Tag Archives: video games

14: Box Joints

I’ve done box joints before, just once, for a 3D picture frame celebrating a newborn baby. It was a harrowing experience back then because I didn’t really understand how the width of the laser beam affects the ability of two pieces to fit together and because I was using a thick wood that just didn’t want to play nicely. The piece did turn out fine, but the procedure was such a mess that I haven’t really considered box joints since.

Three tetriminos with etched surfaces.
Three tetriminos with etched surfaces.

That changed this week, because Tetris was still on my mind. At some point while laying out hundreds of tiny tetriminos for the NES etching project I realized that it shouldn’t be too hard to recreate those popular shapes in 3D if I could just get over my box joint demons. Wood was out; I selected varying colors of 1/8″ thick acrylic for my material this time.

The darker shapes were the tricky ones.
The Blue J / Orange L. The darker shapes were the tricky ones.

Figuring out the shapes initially took no time at all.  I settled on 1″ squares to form the basic tetrimino shapes and made sure that the box joints (the teeth shown above) were the same thickness as the material, 1/8″. When I began on the Cyan I, there were no inside corners and the design went incredibly smoothly. Because Yellow O, unpictured, is just a fatter version of the same shape, adjusting the cut was trivial.

When I got around to Blue J and Orange L, I had to get through a few bad test cuts before figuring out how to adjust two shapes to account for the inner corner. Once I discovered how it should be shaped, the same inner corner treatment could be applied to Red Z (shown here) and Green S, as well as the unpictured Purple T.

The trickiest part of layout was the inside seam shown here at center.
The trickiest part of layout was the inside seam shown here at center.

With that design puzzle solved, more test cuts were spent discovering the best kerf setting for this material. After cutting a few box-jointed pieces that wouldn’t fit together and a few that fit together so loosely they’d require glue, I discovered that the laser’s width burned away 0.0064″ of material on each line, which could be solved with an offset path setting of 0.0032″. The resulting graveyard of pieces shows many cracked edges, but the final pieces fit together so perfectly that they’ll never fall apart by accident.

The graveyard: Paper unpeeled, incorrect shapes and cracked joints.
The graveyard: Paper unpeeled, incorrect shapes and cracked joints.
The difference between Orange L and Blue J here is paper: lots and lots of tiny paper tetriminos.
The difference between Orange L and Blue J here is paper: lots and lots of tiny paper tetriminos.

Speaking of accidents and graveyards, don’t soak transfer paper in Goo Gone. One of the fun little extra steps I took during this weekly project was to vector etch a pattern of tiny tetriminos over top of these big 3D pieces. Well, when you vector etch a sheet of acrylic that is covered with transfer paper to prevent burn issues, you end up with hundreds of tiny little paper shapes you then have to remove by hand; you can see them here in the comparison between Orange L and Blue JI thought I’d save time by liberally applying Goo Gone to the paper surfaces and then leaving the pieces overnight. I figured I should be able to just wipe away the paper, its adhesive dissolved.

This gelatinous goop is an incredible pain to remove.
This gelatinous goop is an incredible pain to remove.

The end result was horrific: the Goo Gone did make the paper very easy to remove, but it left the adhesive on the acrylic, which had become a horrible, gummy mess. Way too much time was spent using more Goo Gone, some isopropyl alcohol, and some plain liquid soap to slowly remove the residue from the etched pieces. What a mess.

The Cyan I, everyone's favorite tetrimino.
The Cyan I, everyone’s favorite tetrimino.

Most of my tetriminos were cut out of transparent colored acrylic, though some pieces (shown in the graveyard pictures) were opaque. The Cyan I was the most fun to look at, thanks to the “Ice Blue” acrylic used. It didn’t have much visible color looking at the surface of the material, but the cyan color really shines through the etches and cut edges. It appears to glow, even when placed next to the other transparent tetriminos.

 

 

Plenty of tetriminos stacked in ways they shouldn't be stacked.
Plenty of tetriminos stacked in ways they shouldn’t be stacked.

