Should You Try Printing With Polypropylene?

August 18, 2025 by 11 Comments

Of all the plastics that surround us on the daily, the one we hear least about in the 3D printing world is probably polypropylene (PP). Given that this tough, slightly flexible thermoplastic has characteristics you might want for your prints, the question is: why? [Lost in Tech] is not answering that question in a recent video; instead he’s showing us what we’re missing out on with a review of the material.

A look at the Material Safety Data Sheet and available material has [Lost in Tech] suggesting it won’t be (much) more toxic for you than PLA, but you still wouldn’t want to huff the fumes. The biggest issue printing PP is getting it to stick — glass beds and PEI are not your friend, but polypropylene tape is easy to find and makes a fine print surface. He reviews a few other options, but it looks like plain old tape is still your best bet if you can’t get a hold of a Prusa PP bed. The other big issue is shrinkage, but that’s hardly unique to PP and can be accounted for in the model.

Just because it can be used, that doesn’t mean it should be. [Lost in Tech] does make a good case for why you might want to use PP — for one thing, it doesn’t string much, in part because it’s not hygroscopic. That makes it great for those of us in humid climes who don’t want to always faff around with dry boxes, but also wonderful for parts that will be in touch with water. Polypropylene also has great chemical resistance for even scarier chemicals than dihydrogen monoxide. The “killer app” though, at least as far as [Lost in Tech] is concerned, is to use polypropylene with compliant mechanisms: it’s incredibly resilient to bending, and doesn’t fatigue easily. You might even call it a “flexible” filament, but unlike with TPU, you get a nice hard plastic to go with that flexibility.

If you’re interested in this somewhat-forgotten filament, we featured a “getting started” guide last year. You can even make your own polypropylene filament using non-medical “COVID” masks, but do be sure to wash them first. What do you think? Is it time to give PP another chance, or has the 3D printing world moved on? Continue reading “Should You Try Printing With Polypropylene?” →

The Terminal Demise Of Consumer Electronics Through Subscription Services

August 18, 2025 by 86 Comments

Open any consumer electronics catalog from around the 1980s to the early 2000s and you are overwhelmed by a smörgåsbord of devices, covering any audio-visual and similar entertainment and hobby needs one might have. Depending on the era you can find the camcorders, point-and-shoot film and digital cameras right next to portable music players, cellphones, HiFi sets and tower components, televisions and devices like DVD players and VCRs, all of them in a dizzying amount of brands, shapes and colors that are sure to fit anyone’s needs, desires and budget.

When by the late 2000s cellphones began to absorb more and more of the features of these devices alongside much improved cellular Internet access, these newly minted ‘smartphones’ were hailed as a technological revolution that combined so many consumer electronics into a single device. Unlike the relatively niche feature phones, smartphones absolutely took off.

Fast-forward more than a decade and the same catalogs now feature black rectangles identified respectively as smart phones, smart TVs and tablets, alongside evenly colored geometric shapes that identify as smart speakers and other devices. While previously the onus for this change was laid by this author primarily on the death of industrial design, the elephant in the room would seem to be that consumer electronics are suffering from a terminal disease: subscription services.

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Sniffing 5G With Software-Defined Radio

August 18, 2025 by 3 Comments

The fifth generation mobile communications protocol (5G) is perhaps the most complicated wireless protocol ever made. Featuring wildly fast download speeds, beam forming base stations, and of course non-standard additions, it’s rather daunting prospect to analyze for the home hacker and researcher alike. But this didn’t stop the ASSET Research Group from developing a 5G sniffer and downlink injector.

The crux of the project is focused around real-time sniffing using one of two Universal Software Radio Peripheral (USRP) software-defined radios (SDRs), and a substantial quantity of compute power. This sniffed data can even be piped into Wireshark for filtering. The frequency is hard-coded into the sniffer for improved performance with the n78 and n41 bands having been tested as of writing. While we expect most of you don’t have the supported USRP hardware, they provided a sample capture file for anyone to analyze.

The other main feature of the project is an exploitation framework with numerous attack vectors developed by ASSET and others. By turning an SDR into a malicious 5G base station, numerous vulnerabilities and “features” can be exploited to with results ranging from downgrading the connection to 4G, fingerprinting and much more. It even includes an attack method we preciously covered called 5Ghull which can cause device failure requiring removal of the SIM Card. These vulnerabilities offer a unique look inside the inner workings of 5G.

If you too are interested in 5G sniffing but don’t have access to the hardware needed, check out this hack turning a Qualcomm phone into a 5G sniffer!

A fisheye lens picture over the Junma Solar Power station in the Mongolian desert. There is a large image of a horse made out of solar panels in the image. A sunset is visible in the upper right of the image, but most the picture is brown sand where there aren't dark blue solar panels.

China’s Great Solar Wall Is A Big Deal

August 18, 2025 by 60 Comments

Data centers and the electrification of devices that previously ran on fossil fuels is driving increased demand for electricity around the world. China is addressing this with a megaproject that is a new spin on their most famous piece of infrastructure.

At 250 miles long and 3 miles wide with a generating capacity of 100 GW, the Great Solar Wall will be able to provide enough energy to power Beijing, although the energy will more likely be used to power industrial operations also present in the Kubuqi Desert. NASA states, “The Kubuqi’s sunny weather, flat terrain, and proximity to industrial centers make it a desirable location for solar power generation.” As an added bonus, previous solar installations in China have shown that they can help combat further desertification by locking dunes in place and providing shade for plants to grow.

