Testing Giant Fire Darts From The Mary Rose

Fire arrow versus the recreated fire dart. (Credit: Tod's Workshop, YouTube)
Fire arrow versus the recreated fire dart. (Credit: Tod’s Workshop, YouTube)

The Mary Rose was a carrack in the English Tudor Navy of King Henry VIII  that fought in multiple battles during the 16th century before it was sunk in 1545. After its wreck was located in 1971 and raised in 1982 the ship and all the items contained within the partially preserved hull became the focus of intense study. Among these items are the weaponry found, including the cannons, but also massive darts that seemed to have been designed for an incendiary payload. Recently [Tod’s Workshop] collaborated with others to test these presumed incendiary darts.

Although fire arrows have been around for a while, seeing what appears to be super-sized versions of these is somewhat unusual, but could make sense in taking out enemy ships of the time. The main questions are how you would even fire them, and how effective they would be. Were the darts thrown by hand from e.g. the crow’s nest, or fired from a cannon?

The reproduction darts used are based on the recovered remnants of the original darts, with an incendiary mixture inside a pitch-covered cloth covering. This mixture would be ignited by wooden fuses after a set amount of time, at which point the resulting fire would be basically impossible to put out. Obviously, this also means that if you were to throw one of these darts, it can absolutely not fall onto your own ship.

First tested was throwing the dart by hand, which seems like it would clear the ship. Of course, the three recovered darts were found near a rather special cannon that appeared to be both a miscast and angled upwards. Whether that cannon was used for launching apparently somewhat experimental darts is hard to say, but it can be tested. Sadly, lacking a full-sized black powder cannon a scale model dart was fired using compressed air.

From that scale test it’s clear that at full charge the dart would disintegrate due to the rapid acceleration, but a ‘soft’, or reduced, charge could work against nearby targets. Once the dart lodges itself into the enemy ship’s structure, it would definitely cause severe damage as further tests in the video demonstrate. Having a salvo of these fire darts fired at you from a nearby ship would definitely make for a pretty bad day.

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Y-zipper: 3D Printing Flexible–Rigid Transition Mechanism For Rapid And Reversible Assembly

Along with Velcro, zippers have become an integral part of every day life, being a quick and easy way to usually temporarily join fabric together. Which isn’t to say that you cannot do more with the basic zipper concept, including using them to turn floppy 2D shapes into rigid 3D ones, such as with the Y-zipper concept proposed and demonstrated by [Jiaji Li] et al.

Although not a fully new idea, the Y-zipper is compared with a range of similar mechanisms that do not feature the same abilities, including the standard zipper ease of zipping up, the possibility of having curved geometry and automatic actuation.

Plus there is that the Y-zipper is designed from the start to be 3Dprinted, while still following the same basic pattern of interlocking teeth that the slider mechanism alternately pushes together or pulls apart.

By modifying the basic straight design of the flat strips, the resulting zipped-up form can take on a distinct bend, as well as turn into a coil or a screw. With a demonstrated joint design it is then possible to join multiple Y-zipper rods together, which could make for an interesting alternative to traditional pop-up tent supports, for example.

Also demonstrated is the use of TPU to create compliant bridges, as well as the direct integration of fabric, to show the versatility of the technology. With the used materials (PLA, TPU) the researchers estimate a maximum viable length of about 3 meters before the printed structures begin to disintegrate.

The Dark Side Of Unitree Robot Dogs

Arbitrary command execution with the Wi-Fi password. (Credit: Benn Jordan)
Arbitrary command execution with the Wi-Fi password. (Credit: Benn Jordan)

Continuing on his quest to expose the dark underbelly of modern technology, [Benn Jordan] recently did a deep-dive into the rise of so-called robot dogs. Although their most striking resemblance with biological dogs is that they also have four legs and generally follow commands, [Benn] found many issues with them that range from safety issues due to limited sensory capabilities, to basic security vulnerabilities, all the way to suspicious network traffic from Unitree’s robot dog firmware.

Although not the only seller of this type of quadruped robot, Unitree Robotics has made a name for itself by offering very capable and yet very cheap products. Their basic quadruped robot costs only a few thousand clams and features Lidar and heaps of processing power, all of which should make it a pretty useful device.

Despite this, [Benn] found that the original task that he’d envisioned for the robot, as in protecting his chickens from uninvited visitors, wouldn’t quite work as the robot is rather blind. The reason for this is the placement of the Lidar below the head, which obscures most of what’s behind and around the robot. Rather than risk trampled chickens and chicks, this plan was thus abandoned.

When digging further into the robot, he found an easy to exploit arbitrary command execution flaw via the Wi-Fi password entry field, a year-old CVE-2025-2894 exploit, as well as highly suspicious traffic to Chinese servers whenever the robot’s software figured that it was not being watched.

