Dissecting A Lethal Universal Travel Adapter

August 30, 2026 by No comments

The world’s refusal to standardize on a single type of mains power outlet has led to a vibrant market of so-called travel adapters, all of which try to outdo each other in convenience and universality. This comes at the cost of complexity, something which ultimately reflects in the price. The cheapo $9.26 universal travel adapter that [Brainiac 75] got off an online retailer’s site is thereby a good example of how safety suffers if the overarching goal is to ‘make it cheap’.

The first exciting discovery is that when you plug any of its three sets of connectors into an outlet, the others become live at the same voltage. This would suggest that they’re just wired together, a fact soon confirmed with a quick resistance check between the respective prongs. Though to the adapter’s credit, the prongs are not live when fully retracted into the enclosure. Yet as demonstrated in the video, the retracting of prongs is not enforced, so mistakes here are possible.

The adapter also has two USB ports that claim to provide 5 V at 2.1 A, with as it turns out no hard cut-off. This is probably the best part of the adapter despite not featuring any advanced charging features. After opening the adapter, you can see that the sliding mains prongs connect to a central bus bar when either unfolded or extended, which is definitely straightforward, but doesn’t enforce that only one type of prongs can be used at any given time.

To make it safer, [Brainiac75] removed the less useful US and UK plugs, taping over the empty holes. It’s now just a USB charger with a universal mains port to plug random non-EU plugs into, which is probably relatively safe and a better idea than really using it as a travel adapter.

Continue reading “Dissecting A Lethal Universal Travel Adapter” →

LLM Moats Quickly Evaporating

August 30, 2026 by 15 Comments

In the business world, a moat is a quality of a business that makes it difficult for competitors to take that company’s profits. With how hard it is to train models for large language models (LLMs) and generative AI, it might seem like Anthropic, Open AI, and other LLM companies would have huge moats given the amount of compute it takes to build models. But open source models are quickly draining that moat, and now the only thing standing in the way of a customer using one of these models on their own hardware instead one from the larger companies is physical computing resources. [TerminalBytes] demonstrates a few of these models on personally owned computers to show the current state of the art.

[TerminalBytes] started off running the 27B version of the Qwen3.8 on a Mac Studio with 256 GB of unified RAM, which is plenty for this task. But it’s also enough to benchmark a few different models. Qwen3.6 is compared to 3.8, and then the different quants of each model are also compared. Quants are compressed versions of models that need fewer bits to store weights, meaning that the same models can run in less memory with smaller losses in fidelity. Many of these quants run on machines with 32 GB of RAM or less, encompassing many average gaming PCs. There’s even a 1-bit quant that [TerminalBytes] tested which can easily run on a machine with 16 GB, although with mixed results.

Keep in mind that this is just the current state of affairs with open LLMs. Future versions of these models are likely to optimize the number of tokens produced per unit time, or otherwise increase quality of responses while requiring less computer resources. We don’t really think that the ease of running local models will be the sole reason that the AI bubble pops, though. The fact that not every computer user is running Linux is proof enough of that.

Low(er)-Cost Humanoid Robot Leverages DIY Actuators

August 30, 2026 by 2 Comments

Humanoid robots, even scaled-down ones, tend to be expensive. The Berkeley Humanoid Lite offers a more accessible and economical option by centering the design around 3D printed actuators that make up the bulk of the robot’s frame.

The actuators are made by combining motors with printed cycloidal gearboxes and an embedded magnetic encoder. They’re modular, so even if one has no desire to recreate the whole robot it might be worth checking out the actuator design details to see if they might be useful in some other way.

The Berkeley Humanoid Lite isn’t a finished product so much as an open-source, easily customized reference design. The GitHub repository contains everything one might need, and you can watch some basic demonstrations, including VR-driven teleoperation, in the video embedded below.

At a total hardware cost of under $5,000 USD it’s still expensive, but much more economical than other humanoid robots, open-source or not. As mentioned, even if one doesn’t plan to build one, the modular actuator design is worth keeping in mind for other purposes.
Continue reading “Low(er)-Cost Humanoid Robot Leverages DIY Actuators” →

Giving The NES An Optical Data Storage Add-On

August 30, 2026 by No comments

The introduction of optical media in the form of CDs meant a revolution in the world of gaming consoles, escaping the restrictions of a few dozen MB of storage and instead offering a theoretically infinite amount of storage through the miracle and tedium of swapping discs. After the SNES narrowly escaped getting a CD add-on and the N64 doubled down on cartridges, we can now at least get an impression of what it’d be like if the Nintendo Entertainment System had been gifted a CD add-on back in the 1980s, courtesy of a project by [Throaty Mumbo].

The NES future we could have had. (Credit: Throaty Mumbo, YouTube)
The NES future we could have had.

There’s also an accompanying video containing typical hijinks and a demonstration of this system. Initially [Throaty Mumbo] was going to make a SNES CD add-on to match that console’s initial prototype, but doing it for the NES seemed more fun. Obviously, since the NES is quite limited hardware-wise it was always going to be a struggle, even if the original front-loading NES conveniently has a mostly unused expansion slot.