Engineers must be having fun with the project as they also designed the Guinness World Record holder for the largest image made of solar panels with the Junma Solar Power Station (it’s the horse in the image above). The Great Solar Wall is expected to be completed by 2030 with 5.4 GW already installed in 2024.

Want to try solar yourself on a slightly smaller scale? How about this solar thermal array inspired by the James Webb Telescope or building a solar-powered plane?

Cracking Abandonware DRM Like It’s 1999

August 17, 2025 by 11 Comments

As long as there have been games, there have been crackers breaking their copy protections. “Digital Rights Management” or DRM, is a phrase for copy protection coined near the end of the 1990s, and subverted shortly thereafter. But how? [Nathan Baggs] show us what it took to be a cracker in the year 2000, as the first step to get an old game going again turned out to be cracking it. 

The game in question is “Michelin Rally Masters: Race of Champions” by DICE, a studio that was later subsumed by EA and is today best known as the developers of the Battlefield franchise. The game as acquired from an abandonware site does not run in a virtual machine, and after a little de-obfuscation of the code causing the crash, [Nathan] discovers LaserLock is to blame. LaserLock was a DRM tool to lock down a game to its original CD-ROM that dates all the way back to 1995. Counters to LaserLock were probably well-known in the community back in the day, but in 2025, [Nathan] walks us through attempting to crack it it from first principles.

We won’t spoil the whole assembly-poking adventure, but the journey does involve unboxing an original CD to be able to compare what’s happening when the disc is physically present compared to running from the ISO. Its tedious work and can only be partially automated. Because it did prove so involved, [Nathan]’s original aim — getting the game to work in Windows 11 — remains unfulfilled so far.

Perhaps he’d have had better luck if he’d been listening to the appropriate music. Frustrating DRM isn’t always this hard; sometimes all you needed was a paperclip. Continue reading “Cracking Abandonware DRM Like It’s 1999” →

Practical Guide To Pedal-Powered Electrical Generators

August 17, 2025 by 51 Comments

An adult human can produce about 100 Wh of mechanical power whilst cycling, which is a not inconsiderable amount if you can convert that to electricity with reasonable efficiency. In a recent article on EDN [T. K. Hareendran] goes over a few ways that you can turn the rotary motion of pedaling into usable electrical power.

Suggested voltage regulator for pedal-powered generator. (Credit: T. K. Hareendran, EDN)
Suggested voltage regulator for pedal-powered generator. (Credit: T. K. Hareendran, EDN)

A basic form of this is already widely deployed, in the form of a bicycle dynamo that is used to supply power to the front and rear lights. These typically put out something like 3 watts at 6 VAC, so with a simple bridge rectifier and some smoothing this can power a pretty bright LED or two. To get more out of it, you need to use a more capable generator, which can also be a brushed or brushless DC motor in a pinch, with ideally a flywheel in the whole contraption to balance out variations in the human power input.

As for the potential here, a commercial solution like the K-Tor Power Box 50 is specified for ‘greater than’ 50 Watt, with a nominal 12 VDC output. Its target market is emergency generators, with enough capability to keep phones, radios and flashlights charged. Considering the $435 asking price, there is probably quite a lot of DIY potential well within that price bracket, especially if you already have many of the requisite parts lying around.

Fortunately this is not a new idea, with us having covered using bicycles as well as gym equipment to generate electricity in the past.

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Hackaday Links: August 17, 2025

August 17, 2025 by 15 Comments

We’ve studiously avoided any mention of our latest interstellar visitor, 3I/Atlas, on these pages, mainly because of all the hoopla in the popular press about how Avi Loeb thinks it’s aliens, because of course he does. And we’re not saying it’s aliens either, mainly because we’d never be lucky enough to be alive during an actual alien invasion — life just hasn’t historically been that kind to us. So chances are overwhelming that 3I/Atlas is just a comet, but man, it’s doing its level best to look like it’s not, which means it’s time to brave the slings and arrows and wade into this subject.

The number of oddities surrounding 3I/Atlas just keeps growing, from its weird Sun-directed particle stream to its extreme speed, not to mention a trajectory through the solar system that puts it just a fraction of an astronomical unit from two of the three planets within the “Goldilocks Zone” of our star — ignore the fact that at an estimated seven billion years old, 3I/Atlas likely would have started its interstellar journey well before our solar system had even started forming. Still, it’s the trajectory that intrigues us, especially the fact that it’s coming in at a very shallow along to the ecliptic, and seems like it will cross that imaginary plane almost exactly when it makes its closest approach to the Sun on October 29, which just coincidentally happens to be at the very moment Earth is exactly on the opposite side of our star. We’ll be as far as possible from the action on that date, with the comet conveniently lost in the glare of the Sun. Yes, there’s talk of re-tasking some of our spacecraft around Mars or in the Jovian system to take a peek when 3I/Atlas passes through their neighborhoods, but those are complicated affairs that show no sign of bearing fruit in the short time left before the comet heads back out into the Deep Dark. Too bad; we’d really love an up-close and personal look at this thing.

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