Author: Zoe Skyforest

3611 Articles

DIY Electrolysis Machine Removes Hair Permanently

May 7, 2026 by 38 Comments

If you talk to the FDA, there’s only one permanent method of hair removal—electrolysis. This involves sticking a needle into a hair follicle, getting it very hot or running a current through it, and then letting heat and/or the lye generated kill the root of the hair dead. Normally, you’d pay someone with a commercial machine to do this for you at great expense. Or, you could do it yourself with a home-built machine, as [n3tcat] did.

Based on the available information out in the wild, [n3tcat] decided to build a galvanic electrolysis machine. This specifically passes current through a needle in the hair follicle to generate lye at the hair bulb, which kills it. The amount of lye generated depends on the amount of current and the time over which it is applied. More lye is more likely to kill a follicle permanently, though there are limits with regards to avoiding scarring, other skin damage, and excessive pain.

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How Giant Tanks Of Fluid Could Help Support The Power Grid

May 5, 2026 by 67 Comments

If you’ve been paying any attention to the renewable energy space, you’ll know that generation isn’t really the problem anymore. Solar panels are cheap, and wind turbines are everywhere. The problem is matching generation with demand—sometimes there’s too much wind and sun, and sometimes there’s not enough. Ideally, you could store that energy somewhere, and deploy it when you need it.

The answer everyone keeps reaching for is lithium-ion batteries, and they work just fine. However, there’s a competing technology that’s been quietly scaling up in the background—the vanadium flow battery. It has some unique advantages that could see it rise to prominence in the world of large-scale grid storage.

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Camera Slider: Build Instead Of Buy Goes Awry

May 4, 2026 by 1 Comment

[TheHyperFix] had a problem. He’d spied a brilliant camera slider, but didn’t want to lay out big money to acquire it. The natural solution? Build one! Only, life is seldom so straightforward.

The plan was straightforward – take an old broken 3D printer, and repurpose its parts to make a camera slider instead. The build started with a aluminium extrusion, some V-slot wheels, and a 3D printed platform to hold the camera. Moving the platform was done via a belt drive, using the stepper motors and some software to tell the original printer controller what to do.

Unfortunately, the early experiments failed when the controller blew up under load. An Arduino was subbed in with a CNC shield, which got things back on track, and [TheHyperFix] had a somewhat functional slider with relatively jerky movement. A tough iterative design process ensued to work out problems with bearings and the Arduino’s pulse limit, among others.

As it stands, the slider is semi-functional, but it’s not quite well behaved enough to use for professional shooting. Still, for a first attempt at electronics prototyping, we think [TheHyperFix] did a pretty solid job. It might not be all there yet, but it’s well on the way, and a great deal was learned in the process.

If you’re trying to build a camera slider in a hurry, you might like to try recreating one of the builds we’ve featured before. Video after the break.

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Why Leaded Fuel Is Still A Thing

May 4, 2026 by 100 Comments

Leaded fuel is considered one of the greatest environmental failures in modern human history. Adding tetraethyl lead to gasoline reduced knock in internal combustion engines, which was widely considered a good thing. It was only later that the deleterious health effects came into view, by which point there was a massive fleet of lead-dependent automobiles and an industry reluctant to change. Still, the tide turned, and over the last 50 years, unleaded fuel has become the norm for automotive use across the world.

And yet, there remains a hold out—a world where engines still burn leaded fuels and spray their noxious fumes across the countryside. In the aviation sector, leaded fuel remains a normal part of everyday operations to this day amidst concerted efforts to eliminate it for good.

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TagTinker Lets You Hack Electronic Shelf Labels

May 4, 2026 by 70 Comments

Was there ever anything wrong with simple paper price labels? Absolutely not. And yet, the world invented the electronic price tag anyway. If you happen to come across some of these devices and want to hack them, you might like TagTinker from [i12bp8].

