Tag Archives: fail

123: Semi-Precious Stone Engraving

The smoky quartz gives away its engraving with visible lines in the star.

A recent client sent me a few small precious gemstones to see how easily they could be engraved. I did some tests on them, with varying results, and sent them back her way. We went with a really simple five point star to test the engraving quality—with the smallest one just .07″ in diameter!

The tiniest piece, topaz, didn’t seem to show the same engraving pattern as the quartz.

Out of this initial batch, the topaz and quartz both engraved beautifully, but the opal’s engraving was basically invisible. This is probably due to a combination of factors. Opal is completely opaque, so no light can come through the material to highlight engraving. It’s a consistent color throughout, and it doesn’t burn, which means the untouched surface is only different from the engraved surface in texture. It’s very hard to capture in pictures.

This image was processed to try to show off that the opal was engraved. The star is there, I promise! Look closely!

My client received her gemstones back, and made some observations: in one piece, the horizontal lines that make up the engraving (because of how raster engraving works) were visible even at the laser’s highest engraving density setting. She also felt that the engraving wasn’t very deep and was wondering if a deeper engraving would affect the overall quality of the engraving.

Conveniently, I found out that Jennifer had done some tests on gemstone beads before, so we had some quartz of our own, as well as some garnet, to do tests. I became determined to solve these problems and answer these questions without requiring a new shipment of gemstones.

I was pretty shocked to see that the individual lines of the engraving were visible; this is something that happens on lower density settings (like 4, which is used to reduce engraving time but can leave ultra-fine gaps between the lines in certain materials). At the max density, this normally isn’t visible at all. I decided to try to engrave my pieces slightly out of focus, increasing the laser point’s diameter so that each pass overlaps somewhat.

My later engraving tests on beads of quartz and garnet were… less than successful.

As it turns out, though, none of my testing worked quite the way I’d hoped it would. Maybe the gemstone beads’ facets were impeding the engraving, or both of my solutions weren’t solutions at all, but all I got out of six different attempts were excessive chipping and almost unrecognizable engravings.

They’re supposed to be hearts! While I engraved the first batch with stars, I figured hearts would be a good shape for the quartz and garnet beads. I don’t think the shape mattered much in the end.

I engraved three pieces of quartz. From left to right, I gave them one engraving pass, then two, then three, at the same settings I used for the client’s quartz seen above. This time the chipping was so severe that you almost can’t even see the difference between the three tests, but upon close examination the heart that was engraved three times was actually a deeper engraving—completely moot with how poorly it turned out.

For the garnet, I was testing whether engraving out of focus would result in a smoother engraving, and it certainly doesn’t seem to be the case. Perhaps the offsets (focused, 0.5″ out, and 1″ out) were too severe a difference to see any value, but even the focused heart on the left was nowhere near as clean an engraving as on the client’s gemstones.

So I think the moral of these disappointing results is to always perform subsequent tests on the same exact material. I wasn’t able to give my client a good answer to her questions with these tests. Still, I’m fairly convinced now that chipping will prevent multiple passes from getting a deeper engraving without reducing the engraving quality, but the jury’s still out on whether adjusting the focus can have a positive effect. We’ll find out eventually!

89: More Laserable Magnet

I’ve talked about this particular kind of laserable magnet before, but for this week’s project, I took the same magnet material and determined whether I could use it as a replacement for the strip of magnet material I normally use for my set of dialog boxes.

The current strip solution (top) and the proposed replacement.
The current strip solution (top) and the proposed replacement.

I currently use a 1/2″ strip magnet stored in rolls for this type of product, and while it does the job well, I appreciated the reduced overall thickness and cleaner lines I discovered during the shaped magnets project.  But there were three other things to consider before I could revamp the Earthbound and Final Fantasy dialog boxes with the new magnet type: efficacy, material cost, and processing time.

The reduced thickness of the new magnet material (bottom) looked great.
The reduced thickness of the new magnet material (bottom) looked great.

Since we’re talking about magnets, it’s important to make sure they can hold themselves (and hopefully several other things) securely against the surface you’ve stuck them to. One example of a magnet that doesn’t hold up is the inkjet magnet material I used for some full color Megaman Robot Master icons I made a while back. While they looked great, just one of those magnets couldn’t hold a single thing beyond itself—the magnet simply wasn’t powerful enough. (Thankfully, those magnets were at least strong enough to hold themselves up.) In this case, the laser cut magnet material, when cut to the full size of the Earthbound dialog box, was able to match the two inches of strip magnet I use in holding power, so I was glad not to have to worry about that.

While the laserable magnet ended up costing more per magnet than the strip magnets I use, I wasn’t interested in adjusting prices to accommodate this change. Because of this, the convenience of laser cutting perfectly shaped magnets would have to outweigh that additional cost.

