Foam Cutter Moves Like A Hot Knife Through Butter

Make enough attempts to cut foam using whatever you’ve got — utility knife, hacksaw, serrated plastic knife — and you’ll wish hard for something that cuts cleaner, faster, and better. While there are all sorts of ways to build a hot wire foam cutter, this design from [jasonwinfieldnz] is both interesting and imitable.

If you don’t already know it, nichrome wire is nifty stuff that’s readily available in thrift store hair dryers and toasters. It stretches as it heats up, and shrinks as it cools back down.

The interesting part of this build is that instead of using a spring to keep tension on the nichrome wire, [jasonwinfieldnz] designed and 3D-printed a bow out of PLA that does the job elegantly. While [jason] was initially concerned that the bow might possibly melt, he found in practice that although the bow does get warm to the touch, it’s nowhere near hot enough to even warp.

One nice touch is the simple fence that rides along two slots and secures with wingnuts. We also like that [jason] made this foam cutter largely from scrap material, and rather than buy a spool of nichrome, he opted for a skinny heating element and pillaging the wire.

If you’re a nichrome noob, know that it doesn’t take much juice to do the job. Even though a computer power supply is what [jason] had lying around, it’s complete overkill, so you would definitely want to limit the current. Check out the build video after the break.

Still not portable enough for you? All you really need is a 18650, some nichrome, and a few bits and bobs to hold it all together.

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A Customizable Macropad To Make Anyone’s Tail Wag

[Gili Yankovitch] has always wanted some kind of macro keypad for all those boss-slaying combos he keeps up the sleeve of his wizard robe while playing WoW. Seventeen years later, he finally threw down the gauntlet and built one. But really, this is an understatement, because Paws is kind of the customizable macropad to end all customizable macropads.

This thing is completely bespoke, and yet cookie cutter at the same time — but we mean that in the best possible way. Paws can be made in any shape or form, and quite easily. How is this even possible, you ask? Well, every single key has its own microcontroller.

Yep, each key has an ATtiny85 and a cute little ribbon cable, and these form a token ring network that talks to an Arduino, which provides the keyboard interface to the computer. To make things even easier, [Gili] built a simple programming UI that automatically recognizes the configuration and number of keys, and lets the user choose the most important bit of all — the color of the LED.

[Gili] wanted to combine all the skills he’s learned since the worst timeline started in early 2020 — embedded software, CAD, electronics, and PCB design. We’d like to add networking to that list, especially since he figured out a nice workaround for the slowness of I²C and the limitations of communication between the ‘tiny85s and the Arduino. Though [Gili] may have started out with a tall order, he definitely filled it. Want to get your paws on the design files? Just claw your way over to GitHub.

If your customization interests lie more toward what program is in focus, be sure to check out Keybon, which was one of the many awesome winners of our Odd Inputs and Peculiar Peripherals contest.

OpenJewelry, No Pliers Required

They say that if you want something done right, you gotta do it yourself. Oftentimes, that goes double for getting something done at all. Whereas some people might simply lament the lack of a (stable) Thingiverse-type site for, say, jewelry designs, those people aren’t Hackaday’s own [Adam Zeloof]. With nowhere to share designs among engineering-oriented friends, [Adam] took the initiative and created OpenJewelry, a site for posting open-source jewelry and wearable art designs as well as knowledge about techniques, materials, and processes.

[Adam] has seeded the site with a handful of his own beautiful designs, which run the gamut from traditional silversmithing techniques to 3D printing to fancy PCBs with working blinkenlights. You really should check it out, and definitely consider contributing.

Even if you don’t have any jewelry designs to share, the code is open as well, or you could even edit the wiki. Just be sure to read through the contribution guidelines first. If you don’t have the time for any of that, donations are welcome as well to help maintain the site.

We love wearable art around here, especially when it serves another purpose like this UV-sensing talisman, or this air quality necklace.

Teardown: How Many Teddy Ruxpins Does It Take To Start A Coven?

Well, I did it. I conquered my childhood fear of talking bears and brought a vintage Teddy Ruxpin animatronic stuffed bear into my home. There were and still are plenty of his brethren both young and old to choose from on the auction sites, and when I saw this particularly carefree barefoot Teddy in his Hawaiian shirt and no pants, I was almost totally disarmed. Plus, the description promised a semi-working unit with a distorted voice, and who among us could resist a specimen in such condition? Maybe the tape deck motor is going out, or it just needs a new belt. Maybe the tape itself messed up, and Teddy is fine. I had to find out.