 

10: Tiny Things

A few weeks ago, I was planning to visit an artist friend of mine and wanted to bring something laser-made to show off. I settled on some very small, very fine etched-wood versions of some of his recent grayscale artings. Making the art look good on the surface was tricky, and while I had a feeling this would lead into a 52lasers project, I didn’t get pictures before I left.

Tiny wooden Bookman and Gotham vie for attention!
Tiny wooden Bookman and Gotham vie for attention!
I used this amazing loupe (thank you, Mom!) to inspect the finished pieces.
I used this amazing loupe (thank you, Mom!) to inspect the finished pieces.

Oh well! This week, I decided to give micro engraving another try! As part of Abecediary (game and typography stuff!) I have several square alphabet designs made; they are highly detailed shapes that proved to be great initial tests. The feature I really wanted to test with this project was the highest available Image Density as described in the Laser Interface+ software. While I usually etch things at an entirely respectable setting of 5, cranking it up to 7 offers a much higher amount of lines per inch. It takes much more time and is often overkill unless you’re etching incredibly fine detail into small things. Funny, that’s exactly what I’m trying to do!

Nice view! You can see how the etch ran counter to the woodgrain.
Nice view! You can see how the etch ran counter to the woodgrain.

While it’s hard to see in the wooden pieces (cut from the same lightly finished wood I cut the Triforce lapel pins from), the few abecediaries that were cut out of acrylic gave away an issue that I didn’t even realize until I took some nearly-macro photographs. If you don’t have an appropriate Universal Tuning setting, your etched lines will look interlaced. This happens because every line etched leftward is slightly off from every line etched rightward. This issue manifests as slightly zigzaggy vertical lines in designs, and when the setting is really off, you can end up with design elements that look like they’ve been duplicated side-to-side, almost certainly ruining the designer’s original intent.

The four miniature abecediaries all stacked up nice.
The four miniature abecediaries all stacked up nice.
You can see how the laser cut outline dug into the C a little bit.
You can see how the laser cut outline dug into the C a little bit.

Another mishap eagle eyes will spot is the incorrect kerf adjustment. I regularly create an offset path of about .05″ in order to account for the laser’s width. For these positively tiny applications the laser’s width is relatively much more significant, and I can see now that there should have been more space offset so that the outline cut didn’t dig into the letters as much, especially compared to the tighter inside etching.

This Mario is tiny! He's only about 4mm across.
This Mario is tiny! He’s only about 4mm across.

I’m a Nintendo kid at heart, and while the SNES still holds the top spot in “greatest video game consoles ever” for me, the NES is where I spent my single-digits, and it’s easily my nostalgia weak point. I’ve got quite a few NES-related things planned out for future projects, but for this micro-engraving job, I took a few cartridge scans—only edited to black and white and contrast adjustments—and shrank them down to under an inch wide.  One trace-job later for the outer cut and I had my very own tiny little Game Paks.

A row of SMB3 copies. I feel like I'm in a rental store again.
A row of SMB3 copies. I feel like I’m in a rental store again.

These were difficult. The halftone feature of my laser hardware got sloppy when I maxed out the density and used a grayscale photograph to etch from. In the first attempt, not photographed, the rubbing alcohol I use to clean lasered materials ate away what was left of the black cap immediately, leaving me with a tiny little pure-white copy of Super Mario Bros. 3. Several additional cuts at various universal tuning settings gave me many copies of that game, but there was another material that Jennifer really wanted me to use for a tiny NES cart.

Three different Legends of Zelda.
Three different Legends of Zelda.

Thus, micro Zelda was born! The messiness of the etching is unfortunate, and I had to adjust the relative brightness of certain elements quite a few times to get results that vaguely resembled the original cartridge. Still, these are so much fun to look at with a nice shiny light nearby that I feel I’m going to have to revisit the miniature Zelda cartridge after I can spend some real design time on one rather than using a Google Image-sourced cartridge scan.

My understanding of the limitations of the 2.0 laser lens suggests I could invest in a collimator and a High Power Density Focusing Optics lens to get better fine etching results. Maybe some day!

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