Unfortunately, while it was certainly more convenient to tell the laser to cut hundreds of magnets rather than doing it by hand with a precision blade, the introduced clean-up step was so time consuming and unpleasant that there was no way this was going to be a viable upgrade without significantly increasing the price of the product, which wasn’t on the table.

This magnet soot, appropriately, stuck to everything.
This magnet soot, appropriately, stuck to everything.

The problem lies in the way this magnet material dissolves when cut away with the laser. It leaves a fine gritty dust of magnet material that was easy enough to clean off of the black acrylic used in the aforementioned shaped magnet project. With the white base acrylic used in both the Earthbound and Final Fantasy dialog boxes, though, this grainy magnet soot was almost impossible to clean away without damaging the surface of the dialog box. Even with isopropyl (and perhaps in part because of isopropyl) I was unable to clean the finished pieces without either staining the white exposed acrylic or seriously scuffing the black cap layer.

My first cut tests were done with the magnet already affixed to the acrylic, but I even considered cutting the magnets separately and then affixing them to the acrylic pieces after both were clean. This added yet another step to the process and, sadly, didn’t mitigate the unreal amount of time spent trying to wash away all of the grime produced when processing the material.

This laserable adhesive magnet sheet really neat product, and it allows me to create some really neat special magnetic pieces, but the time and care that goes into making sure the clean-up process doesn’t damage the final piece means that I just can’t consider them for the standard line of dialog box magnets at Pixelaser. I’ll be keeping an eye out for more laserable magnet options in the future (and if you know of any, please do share!) but for now, our stalwart magnet strips will continue to do the heavy lifting. Sweet fresh feel!

 

19: Fire Flower Vase

My first attempt at etching glass was a hint of things to come.
My first attempt at etching glass was a hint of things to come.

“Well, that didn’t work,” ended my first foray into laser etching glass. I tried to create a design similar to the mesmerizing microscopic pattern found on the back of the Nexus 4 smartphone, this time on the glass back of a spare iPhone 4 that my nephew graciously donated for the cause. The resulting pattern was too big and the laser settings weren’t appropriate, making each vector line look more like a coincidentally straight shatter line rather than the light-reflecting divot I’d intended. I’ve shied away from etching glass since, and after this week’s project, I’ve realized I’ve still got a lot to learn!

Make sure to level the surface you want to etch!
Make sure to level the surface you want to etch!

While I’m doing general graphic design at Eagle Engraving in St. Charles, IL, my coworker and fellow laser ninja Monica is often etching all sorts of designs into glass. I’ve been envious lately of her knack for making designs spring forth from glass, and while I don’t yet have the rotary attachment necessary to etch round objects—like pilsner glasses—I did have a square vase conveniently made of mostly flat glass. Because the sides of the vase were tapered, I had to prop up the bottom side so that the surface was parallel to the laser plane. I ended up using a box of dialog boxes and a handy level to double-check my work.

The two designs chosen for etching were, perhaps, too many shades of gray.
The two designs chosen for etching are another sign of my Nintendo upbringing.
The lightest halftone didn't etch consistently. It almost looks like frost.
The lightest halftone didn’t etch consistently. It almost looks like frost.

The first etch was cut with the default raster etch density (5) and the grayscaled art above. I went with full power and full speed just to see how it would turn out, and the lightest halftone didn’t play well with mostly flat glass, only mostly etching. Apart from that, this turned out to be the single best contrast out of the set of four etches I made. The second etch, at maximum density, was overkill; the raster lines were so close together that wiping down the surface flaked away a lot of the glass, as shown below.

Etch glass at too high a density and much of it will chip and flake away.
Etch glass at too high an Image Density and much of it will chip and flake away.

 

The lower image density didn't help prevent chipping. Maybe the halftone was too dark.
The lower image density didn’t help prevent chipping. Maybe the halftone was too dark.

My third fire flower was etched at a lower image density. While this prevented chipping, some tinkering with the halftone patterns resulted in even more chipping in a much more widespread way. While the contrast was improved from etch two and nearly as good as etch one, the damaged areas really stand out. Who can guess where many of these tiny glass slivers are?

I had to cut at least one Super Mario World flower.  I settled on the default image density again after the tweaked results were poor, and while he’s still hard to see thanks to haphazardly adjusted gray levels, you can still see how much more personality he has. That just won’t do—he’ll only last another game or two, anyway.

Look at that smug bastard.
Look at that smug bastard.

I might have to table glass etching again for a while; I was unable to achieve satisfactory results on this particular piece. Still, I’ve since had a chat with laser ninja Monica, about her own tricks for getting better results on glass, so you can be sure you’ll be reading more about it here in the future!