121: Anodized Aluminum Moai

When Jen and I were first researching buying a laser, we didn’t plan on buying the one we ended up with. We were looking to get a small, semi-portable solution. But my brother Johnny found a family out in Terre Haute, Indiana, who had owned their laser for about a year and realized they weren’t really using it as much as they’d like and they wanted to sell it. Buying the used laser meant I inherited some of the previous owner’s mistakes—like a damaged lens and rulers that had art engraved on them—but I had plenty of time to cover up those mistakes with my own.

One of the benefits of buying used is that the previous owner didn’t need their material stock anymore either. Bundled with the machine were dozens of small samples of various laser-ready materials, including a piece or two of black anodized aluminum. I dug up one of those old pieces while cleaning out the office, and realized that I hadn’t spent much time engraving on the medium, so I decided to give it a try!

I’ll probably never find out who these two are, but I’m sure they had fun engraving this picture!

This piece of anodized aluminum had a remnant from the previous owner: an engraving test of their own that they didn’t keep. It also had one corner clipped off, so maybe the leftover engraving I have was a test run and they kept a more successful engraving. Either way, the laser is way too low-power to actually cut through this metal, so I’d be limited to engraving the surface. I don’t have the tools necessary to cut this into a better shape, so our two buddies will, for the time being, remain a part of this experiment.

Full color, desaturated, and then inverted so that it would engrave properly.

I settled on a picture of the large moai head Jennifer took some years ago. This picture converted into black and white really well, and as you have to with all materials that engrave from dark to lighter colors, I had to invert the picture so that the laser would fire on white, not on black.

My first engraving test was too powerful: I typically use 35% power to lightly engrave surfaces, but the laser overpowered the black, creating a blown out image. I settled on 20% power—recommended in the laser driver’s settings for this medium—and the contrast was much better. That’s what I get for ignoring Universal’s built in material settings!

Because it only took one pass to get an acceptable result, I decided to use this project to compare a few of the settings available in the driver. When engraving art that has shades of grey, the machine has to dither to convert those to art it can engrave. The machinist can choose to have the laser convert those shades to a patterned halftone, use an error diffusion method, or use a threshold to convert the art to black and white. You can also select from seven different Image Density steps; the lowest step is the quickest and skips the most space on the material between horizontal lines, and the highest takes much longer and leaves very little space between each pass. The difference between those settings is pretty remarkable, but I didn’t want to do seven passes for each, so I decided upon odd numbered settings.

In the end, I made a matrix of engraving settings: each row is a different Dithering option, and each column is a different Image Density. Twelve engraving passes later, here is the result.

The full grid of engravings. Most of the difference in detail is lost in these photographs.

As expected, the image density settings took different amounts of time to finish. Density 1 took only 47 seconds to complete. Density 3 took 2:08, while the default density setting of 5 took 4:10. The maximum density setting took a whopping 15:13. Since the engraving speed isn’t really affected by the dithering option, the results were almost identical down the columns.

Lower density engravings make the dither pattern more obvious.

It’s clear in person (and less so in this photography) that error diffusion is the best option to get a good clean photograph engraved onto this medium. I’d be willing to bet that will be true for most materials, as the halftone pattern (while great for low color artwork) just doesn’t blend a photograph’s natural shades well. This is even true in the lower image density settings.

While the dither pattern all but disappears at image density 7, the time spent is too costly.

I think the default image density setting, 5, was well chosen. It’s an excellent middle ground between the time spent and the resulting image. You can’t really get a sense that the image is comprised of multiple horizontal lines like you can in setting 3, but you’re also not spending 15 minutes on a 2″ by 2.25″ photo.

120: Fluorescent Samurai FightStick

Somehow for all the plans I’ve had over the years to laser engrave a fight stick, I never actually got around to it until this week! Last week, a coworker at the library was planning on making a custom artwork label for his arcade fight stick in the library’s makerspace, and it didn’t take long discussing materials and fabrication processes (including just printing on paper to replace the stock Ryu artwork) before I practically demanded to laser engrave the hardware myself. Since I kind of stole his project from him in order to complete one of my own, I hope there’s enough juicy details herein to cover the process! Thanks, Mark!

The stock acrylic has a lip almost certainly CNC milled. These aren’t easy to recreate with a laser!

