In an experiment to determine whether MABAS name tags could be made more easily with a laser than with a rotary engraver, I took some strips of Velcro and some spare laserable plastic from work (Thanks, Eagle!) back to my house, slapped ’em together, and set my laser to them. The result could determine the process for making name tags at Eagle in the future, but more importantly it gave me an excuse to play around with some Velcro.
I wrote before about layering before lasering, and there I learned that it was a viable way to save on building items after they’re made with the laser. In this case, I pre-applied the Velcro because the alternative meant precisely aligning hundreds of 2″×3/8″ bits of plastic to hundreds of 2″×3/8″ snippets of Velcro, which certainly doesn’t sound fun.
Cutting a handful of name tags from a single 2″ strip of the combined plastic and Velcro was indeed significantly faster than the rotary engraving process, which engraves a single tag at a time and doesn’t shape the tags. Even more significant time savings can be had by cutting as many name tags as the laser can hold—in the range of 250—and it allows the operator to “set it and forget it,” not needing any input during the process.
Unfortunately, the laser burn does leave soot on the white surface, which needs to be wiped off with alcohol and introduces a new per-tag step that needs to be accounted for. It’ll be up to Eagle whether they choose to incorporate the new process, but I’m thrilled by the prospect of using precisely shaped Velcro backing as an attachment option for my own future projects.
There’s something classy about a plaque with a neatly rotary-engraved plate. Because rotary engraving traces the outline of each letter or shape and fills are created by repeating inset paths, you get an illusion of depth that can look stunning with the right design and lighting.
Lasers typically engrave in a fashion similar to how inkjet printers print: it scans back and forth across the surface, engraving the design one horizontal line at a time. That’s called raster engraving, but lasers can also perform vector engraving: it’s the same process as vector cutting, except your goal is to lightly carve the surface rather than cut straight through your material. Because of this flexibility, though, I realized that I might be able to recreate the beautiful depth effects you can create with rotary engraving.
I prepared a file in Illustrator, featuring a quote that Shelby wanted me to “engrave onto something sometime,” and used repeated Offset Path commands to recreate the way rotary engravers perform fills.
There were a few mistakes. I used too much power on the first engraving, which made for a line so thick that it obliterated any impression of the inset vector paths and faux-bolded the typeface. I engraved that first pass on my best plate, which left the revisions on plates without decorative borders. Then, I lowered the power on the second engraving, revealing that my paths were too loosely inset, resulting in awkward gaps in the letter forms. I engraved too lightly on the third pass, leaving the surface layer only partially engraved away and causing a faint green color cast on the engraved brass. My final mistake was engraving anything on that hideous purple marble print plate. Seriously, how could anyone read anything engraved on that?
Throughout the experimentation, though, I was never successful. That’s because rotary engraving actually carves little channels into the surface of the metal, which catches light differently and creates the illusion of depth. No matter how much power I shoot at it, my 40w laser isn’t going to leave a dent on metal, and no matter how little power I shoot at it, the surface material isn’t thick enough to provided a substitute channel.
I’ve laser-engraved an axe handle before, as a test to determine whether I could process some of the longer pieces for Eagle Engraving. It was successful, and the first actual order came in for a laser engraved large axe handle. Since one step of the process wasn’t covered in the previous project, I’ll be going over it this week.
LaserDark is a spray paint meant to darken the engraved portions of wood that might otherwise not have enough contrast. Plain brown spray paint might work in some cases, but LaserDark dries more quickly to prevent the color from bleeding into the wood grain in the unengraved portions.
The engraving went well, using the same process and settings as described in the previous entry on axe handles. Just make sure that you use masking paper so that you can spray only the engraved area and tear away the paper after the spray dries. One thing I immediately realized is how dark these engravings turn out. Because I’m using a very low 25% speed to get a deep engraving, there’s a lot of burn causing a great deal of contrast even before we begin spraying. This doesn’t invalidate the spray’s usefulness in other situations, though, like lightly engraving oak or maple.
