December 2020-Laser Engraving with A Graphing Calculator!

Have you ever needed a way to impress your math teacher with a unique work of art? Are you tired of doing your Calc homework, but still want a way to feel like you are doing math? Do you want to combine all this with your laser engraver? If so, read on!

What we will be making today.

If you're like myself, you've probably once gotten trapped in the endless rabbit hole of making designs with Desmos. This is a popular web-based graphing calculator that is (thankfully) replacing the Ti-Nspire as students' graphing calculator of choice. Compared to the Nspire, not only is Desmos free, but it is sleeker, faster, easier to use, and doesn't feel like it was coded during the same time when my dad was learning Fortran. Along with solving/visualizing equations Desmos can make a lot of cool, aesthetically pleasing designs out of equations:

A design for my Calc BC teacher, made out of equations.

Now, the cool part about designing with a graphing calculator is that every single line/curve/point you plot is represented in, well, a graph. This means that it is fundamentally similar to a vector image, which is the same type of image many laser engravers use (or can be easily converted into a type that works). See my last post if you are unsure about how this exactly works.

Indeed, a Desmos graph can be easily exported to a .svg file, a type that can be imported into Inkscape (a design software) for laser engraving. The documentation on how to do this is a bit shaky, so let's take a look at how I prepared a design for laser engraving a competition entry.

The prompt for the digital art competition was to design a "math sheep".

After designing your work in any web browser that works with Desmos, save it to your account, and open it in Firefox. While in Firefox, install the Greasemonkey extension. Once complete, press the Greasemonkey icon in the top right corner and click "new user script":

You should now be given a screen that looks like this:

Copy and paste this file into the unnamed script and press the save button on the upper left corner. Credit to baz1 on GitHub.

This should work!

Now, when you refresh Desmos, you should see a "Get SVG" button on the top left. Before pressing it to download your .svg, unselect the "Grid", "Arrows", "X-Axis", and "Y-Axis" buttons in settings.

When the .svg is downloaded, know that (with my setup) it WILL NOT AUTOMATICALLY BE RECOGNIZED BY THE COMPUTER AS A .SVG. You can fix this by renaming it as anything with ".svg" to the end of the file's name.

Renaming the file from the default u7skVC33 to u7skVC33.svg

With the bug fixed the file can now be opened with Inkscape:

We're in!

After resizing and a few additional modifications, you should be able to laser engrave what you designed with Desmos!

Some adjusting and engraving later... and it looks great!

December 2020-Evolution of my Work

It's been a long time since I last made a significant post to this blog. Probably because it's called Adat is Bored and not Adam Has Stuff to do, but now that hazing my finals are over it's no longer the case. I have no more homework, and it's time for another post!

I've been surprised by the high quality artwork I've been able to produce with the laser engraver. When I started my project of converting a broken 3D printer into one, I thought that I would not be able to make anything that aesthetically pleasing because of limitations given by 3D printing. Indeed, I will boldly state that, as much as I love 3D printing, nothing produced by 3D printers is particularly beautiful. 3D printers have a lot of quality problems--the surface of everything they make is uneven and porous, and the plastic is prone to warping and containing many weird scars from being built in layers. Although these issues can technically be fixed with post processing, it's a huge pain and still leaves the print with a crappy McDonald's toy-like aesthetic.

A 3D printed Gromit (from Wallace and Gromit) I made as a Secret Santa present. Design credit to Stevie135 on Thingiverse. Despite being made on a "high quality printer," if you zoom in you can see scars and "layer lines" made from the layers being stacked on top of each other. You can also see scars from the supports being ripped of :(

To sum up my expectations when I started this project: they were not high. I thought all the crappy parts that went into my homebrew engraver would indeed return, well, crappy engravings. However, I've been pleasantly surprised by how wrong I was. Although operating this engraver is much less streamlined compared to others--such as my college's powerful Epilog Fusion Pro--I've been impressed by the quality of art I've been able to produce. Instead of churning out McDonald's toys like it used to when it was a 3D printer, my engraver now produces balsa wood pieces with a really unique aesthetic. I'd describe it as natural, as it's made of wood, but also clean and industrial with the micron-level accuracy of the machine. The dark parts that are engraved contrast beautifully with the rest of the wood piece, and are relaxing to the eye. It's what got me hooked on engraving and making more art: how I can finally make pieces that I find beautiful, and have fun while doing it.

An image engraved of my friend. Designed by scanning a drawing of him, letting Inkscape trace it, and sending it to the engraver.

Experimentation in laser engraving photos of animals by using a computer to trace the photo. ZsaZsa the cat, everyone!

An homage made to an elusive member of the Case Western Reserve University 2024 Discord Server. Arranged in Inkscape with different photos and fonts.

For us university students, this unfortunately does not require any explanation.

After engraving pixel-based photos by simply popping them into my software, having Inkscape's "trace bitmap feature" convert them to vector art, and calling it a day, I got a bit restless. I wanted to have more creative control over things I was making. However, there is an issue with this: I'm not the best artist and struggle with drawing/designing things from my imagination. In other words, I need a pretty good reference image for the art I make.

My first project with laser engraving things I draw was inspired by the #toonme challenge. It's basically when you take a photo of yourself, or others, or anything really, and draw half of it (traditionally as a cartoon) while leaving the other half blank. I traced half a photo of myself for a graphic design class, and had a lot of fun with it.

My first #toonme designed in Procreate.

Over the summer I re-did this project, only with laser engraving half of the photo instead of drawing it:

My #toonme--half laser engraved, of course.