We briefly discussed engraving the acrylic panel that is included with the controller, but we decided against that so that he’d always have an unaltered panel handy. Besides, we were already talking about using a fluorescent orange acrylic that we’ve used in the library before for making bright, eye-catching tokens and trinkets. It’s a fiery equivalent to the green acrylic I use for Ingress badges; edges practically glow with this material! But the material we chose was only available in 1/8″—about 50% thicker than the stock acrylic—so I’d have to do some measurements to make sure it’d still fit. There were a few other tricky issues to figure out as well, so I knew I had some prototyping to do. But first, the design itself!

The layout is about 13″ by 8″, features eight buttons and zero button labels. Pro!

Mark had already done some of the hard work and whipped up a layout of the artwork he wanted to engrave. It was only roughly the size of the fight stick’s acrylic cover. Featuring an illustration of a kneeling samurai and seven bushido virtues, he told me he’d always been enamored with samurai and the code they lived by.

“How that warrior code and Buddhist philosophy can coexist interests me.  … I think anyone who is interested in an applicable ethic for living, who understands that the world can be violent, but hopes not to have to actually be violent, will find plenty to study in the samurai.”

The layout didn’t have accurate measurements or the button and joystick layout, though, so I’d have to see if someone put one together online. As it turns out, we didn’t need to rely on the community; late product manufacturer Mad Catz provides a PSD template for users who want to print out their own art. Its pixels are no good for laser cutting, but it has the exact dimensions and throwing together some vector circles where the PSD says they should be was quick and easy.

The chipboard prototype fit perfectly, and looks pretty snazzy on its own!

Once I had the layout prepared, I ran several prototypes. The first was cut out of cardboard, which was slightly too thick to be used easily in place of the acrylic, but it did help me discover that I accidentally nudged the bottom row of buttons out of alignment when creating the vector template. I corrected those issues and cut out a second full size prototype in chipboard. The chipboard fit perfectly and even looked pretty good under the stock acrylic!

Several small material setting prototypes. Please ignore the Triforce!

I had to run several small engraving tests on the actual material because of a few techniques I planned to use that need really precise settings. First, I’d need to recreate a lip on the entire outside rim of the acrylic; I’d have to engrave very deeply in order to do so. I also wanted to make sure I created a nice depth effect on the engraving, so I’d need to combine the halftone raster engraving on the greyscale samurai art with selective vector engraving on the darkest strokes. Finally, because of the thicker material we’re using, I wanted to round the edges so they wouldn’t stick out quite as much around the buttons. This involves pulling the laser out of focus, so I’d have to make sure the depth offset was an appropriate amount.

Detail of the letter engraving, including the deep vector stroke outlining the glyph above.

During this prototyping, I figured out that I’d need to engrave at 100% power, 10% speed to burn away enough material to recreate the stock acrylic’s outer lip. That’s ridiculously slow, and across an entire 13″ by 8″ design it would have taken over three hours to engrave, so I ended up breaking the engraving into four jobs. By doing so, I prevented the laser from passing by the entire inner area of the acrylic, reducing the engraving time to about 35 minutes. What a relief!

This acrylic really shows off fingerprints, doesn’t it?

I also determined that pulling the laser out of focus by exactly 1″ creates a nice rounded effect while being a nice easy number to remember. I used the same settings that would cut through the material with the proper focus. The slight misalignment of my #2 mirror struck again and required me to move the out-of-focus vector lines just a tiny fraction to the left to compensate. One of these days I’ll get that fixed.

My final acrylic lip was close enough, and check out that smooth rounded corner on top!

After I engraved the lip and cut out the button holes, I flipped the material, removed the back face’s protective mask, and got to engraving the art! It might not be obvious at first, but if you’re going to engrave something you’ll be resting your hands on often, you should engrave the back face and leave the top smooth and untouched. Otherwise the engraving might irritate your skin and you’re going to have to clean your filth out of the artwork more often than anyone should have to deal with. Besides, the fluorescence of the material is best shown off through the material; back face engravings capture much more of the color and appear less frosty.

Samurai on metal plate. Great shadow effect, but with plenty of distracting screws.

Amusingly enough, it didn’t dawn on me until I installed the fight stick that I’d need to make some kind of thin black background layer so that the metal button plate wouldn’t be visible through the design. It’s kind of a neat look, but it detracts from the theme, so I used the only material I had on hand (some black/silver LaserLights; don’t tell Jen!) and cut the template out of that. It fit just fine beneath the acrylic, so it was time for put Mark’s fighting game weapon of choice back together for good.

