The Deadliest Project On The Internet?

May 2, 2022 by Ryan Flowers 96 Comments

Before deciding whether the headline of this article is clickbait, please take a moment to watch the excellent video by [BigClive] below the break. And then, go to your local search engine and search the phrase “fractal burning death”. We’ll wait.

With that out of the way, we have to admit that when we saw the subject “The most deadly project on the Internet” on [bigclivedotcom]’s YouTube channel, we were a bit skeptical. It’s a big claim. But then we watched the video and did some googling. Sadly, there are over 30 documented cases of this project killing people, and more cases of permanent grievous injury.

The results of Fractal Wood Burning with High Voltage

Fractal Burning is a hobby where wood is burned by slathering wood in a conductive slurry and then applying high voltage to either side of the wood, usually using something not rated for high voltage, such as jumper cables. The High Voltage is supplied by an unmodified Microwave Oven Transformer. Other projects using MOT’s typically rip out the high voltage secondary windings and re-wind them as low voltage, high amperage transformers, and are using in Spot Welders and even arc welders.

As laid out by [BigClive], the voltages coming from an unmodified MOT, ranging from 2-3 KV (That’s between two and three thousand Volts) at a very low impedance are right up there in the “Don’t go near it!” territory.

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Building An Edge Lit Sign From The Scrap Pile

April 22, 2022 by Tom Nardi 3 Comments

Whether in a shop window or mounted to the top of consoles in NASA’s Mission Control Center, edge lit acrylic is a popular choice for making high visibility signs. Partly because of their striking hologram-like appearance, but also because they’re exceptionally cheap and easy to produce. Just how cheap and easy? Take a look at this recent video from [Hack Modular] for a perfect example.

Now you might think you’d need something like a CNC router to produce a sign like this, and for more complex images, that’s arguably the case. But if you’re only concerned with text, and have a fairly steady hand, you can pull off the etching step with nothing more exotic than a printed template and a razor blade. Of course, the LCD style font that [Hack Modular] picked for this sign is particularly well suited to hand cutting — if you’re interested in edge lit calligraphy, this method probably isn’t what you’re looking for.

This linear LED provides a more consistent light.

With the text carved into the acrylic, the only missing ingredient is light. For that, [Hack Modular] is using a 12 volt linear LED strip light. That is, instead of being dotted with individual LEDs like traditional strips, it provides a continuous band of light that’s perfect for this application. That gets stuck down to a scrap piece of wood, and a rusty angle bracket from an old Meccano set is used to hold the acrylic right on the center-line. If you think the final product looks like something that was created from trash, don’t feel bad, that was the intent.

The end result looks great. In fact, if we’re being honest, it’s a lot better than we would have thought was possible using hand tools. Granted the choice of font has a lot to do with that, but then again, we wouldn’t mind if all our edge lit acrylic signs ended up looking like big seven-segment displays either.

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The octagonal wooden box described in the project. On the left, outer surface of the box is shown, with "Say Friend And Come In" inscription, as well as a few draings (presumably from Lord of The Rings) and two metallic color stars that happen to serve as capacitative sensor electrodes. On the right, underside of the lid is shown, with all the electronics involved glued into CNC-machined channels.

Say Friend And Have This Box Open For You

March 28, 2022 by Arya Voronova 13 Comments

Handcrafted gifts are special, and this one’s no exception. [John Pender] made a Tolkien-inspired box for his son and shared the details with us on Hackaday.io. This one-of-a-kind handcrafted box fulfills one role and does it perfectly – just like with the Doors of Durin, you have to say ‘friend’ in Elvish, and the box shall unlock for you.

This box, carefully engraved and with attention paid to its surface finish, stands on its own as a gift. However, with the voice recognition function, it’s a project complicated enough to cover quite a few fields at once – woodworking, electronics, and software. The electronics are laid out in CNC-machined channels, and LED strips illuminate the “Say Friend And Come In” inscriptions once the box is ready to listen. If you’re wondering how the unlocking process works, the video embedded below shows it all.

Two solenoids keep the lid locked, and in its center is a Pi Zero, the brains of the operation. With small batteries and a power-hungry board, power management is a bit intricate. Two capacitive sensors and a small power management device are always powered up. When both of the sensors are touched, a power switch module from Pololu wakes the Pi up. It, in turn, takes its sweet time, as fully-fledged Linux boards do, and lights up the LED strip once it’s listening.

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Thermal printer with a loop of thermochromic foil inserted in it, printing digits of Pi on the loop.The digits gradually disappear from the foil as it exits the printer.

Celebrating The Infinity Of Pi Day With Thermochromic Foil

March 21, 2022 by Arya Voronova 8 Comments

It might take you some time to understand what’s happening in the video that Hackaday alum [Moritz Sivers] shared with us. This is [Moritz]’s contribution for this year’s Pi Day – a machine that shows digits of Pi in a (technically, not quite) infinite loop, and shows us a neat trick we wouldn’t have thought of.