Although I had a lot of fun with the laser engraved #toonme, it had a pretty big issue that does not normally pop up in the graphic design world. That is, issues in image path tracing improperly defining the photos, and therefore not letting me engrave them as intended. In other words, the engraver can only engrave vector art "paths," a series of lines and points mathematically defined in a given plane. When we want to convert between a pixel based image to a vector image, we take the pixel based image and let the computer trace it. Let's take a look at what this means by using Inkscape, a program for vector based graphic design. First, we can draw a simple straight line, or "path," in Inkspace. Because this is a single path, when engraved it will only look like a simple line:

A thick path drawn using the "create paths" feature in Inkscape. It is important to note that this shape has no fill, but a black stroke color.

Next, screenshot the path you just drew, which will automatically convert it from being vector based to pixel-based. Paste the screenshot back into Inkscape, and use the "trace bitmap" feature to convert the screenshot back into a vector image. You can do this by selecting the image, then selecting path<trace bitmap. Default configurations should work.

A screenshot of the line above, pasted back into Inkscape. Trace it by pressing "path" (highlighted in red) then "trace bitmap".

Once this is complete, both of the lines drawn should look identical to each other in Inkscape. In theory, when you laser engrave them, they should also look the same:

Comparing the thick path drawn in Inkscape (left) to the screenshot of it that was traced by Inkscape (right). They look identical!

Let's engrave the exact image above and see what happens:

The two lines and text, engraved.

Uh oh! They look different! Now we can see the issue: when Inkscape traces any line, it will not show it as a single path even when you want it to. It will always define a line as a collection of paths, like in the "line" on the right. Because the engraver will only engrave paths (and doesn't care about their width), it will therefore show what is supposed to be as a single line as an awkward rectangle.

Under closer inspection, we can see how this happened in Inkscape. Select "no fill" for the line on the right (but make sure that "stroke paint" is set to a color) and notice how it's not actually a single path:

Notice how the line on the right is not a line at all--it is made up of a collection of four paths, each of which the engraver will engrave.

This awkward effect is how my self-portrait was messed up. I originally did all the artwork in Procreate--a great app used for pixel-based drawing on an iPad. This means that when you draw anything with the app, it will be made out of pixels. Here's what part of the laser engraved image looked like before it was traced:

The pixel-based Procreate image before engraving

Here's what the same part of the image looked like after it was traced by Inkscape and engraved:

The pixel-based image, but traced and engraved. Notice how the checkerboard flannel pattern does not come out cleanly, since it was traced wrong by Inkscape

It's important to note that not all laser engravers have this issue, however most budget ones and ones made from modified 3D printers/CNCs will. The solution to this issue required me to not trace images in Procreate, but trace them in Inkpad, a different iPad app. Inkpad is similar to procreate except for it uses a vector file format instead of a pixel based file format. Therefore, when using it there is no need for converting the art one traces to a vector format using a computer.

Take a look at an example below for how I trace. Let's start off with the album covers for one of my favorite artists, Jeff Lynne:

From Out Of Nowhere album cover. Source: Consequence of Sound

Then, trace over it by hand with an Apple Pencil in Inkpad. Pay attention to changes in shape and other edges, but (generally) don't engrave changes in color or shadows as they will not show up well in the engraved wood. Also, make sure to lock the source image as its own layer, and trace over in a layer above it. When complete, this is what my work looked like:

The paths I traced (in white) over the original discovery saucer photo.

The image when it was complete!

Once the traced wireframe-like image is in Inkpad, it can be exported to vector files ubiquitously used in laser engraving. Here is what the piece of wood looked like when engraved on my college's Epilog Fusion Pro:

The final product!

I made other pieces using the same method on the laser engraver I built:

This was from when Elon Musk launched his Tesla into space. Source photo taken from the livestream from the car itself.

Another album cover, Plastic Beach by Gorrilaz.

Thanks so much for making it this far! More to come soon with other experimental laser art!

December 2020-I'm Back!

You heard it! Time for some updates: when I last posted I finished with converting a 3D printer to a relatively conventional laser engraver, and had plans to turn it into an Etch-A-Sketch laser engraver. That is, you could control the engraver with knobs like you would an Etch-A-Sketch. It was completed! Although this second transformation was a bit of a pain--the rotary encoders in the Raspberry Pi were unstable and the low wattage of the laser module I used required it to move realllllllllly slow, it was still a lot of fun. See below for some of my work engraved in "Etch-A-Sketch" mode instead of being engraved using computer-generated commands (which is more conventional):

My most successful piece with the Etch-A-Sketch laser engraver. It says "Hippo" with a picture of a Hippo I tried to sketch on a hard book cover. It looks like a cow from Minecraft.

After a long night of debugging, I engraved "Overrated" into a piece of balsa wood.

When I get around to it, I will publish the source code in python for the Etch-A-Sketch laser engraver. I'll also probably post a demo to YouTube. I don't think there is that big of a rush to do this as my exact type of setup is already a bit obsolete, with some of the necessary modifications made on my 3D printer not being around anymore.

The two rotary encoders that let the user control the engraver like an Etch-A-Sketch. 

Despite my struggles with unconventional modifications, I highly recommend turning any broken 3D printer into a laser engraver. Because (in my opinion) the most likely part to break in a printer is the extruder (the part that spits out plastic), the printer may not have control over the necessary and complicated instrumentation, heating equipment, or motors for printing. However, In a laser engraver these parts are irrelevant. All you need is a functioning cooling fan port in the motherboard (where the laser gets its power from), a functioning motor that controls the position of the extruder, and you should be good to go! It is a great way to give an otherwise broken machine a second life. Laser modules that can be attached to the printer are very cheap off Banggood, if you get one of them with a quality pair of safety glasses it can be a lot of fun!

Expect a much longer post in the very near future about some of the other work I've done with the engraver over my summer break and since I returned home. Thanks for making it this far!