TagTinker is a Flipper Zero application specifically built for talking to infrared electronic shelf labels (ESLs). These are e-paper devices that receive commands and updates via an infrared interface, and they’re relatively simple to talk to. [i12bp8] built upon previous work from [furrtek] which revealed the protocols used to update these devices, and implemented it into an app that runs on the Flipper. It can do neat things like scan the NFC tags built into ESLs to ID them, deploy bitmap images to the tags, or run live-updated dashboards on the devices with the aid of a Flipper WiFi devboard.

If you’ve always wanted to play with these tags but didn’t want to do the grunt work yourself, it just got a whole lot easier to mess around. Though, it’s worth noting, [i12bp8] has strictly prohibited any illegal uses of this app, so be good out there. We’ve seen these tags repurposed before, too – who knew they could make such good conference badges? 

TDR For Auto Diagnostics Done On The Cheap

May 4, 2026 by 14 Comments

A time domain reflectometer (TDR) is a useful tool to have for finding faults in a wiring harness. However, they don’t come cheap, putting them out of reach for many shadetree mechanics that like to work on their own cars. However, [László SZŐKE] has been exploring a neat way to build a similar device on the cheap.

Typically, time domain reflectometry involves shooting a short electric pulse down a wire, and listening for how long it takes to bounce back. The time depends on the length of the wire, so it can be used to determine the location of a break in conductivity. Unfortunately, these pulses move so fast that very fast, very expensive hardware is needed to make these measurements.

[László’s] technique relies on lower-tech hardware. Instead of sending a very short pulse down a wire, his rig uses a cheap C-Media USB audio device to send a 4 kHz or 8 kHz sine wave instead. Then, by listening to the reflection and measuring the phase shift, it’s possible to detect the distance to the end of the wire (or a break along its length). Some supporting hardware is required for protection’s sake, and to tune the setup for measuring shorter or longer cabling. However, with some smart software processing, [László] states that it’s possible to measure down to 1 cm resolution.

The idea is that this setup could prove particularly useful for automotive troubleshooting. If you measure a wire and the device reports a length of 30 cm, when you know the wire stretches several meters into the engine bay… you know there’s a break around 30 cm from your measurement point.

There’s still plenty of work to be done – for now, [László] is working on a new prototype that should have better performance when testing shorter cables. Still, we love to see this sort of out-of-the-box thinking put towards a common troubleshooting task. If you’re doing fun signal analysis work of your own, don’t hesitate to light up the tipsline.

IPod Nano Gets Three Monitors

May 3, 2026 by 8 Comments

Triple monitor workstations are pretty common these days, particularly for those wishing to maximise screen space for greater productivity. [Will It Work?] has put together a sillier take on this concept, however, hooking the diminutive iPod Nano up to three monitors instead.

The 6th-generation iPod nano brought forth a new form factor – it’s the postage stamp-sized one that you could clip to your workout gear. It’s not typically what you’d call a productivity device, but there is a way to get more out of it. The trick is to grab a 30-pin Keyboard Dock, which allows access to the composite video signal from the iPod. It was originally designed for the iPad, but it works with the iPad nano too with a 30-pin spacer adapter – just don’t expect the keys to do anything. This setup also allows access to the 3.5mm four-pole jack, which handles audio input and output. With a bunch of additional cables and adapters, the iPod was able to be hooked up to three screens, a set of Apple Pro speakers, and three Sharp LCD monitors.

What can you do with this setup? Fundamentally, not a whole lot. You can’t use the keyboard with the iPod Nano, so you’re limited to interacting with the tiny touchscreen. There also aren’t exactly a lot of apps to run on the platform, either. You can basically listen to music, watch a slide show, or record voice memos, while looking at the iPod’s display spread identically across three TVs. Still, it’s a fun joke build, because at a glance it genuinely looks like you’ve set up a triple-monitor workstation running off a tiny iPod from over a decade ago.

If you want to blow the mind of your next podcast guest, consider recording your next episode on this rig. Alternatively, explore some of the other hacks we’ve seen for the platform. Video after the break.

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