One small detail: the acrylic’s rounded corners needed to be about 0.1″ radius, quite a bit rounder than I first estimated.

The final piece was simple to install thanks to the hinged design of the FightStick-branded fight stick (that’s not confusing at all, right?). I was a little worried that the originally-pencil samurai design would suffer from being printed “in reverse” (i.e. light lines on a dark background), but the way the deeper vector engraving works with the light halftone raster engraving almost makes it look like our calm, kneeling samurai is fashioned out of fire rather than graphite. As mark put it, “Simultaneously peaceful and ready for battle.”

The joystick just barely fits between the samurai and his blade.
Detail of shallow halftone raster engraving combined with deep vector engraving.

119: Leather Twist Earrings Tutorial

Cutting leather was one of the first projects we did on the laser, way back in Week 3: Leather Cuffs.  While there really isn’t much new to say about the cutting and processing of the leather, I thought it would be fun to use some of the properties of leather (flexibility!) to make unique, laser cut earrings.  And, to make sure this post has something I’ve never done before, you’ll be getting a step by step tutorial!

Supplies Needed:

  • Leather, about 1mm thick or less.  One color, or 2 colors, whatever floats your boat.  (Pacific Leather has a great description of use by thickness of leather)
  • Leather cutting apparatus (we obviously used a laser, but Cricut machines can do it, and you could also use a simple blade or rotary cutter)
  • Ear wires
  • Jump rings (7mm or larger suggested, depending on your thickness of leather)
  • Two pairs of pliers, preferably smooth needle nose so you don’t damage the findings (ear wire and jump rings)

Step 1: Templates

Freehand paper template

For me, I actually had to make a hand cut paper version of this, just to understand the mechanics of it, and then transfer it to the computer.  I was having a little trouble envisioning the 3D-ness of the twist.  Luckily for you, I’ve done all the hard designing work for you, and you can print out this paper template.  Use it if you want to see how the mechanics of the twist works before cutting the real thing on your machine of choice, or as a guide if you are cutting by hand.

Get your earring template here!

This template is just for ONE earring.  If you want a pair, think about how you want the second earring to look.  If you’d like it to look the same, print out a second copy.  If you’d like your final earring to be mirrored (as I do), flip the template!

Step 2: Cut!

Cut your leather!  Refer back to Week 3: Leather Cuffs for specifics in laser cutting leather, and remember, it’s a sooty job.

Step 3: Twist!

What I did was make sure the holed lined up, and then gently wrapped the leather around each other. You can’t really twist like when you make paper twist – you still want the final product to lay flat.  So, a two dimensional twist, I guess.

Make sure you have two pieces where the zig zags are opposite each other
Lay one strip on top of the other.
Hold the base and gently start to wrap the pieces around each other.
Keep on twisting!
Fully twisted, holes neatly lined up on the ends.

Step 4: Fold in half!

I wanted to make the back look as nice as the front and create a little visual interest with a loop.  You can make your fold as sharp as you’d like it, or as sharp as the leather will let you.  Make sure the holes line up.

The length of twisted leather folded in half, so the ends, and all 4 holes, line up.

Step 5: Assemble!

Home made ear wire on the left, commercially made on the right, 7mm jump ring below.

Assembly can be  a touch tricky, as more commercially available ear wires have tiny loops, and will not accommodate 4 slices of leather.  I did try them on my homemade ear wires with a bigger loop, and while they did fit, they did not swing as well.  My final solution was to use a 7mm jump ring to thread through the holes on the ends of the leather strips.  This holds the dangle part together.

If you are new to jewelry making, here is a great Instructable on how to open jump rings properly.

Leather strung on the 7mm jump ring.  Ignore the fact I used a toothy pair of pliers.

To attach the ear wire and keep the earring’s orientation (aka – show the twist from the front not the loop) you have two options.  1 – put a second jump ring on to connect the ear wire to the jump ring you already have holding to leather together or 2 (my choice) – twist the loop on the ear wire so the hole is perpendicular to the hook.

Quick visual on how to twist the ear wire:

Hold the ear wire with two pairs of pliers. Make sure the pliers have a good grip on the whole loop, and the neck of the ear wire so you don’t distort the metal.
Twist the pliers in opposite directions so they are perpendicular
Wide loop is on the left, ear wire as manufactured on the right

Then open the loop like you did the jump ring and hook the jump ring on the dangle on.  Close the loop, enjoy your earring!