The two main elements of this machine are a looped piece of thermochromic foil and a thermal printer. As digits are marked on the foil by the printer’s heating element, they’re visible for a few seconds until the foil disappears from the view, only to be eventually looped back and thermally embossed anew. The “Pi digits calculation” part is offloaded to Google’s pi.delivery service, a π-as-a-Service endpoint that will stream up to 50 trillion first digits of Pi in case you ever need them – an ESP8266 dutifully fetches the digits and sends them off to the thermal printer.

This machine could print the digits until something breaks or the trillions of digits available run out, and is an appropriate tribute to the infinite nature of Pi, a number we all have no choice but to fundamentally respect. A few days ago, we’ve shown a similar Pi Day tribute, albeit a more self-sufficient one – an Arduino calculating and printing digits of Pi on a character display! We could’ve been celebrating this day for millennia, if Archimedes could just count a little better.

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A Fractal Papercraft Tree

March 20, 2022 by Jenny List 15 Comments

Sometimes there are projects that we introduce with a bit of context, some background, and other times as with [RayP2]’s fractal papercraft tree, we introduce them simply because they are beautiful.

It’s a deceptively simple design of a repeating pattern of the same shape getting ever smaller with each iteration, and terminating in a tetrahedron with branches from each of its faces. It’s not origami, instead it’s a cut-and-glue design, and its construction is a surprisingly involved affair with some lateral thinking required to bend the tabs on the smaller branches. The design was first prototyped with plain paper, before a final version was made with card stock. The part that makes it exceptional is that he used shiny gold card stock with the gold side on the inside, meaning that when lit from the trunk the end of each branch glows attractively. Fitting the light required a modification to the trunk design, but this doesn’t take away from the whole.

The result is an attractive sculpture, a talking point, and something with a mathematical angle to boot, which we like. It’s certainly not been the first papercraft ptoject we’ve shown you, though perhaps these paper retrocomputers are a little less artistic.

3D Printed Molds For Casting Rose’s Metal

March 17, 2022 by Kristina Panos 22 Comments

Have you ever played with Rose’s metal? It’s a fusible alloy of bismuth, lead, and tin with a low melting point of around 100 °C. Historically, it’s been used as a solder for cast iron railings and things, and as a malleable pipe filler material to prevent crimping while a pipe is bent.

[Ben Healey] has been playing around with Rose’s metal and some PETG printed molds, making everything from Star Wars Imperial credits to chess pieces to leather stamping tools. In the video after the break, [Ben] takes us through the process, beginning with mold-making from STLs — something he picked up from another YouTuber.

He recommends adding registration marks to multi-part molds in order to keep everything lined up, and adding a small recess in the seam for easy separation with a flat-head screwdriver. So far, the molds have held up to multiple pours, though [Ben] did print them rather thick and is glad he did.

As far as making liquid metal, [Ben] used a cast iron pot with a convenient pour spout, and a blowtorch. He added graphite powder to the molds in an effort to make them give up the goods more easily. To finish the pieces, [Ben] cut the flashing with tin snips and used sandpaper and a Dremel to smooth the edges. Copper plating didn’t work out, but [Ben] is going to try it again because he thinks he screwed something up in the process. He’s also going to try printing with TPU, which we were just about to recommend for its flexibility.

There are many ways to cast metal on the (relatively) cheap. Have you considered Kinetic Sand?

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How To Make Laser-cut Decals On The Cheap

March 12, 2022 by Donald Papp 13 Comments

Want to make a sweet adhesive decal with a complex design and floating elements, but all you have is a laser cutter and some tape? Good news, because that’s all you need with this method of creating adhesive tape decals on a laser cutter demonstrated by the folks at [Lasers Over Los Angeles]. The overall technique is very similar to creating vinyl decals and using tape transfer to apply them, but is geared towards laser cutters and nice, cheap tape.

This method also makes applying to non-flat surfaces a breeze.

The way it works is this: paper-based tape (such as blue painter’s tape) is laid down in strips on the laser cutter’s honeycomb bed, forming a nice big rectangle big enough for the intended design. Then, the laser cutter cuts vector art into the tape, resulting in an adhesive decal ready to be stuck to some other surface. Transferring is done by using good quality clear packing tape to “pick up” the decal, then move it to where it needs to be.

To do this, one lays strips of packing tape onto the top of the design on the laser bed, then lifts the design up and away. Move the design to its destination (the clear packing tape helps in eyeballing the final position), press the decal onto the final surface, and carefully peel away the clear packing tape. This works because the packing tape sticks only weakly to the back of the painter’s tape; it’s a strong enough bond to hold the decal, but weak enough that the decal will stick to a surface even better.

It’s true that painter’s tape isn’t as durable as vinyl and the color selection is a bit limited, but design-wise one can go as big as the laser bed allows, and the price is certainly right. Plus it’s easily cut by even the most anemic of diode lasers.

Speaking of desktop vinyl cutters, they may have small working areas compared to most laser cutters, but they have some fantastic workshop applications. They can even do home PCB fabrication, by way of knocking out three essential pieces: the etching mask, solder mask, and solder stencil.