As instructed, I sprayed the colored coat first and gave it several minutes to dry. Afterward, the clear coat was applied in the same fashion and I gave it a half-hour to set. LaserDark dries quickly, so they only recommend waiting 15 minutes. It’s also suggested that you remove your masking paper within an hour so that it’s easier to remove.
Unfortunately, it seems like a little color did bleed beyond the area I’d engraved. It’s disappointing, considering I took extra care when applying the masking paper to make sure it was firmly and evenly applied.
According to the comments section on LaserDark’s website, a testimonial from one customer reads “It’s fast, simple, quick-drying and does not bleed or seep like regular wood stains.” This sole testimonial, though, was left by the owner of an awards company that operates at the same address as the company that produces LaserDark, so I’m not entirely sure it’s actually a testimonial and not just marketing.
Regardless, it’s possible I applied too much color spray; a “medium coat” is suggested. Also, a little bit of sanding did the job nicely, and this handle is going to be further buffed and polished at Eagle and will almost certainly turn out looking awesome.
One of the products that we make at the engraving company I work for is a commemorative axe for firefighters. It’s an impressive finished piece that includes the firefighter’s department patch engraved on a super-shiny axe head and it’s typically mounted on a giant plaque that features other items and elements from his or her career. An optional feature includes laser engraving the firefighter’s surname on the axe handle, and those handles can range from a foot to well over two feet long!
Since the laser bed available at Eagle Engraving isn’t quite long enough to process the larger axe handles we offer, I was asked if I could fit the handle in my larger platform, so I had to give it a shot!
As it turns out, the handle was quite a bit longer than the 24″ operating width of the laser bed. It was even a bit longer than could fit inside the enclosure at a 90 degree angle. But I had some success when I angled the length just right. I was worried that I would have to operate the laser with the front door’s security defeated—an option that is useful for engraving one end of incredibly large objects like oars—but it turned out that I’d be able to close the laser and let it operate normally as long as I figured out the angle the handle was sitting at so that I could match it with the design.
The only caveat I ran into when loading a piece that was longer than the laser bed was making sure I didn’t damage the z-axis screws. With the axe in its position, moving the table up on the z-axis to focus the laser on the handle surface meant the axe was coming dangerously close to the top lip of the enclosure. Raising the platform much more would surely cause the handle to catch between the platform and the enclosure lip. That would cause the z-axis to fall out of calibration and could possibly damage the machine, so I was very careful about the space I had when positioning the handle. Always be aware of the enclosure limits if you’re going to be engraving something bigger than your bed. You do not want to damage your table’s motion systems.
I drew a few simple vector lines in Illustrator at various angles and ran them with the laser door open so that I could see how the red dot laser traced the axe handle. It only took a few tries to settle on -17 degrees: the exact rotation that I’d need to make an engraved surname fit straight on the slightly cockeyed length of wood.
The surname I chose was “Schoeberlein,” after Adam Schoeberlein, the first paid fire fighter in Aurora, IL and the chief in 1875. I laid his name out in Clarendon Black, which I’ve had a small obsession with since discovering it while designing flyers for Eagle.
That -17 degrees was put to the test when I very lightly engraved it into the transfer tape I wrapped around the handle. Once I was sure the name would look even on the handle, I committed to the angle and engraved again with full power and quarter speed. The slow speed meant a nice, deep engraving, matching the sample I borrowed from Eagle with Colonel Williams engraved on the side in I believe Times.
The depth turned out great, and the angle was spot on, but there’s still a lingering issue. At work, Monica uses LaserDark to darken the engraved portion for increase contrast. I don’t have that product on hand, so while the thick slab serifs of an all-caps Clarendon really make the name stand out, Shoeberlein’s friend Colonel Williams stands out a little stronger with nearly black letters. Presumably, applying a coat of LaserDark to Schoeberlein would be the best of both worlds.
The question that started it all was “Can you fit this axe handle in your laser and engrave it?” Thanks to this week’s project, I know the answer. It’s the best answer. “42.”