Although much of this can be circumvented with hacks, issues like the sensory limitations and general distrust of firmware updates makes using these robots a rather daunting and often ill-advised proposition.

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Trying To Fix A GoPro Hero 10 With A No Camera Input Issue

In the search for more exciting broken electronics to repair, [Hugh Jeffreys] bought a GoPro Hero 10 for US$100 with an apparently rather common issue of no camera input, along with a cracked display. This particular camera issue is rather obvious, with just darkness where the camera’s input should appear on the display. Since [Hugh] already needed a spare display, he figured that he might as well get an even more broken GoPro Hero 10 for parts.

Another US$40 later, [Hugh] found himself the proud owner of a second GoPro, this one being water damaged and no longer turning on. Getting to the internals requires removing the glued-in display, which is even trickier than with a smartphone. By inserting a thin blade, adding solvents and not prying, you can slowly work it loose.

With two disassembled GoPros it was now possible to swap modules. After a factory reset and firmware update had failed to fix the first GoPro, the camera module from the donor unit was inserted, but this made no difference. Amusingly, after cleaning the water-damaged unit’s PCBs, it was found to be in good working condition, so ultimately the second GoPro was repaired, leaving the ‘no camera input’ issue undiagnosed.

It’s possible that a board-level repair on the first unit can address the original issue, but without schematics this would likely entail a lot of blindly poking around, in the hope of finding a damaged MLCC or other obvious fault. There is also the possibility that this is a firmware issue, with some reporting luck mashing the record button, but others disagree.

Since [Hugh] did do the firmware reset and updating steps, and even inserted a whole new working camera module, it would seem to narrow the problem down to a board-level issue. Whatever the case may be, it’s a frustrating issue with a rather expensive device.

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Reverse-Engineering And Documenting The Fisher Price Pixter

Between 2000 and 2002 the Fisher Price Pixter was sold to children as an educational handheld toy with a touch screen that enabled drawing and listening to music in addition to cartridge-based games and more. It was followed up by multiple new iterations of the system, but as an ecosystem didn’t last beyond 2007. This has left much of the system in obscurity, with people like [Dmitry] doing their best to reverse-engineer, dump and document what they can, such as recently for the entire range of Pixter devices and most of the games.

One of the reasons why [Dmitri] got interested in the second-generation Pixter Color originally was as a potential PalmOS porting target, which gives somewhat of an idea of how these devices were meant to be used.

With absolutely no remaining known official documentation on how to develop software for the hardware reverse-engineering posed somewhat of a challenge. Fortunately this was made somewhat easier by the Pixter Color using the ARM-based LH7541, but worse by just how much of a minimal ARM7 implementation the SoC is. This was meant to go into a cheap-ish kid’s toy after all.

Where things got wild was that the firmware implements a 16-bit stack-based virtual machine, possibly due to initially having selected a completely different SoC. From here things get even crazier with how audio output is implemented, with [Dmitry] descending into a long-winded rant on this and all the weird things encountered during reverse-engineering.

After the Color Pixter its Multimedia sibling with slightly better SoC was also reverse-engineered, as well as the Classic device that started it all. This particular device uses an 8-bit VM, but a black-blob 6502 processor, which is rather astounding for a 2000-era device, but then again it was meant to be a toy.

In addition to getting a lot of reverse-engineering woes off his chest, [Dmitri] also details how he reverse-engineered and dumped the cartridges, as well as writing emulators to ensure that the Pixter legacy will endure, for better or worse.

Top image: Pixter with opened case. (Credit: Raimond Spekking, Wikimedia)

Making Big Dry Ice Blocks With Low Pressure CO2

Although the term ‘dry ice’ is generally used for solid CO2, it’s much more accurate to call this ‘dry snow’, as, rather than being actual solid blocks, they are effectively snow that’s been compressed really tightly. While not really necessary for most applications of dry ice, it is possible to make blocks of actual CO2 ice, and thus [Hyperspace Pirate], as someone with a healthy obsession with cold things had to make some of his own.

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Why Using Cardboard For A PC Case Is A Chore

The idea of using cardboard for a sloppy PC case isn’t new; it’s a time-honored tradition dating back to at least the 1990s. That said, with today’s CNC cutters and other advanced tooling available to hobbyists, you might be curious to see how far you can push the concept. As demonstrated in a recent video by [mryeester], the answer appears to be that good planning and a solid understanding of cardboard’s limitations are as essential as ever.

After having the PC case drawn up in CAD and cut on a professional CNC cutter by a buddy who makes commercial cardboard displays, the installation procedure for the PC components showed where a bit of foresight could have saved a lot of time and effort.

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