On the custom PCB there is an RP2350B microcontroller that mediates between an Everdrive N8 Pro cartridge and an IDE CD drive, along with a PCM5102 audio DAC. The expansion port is hereby used to receive the audio samples on its audio mix input pin, along with power. After boot the game ROM is read off the CD by the MCU and streamed over USB to the Everdrive.

Combined with the previous work [Throaty Mumbo] did to revive the long-defunct Japanese online service for the NES, it’s an exciting time for fans of the iconic console.

Continue reading “Giving The NES An Optical Data Storage Add-On” →

Woodstove Assistant Keeps The Heat On Safely

August 30, 2026 by No comments

Those who have never lived in a cold climate might romanticize winters around a fire, keeping warm under blankets while snow gently falls outside. While it certainly can be a cozy experience, using a woodstove comes with a number of pitfalls, and when operated improperly can even cause house-destroying chimney fires. Modern stoves operated properly with properly dried wood make this possibility extremely remote, but it’s still worth keeping an eye on. Reddit user [nas886] built a system called Oru which takes a lot of the guesswork out using one of these pieces of heating equipment.

The real danger of a woodstove isn’t necessarily running the fire too hot, although that can be a problem, but running it too cold. Without full combustion of the wood, flammable creosote builds up on the inside of the chimney which eventually can combust. This system uses a probe placed in the stovepipe to monitor the temperature of the exhaust gasses. If it’s too low an ESP32 notifies [nas886] remotely with with a status LED inside a seperate custom-built walnut enclosure so that more wood can quickly be added or airflow increased to bring up the temperature, and in the case that the fire gets too hot the LED changes to a different color and the air can be closed off a bit.

Woodstoves themselves have quite a bit of variability in the size wood they can burn, the amount they can hold at once, their efficiency, and their thermal mass, so this could find utility for anyone from those with tiny stoves that have to be fed constantly to those trying to get all-night burns in massive units, all without having to constantly sit by the fire and monitor it. [nas886] found initial success selling a few of these custom units and plans to put it into further production as well, but the general idea is not too difficult to replicate for most of us here either.

Continue reading “Woodstove Assistant Keeps The Heat On Safely” →

Laser Your Way To Smoother FDM 3D Prints

August 29, 2026 by 13 Comments

Now, not everyone minds the characteristic layer lines you get with Filament Deposition Modeling (FDM) 3D prints, but sometimes you need a smooth surface. If so we might go for filling primer, Bondo, or maybe break out the ABS and vapor smooth. Well, [I changed a thing] has an alternate suggestion: lasers. Laser melting can smooth the walls on a print, or the top surfaces as he shows in two different videos, both embedded below. The results look roughly similar to vapor smoothing, without the chemical exposure small risk of explosion.

Of course, you need a laser to do this, and [I changed a thing] has two diode lasers mounted to the X-axis of his printer. Of the two, the top surfaces were a lot easier to get right than the wall smoothing, which makes sense. Top surfaces are right there for the laser to get at, after all, while with his laser setup [I changed a thing] needs to get at the walls obliquely. [I changed a thing] tries melting layer-by-layer as well as a few methods to get at the walls of a finished print; which works best seems to depend on the size of and geometry of the object, so it looks like this technique is as much art as science right now.

This effort is closely related to the previous work [I changed a thing] did on improving layer adhesion with laser melting.  It’s also not the first time we’ve seen laser-driven print smoothing, but that project used non-planar movements to do a post-print laser pass.

Continue reading “Laser Your Way To Smoother FDM 3D Prints” →

Fat Tire Brakes Get Wireless Upgrade

August 29, 2026 by 39 Comments

At first glance, wireless brakes seem like a recipe for disaster. For something as critical as braking, many bicyclists might prefer a physical connection to their method of safely controlling speed. But there are a number of surprising benefits of electronic or wireless braking systems. For one, they can enable systems like anti-lock braking systems and for another they can eliminate cabling or hydraulics on a bicycle. For these reasons, and just for the thrill of it, [Berm Peak] built a set of wireless brakes for his fat tire bicycle to test out the possibilities.

The system uses a set of ESP32 microcontrollers to handle inputs from the braking lever and outputs to the front and rear brakes, as well as a central control unit and display. The brakes themselves are controlled by actuators from car door locks, which when combined with the springs from the stock calipers work to apply a wide range of braking force to the wheels. These did take a bit of prototyping to get working right, by changing to higher quality calipers, increasing the angle of the actuator, and adding longer levers, but eventually a working braking system started to appear.

But replacing a hydraulic system with an electronic one isn’t where something like this shines. [Berm Peak] was able to add in a number of features impossible in traditional braking systems. Not only does this have an ABS system and the possibility to remotely slow down his children’s bikes when they’re riding, but there’s also a braking equalizer that allows the rider to control how much braking there is at certain positions of the brake lever, and another setting called “derp” which doesn’t engage the brakes at all until a certain threshold has passed. This might end up being the next big trend in mountain biking, unlike airless tires.

Continue reading “Fat Tire Brakes Get Wireless Upgrade” →