Step 6: Do it all again to make a pair!

How to make the alternate design on the right:

Alternate design – don’t twist! Just fold the stacked leather strips, continue on from there.
When the leather is not twisted, the strips don’t sit quite as nicely, and you can see by the bowing inside the loop. A dab of glue will fix affix it.

I hope you have fun trying this out!  You can also shake it up by only using the curvy strips, or the zig zag strips.  The design and tutorial is by Jennifer Putzier of Isette, copyright 2017, and is shared for personal use only, please!

118: Crackers

Full disclosure, guys – I did not expect this week’s experiment to work.  I figured in the worst case, it would satisfy a curiosity, and I’d get to eat hand cut homemade crackers with dip.  Ryan, on the other hand, didn’t know why I was questioning it, and thought cutting cracker dough with a laser would be a low power, simple task.  The answer was somewhere in between.

Simple ingredients, simple recipe!
Food blogging, here I come!

I’ve never made crackers before, but I had everything on hand in my bare cupboard for this recipe from The Kitchn.  As suggested, I mixed up the dough, then split it in half before rolling it out.  I took advantage of the two batches to come up with two different designs (which Ryan graciously vectorized for me.  I admittedly started this project a bit late in the evening and need help.)

Rolling it as thin as possible – the dough is springy, so you can’t work it too fast. It needs to “rest”
I layered the dough on parchment paper, and on wood.

My goal for rolling out the rough was to keep it under 3mm, 1.5 ideally.  The thinner the dough, the crispier the cracker.  I rolled it out on parchment paper – food safe, and bad things wouldn’t happen to it in the laser, just a little singeing.  I then put it on some plywood for stability, and to prevent the laser from reflecting back after it hits the honeycomb bed, which might not be the cleanest.

Pro tip: I learned when rolling out the second batch of dough that it was actually easier to roll the dough between two pieces of parchment paper when it got thin.  It was easier to flip, it seemed to spring back less, and it stayed moister while I worked with it.  I did remove the top later of parchment when I put the dough in the laser.

Test cuts – third time is the charm!  Interesting thing about cutting the dough – it was a little “sparky.”  Naturally dough isn’t homogeneous, but instead a mixture of ingredients.  The laser reacts differently to this ingredients, which created tiny little light flares.

 

Less than 3mm thick, I’m thrilled!

So, I didn’t think the laser would cut the dough at all, Ryan was thinking it would be a breeze – maybe akin to paper.  It took a few tries to get though the dough, and the right answer was some there in between – we cut at 100% power, and a slow 8% speed.  I didn’t roll it perfectly evenly, so the dough was thicker in some parts, but it still all cut.  And my test measurements were all under 3mm thick!

Heart shaped vent holes – totally a pain in the butt.

The first design was this funky hexagon shape, with little 1mm hearts cut in for venting, so the crackers wouldn’t puff.  Officially, the design is too complicated.  The outer shape is fine, but the hearts took too long to cut, and didn’t come out easily.  I actually baked the hearts in place, and then Ryan popped them out after.  And the length of time tried out the dough quite a bit since we had to have the exhaust on.  with set up, test and cutting, it was in our windy laser for about 45 minutes.  The edges of the crackers were trying to curl up!

Triangles!  Classy appearance by my phone.

Second batch we went a little more simple – a nice rounded triangle with asterisks cut for venting.  They ended up delightfully mod looking, and in were in and out of the laser in under 15.

Light toasted!

Baking is pretty straight forward, but the crackers are easy to burn as you can see.  The first batch were a little extra crisp, but edible.  The second back felt under done while they were still hot, but after they cooled they were perfectly crispy.  So, watch them closely, and make sure you let them cool, unless you are going to a crispy-chewy combo.

Midnight snack.  Homemade crackers, but I totally bought the artichoke jalapeno parmesan dip, the leftovers of which had disappeared by morning.

Verdict – The recipe was tasty but be forewarned, the crackers themselves were not airy or flaky.  They were dense, and reminded me of pita chips actually.  I may have over kneaded them.  This is a fun example of too much tool for the job – a knife easily cuts the dough.  But this would be a fun recipe to perfect for fancy dinner parties, potlucks you want to impress at, or those times you want a crunchy snack and don’t want to leave the house.

One laser, fifty-two weeks