But let me back up a bit. If you don’t know what I’m talking about, Teddy Ruxpin was a revolutionary toy that dropped in 1985. It’s a talking teddy bear that reads stories aloud, all the while moving his eyes and mouth to the sounds. Along with Teddy came special cassette tapes, corresponding story books, and outfits. I wanted one when I was a kid, but was also kind of scared of them. Since they were so expensive — about $250 inflation-adjusted for the bear and a single tape / book / outfit, plus another $15 for four D cells — I never did get one in my youth.

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Hackaday Podcast 177: Microscopes, Telescopes, Telephonoscopes, And A Keyboardoscope?

This week, Editor-in-Chief Elliot Williams and Assignments Editor Kristina Panos stood around talking like they weren’t thousands of miles apart. And we mean that literally: Kristina just got an up/down desk, and it turns out that Elliot’s had the exact same one for years.

Kristina’s phone is heavier than yours.

In between the hammerings on Kristina’s house (she’s getting new siding), we kick things off by drooling over the first images from the James Webb Space Telescope, and compare a few of them to the same shots from Hubble.

We managed to save a bit of saliva for all the seriously swell keyboards and not-keyboards we saw throughout the Odd Inputs and Peculiar Peripherals contest, all of which are winners in our book.

This week, we ask the tough questions, like why would someone who has never played guitar want to build one from scratch? We can only guess that the answer is simply, ‘because l can’. As lazy as that reasoning may sound, this build is anything but.

Later on, we’ll ogle an ocean of PS/2 keyboards and their new owner’s portable testing rig, complain about ASMR, and laugh about a giant nose that sneezes out sanitizer.

Direct download. And burn it to CD-RW!

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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Style Your Tile With 3D Printed Countertops

We’re all familiar with supply chain issues as they relate to chips and DIPs, but anyone who has requested an estimate for home improvements lately knows that the problems extend to things like plywood, and probably tile, marble, and Formica. Faced with adversity when it came to renovating the kitchen, [3DPC] decided to have a go at 3D printing custom countertops instead of buying tile.

Always build a testing rig first! Polyurethane looked great when wet, but resin was the clear winner.

Since grout isn’t required here but is ultimately expected, [3DPC] beveled the edges of the tiles in order to allow for decorative ‘grout’ filler pieces that provide a nice contrast. That high-gloss shine comes from a combination of printing onto glass, the direction of the layer lines, and the resin sealer that [3DPC] hired a professional to pour. Because of these factors, the tiles have an increased transparency that makes them look super cool. Be sure to check out the brief build video after the break.

To be fair, this is not [3DPC]’s first 3D-printed home-improvement rodeo — he has already saved tens of thousands of dollars by printing instead of purchasing. For this particular project, [3DPC] calculated a total cost under $400 —  a fraction of what a professionally installed countertop would have cost. We wonder how much he’ll save on tiling the bathroom, which is already in progress. We can’t wait to see it!

Are you still without a printer? Might as well make one that can use trash. Or if you already have a printer, just make filament from recycled plastic. It’s all here among the 2022 Hackaday Prize Round 2 winners; just let your imagination wander.

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Chinese Anti-Porn Helmet Raises Eyebrows, Questions

Did you know that pornography is completely illegal in China? Probably not surprising news, though, right? The country has already put measures in place to scour the Internet in search of explicit content, mostly using AI. But the government also employs human porn appraisers, called jian huang shi, whose job it is to judge images and videos to decide whether they contain explicit content. Also probably not surprising is that humans are better than AI at knowing porn when they see it — or at least, they are faster at identifying it. Weirdness and morality and everything else aside, these jian huang shi are regular people, and frankly, they get exhausted looking at this stuff all day.

So what is the answer to burnout in this particular field? Researchers at Beijing Jiaotong University have come up with a way to bring the technological and human aspects of their existing efforts together. They’ve created a helmet that can detect particular spikes in brainwaves that occur from exposure to explicit imagery. Basically, it flashes a combination of naughty and ho-hum images in rapid succession until a spike is detected, then it flags the offending image.

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