc., a conical cutter produces a V-shaped cut with a flat bottom. When used to cut out shapes, e.g. cutting name badges out of plastic engraving stock, these cutters leave an attractive, smooth beveled edge.
The other common type of rotary cutter is a parallel cutter. Instead of a conical shape, a parallel cutter has a straight cutting edge that is parallel to the cutter’s axis of rotation. When used to engrave, this type of cutter produces cuts with straight walls and a flat bottom. When used to cut completely through the material, the result is straight side edges, as opposed to angled edges, an effect that is particularly desired for applications such as control panel engraving where the panel needs to fit over dials, knobs and keys.
|An advantage of rotary engraving is that it can be used to engrave all types of machinable metals, including stainless steel.
||Making ADA signage, including raised lettering and Braille, is a straightforward process using a rotary engraving machine. Photo courtesy of Vision Engraving & Routing Systems.
Burnishing Cutters—A burnishingcutter is a rotating cutter with a multi-faceted tip. These cutters are used in conjunction with a burnishing adaptor, a spring-loaded mechanism that fits on top of the cutter and allows it to “float” across the material surface. “Burnishing” essentially involves skimming away the top lacquered surface of the material and just a tiny amount of the base metal.
Burnishing tools are wider than a diamond graver and are available in a variety of tip sizes, just like traditional rotary engraving cutters. One of the advantages of burnishing is it’s very fast, and you can use very simple single-stroke fonts while still achieving a bold, wide cut by using a wide-tipped cutter. Burnishing is especially popular for use on lacquered brass plates where the wide-cut characters can be blackened for contrast through the use of an oxidizing solution.
Specialty Cutters—There is also a wide variety of specialty cutters available designed for certain applications. For instance, spiral flute cutters (“end mills”) have spiral shaped cutting edges, similar to a drill bit. These are used for drilling and engraving or milling hard materials, such as stainless steel. There are also special cutters available for certain jobs, such as engraving ADA Braille signage, eyeglasses, bowling balls, stencils and plastic pens.
Chips & Removal—A principle virtue of rotary engraving is its ability to produce a really deep cut, if desired, which will create a hole or slot that goes all the way through the material. In most cases, a rotating cutter will produce chips as it cuts the material. A vacuum “foot” or adaptor is an option for removing material chips when you cut. A vacuum adaptor consists of a nose cone that is attached to a Shop-Vac or other vacuum chip removal system that removes material chips during engraving. This is useful for keeping the work area clean, e.g. when engraving plastic or making deep cuts. In some cases, depth noses are not used, mainly if there is a risk of scratching the material surface, e.g. deep engraving on metal.
Holding Jigs—As mentioned, the rotary engraving process is based upon feeding or pushing a cutting tool through the material to make a cut via material removal. This process is unlike laser engraving where only a beam of light touches the material. As such, the item being rotary engraved needs to be clamped or secured in the engraving machine to prevent it from moving during engraving. This is accomplished using various clamps and fixtures, often referred to as holding jigs, which are available from machine manufacturers and distributors.
|Attachments are available for some rotary engraving systems that allow you to engrave on the inside and outside of rings. Photo courtesy of Xenetech Global, Inc.
||Shown here is the Newing-Hall model 350 engraving a pewter mug.
There are a variety of holding jigs available depending on the type of machine you have and the type of work you’re clamping. For example, you can hold flat items and material sheets using clamps, sticky mats (typically a rubber mat with a reusable sticky surface) or double-faced adhesive tape. There are also jigs designed to hold specific items, including flat plates, pens, medals, medallions, watches, bracelets, rings, award plaques, door knockers, silver trays, tire gauges, ID bracelets and more.
Most manufacturers also offer “universal” jigs that will hold a variety of odd-shaped items by inserting pins into a series of holes in the jigs to secure the item. There are also small vises available that can be clamped to a flat table to hold small jewelry and gift items. If you have a basic selection of about 8-10 sets of holding jigs, you can probably hold 98 percent of the engravable items that go through most industry-based shops.
Is Rotary Engraving for You?
This “bird’s eye” view of rotary engraving should give you a good idea of what one of the industry’s most versatile marking methods is all about. Rotary engraving can open up avenues to a wide variety of markets that other technologies cannot, including jewelry, giftware, glassware, ADA signage and much more. The equipment available today is state-of-the-art and there is a wide variety to choose from, whether you’re looking for a small gift engraving system for products like picture frames, vases and jewelry or a larger setup for jobs like architectural signage and volume production. The process itself is equally straightforward and continues to represent a major area of our industry. Perhaps it’s time to take a closer look at rotary engraving and what it can do for your business.