Conservation of energy isn’t just a good idea: It is the law. In particular, it is the first law of thermodynamics. But, apparently, a lot of people don’t really get that because history is replete with inventions that purport to run forever or produce more energy than they consume. Sometimes these are hoaxes, and sometimes they are frauds. We expect sometimes they are also simple misunderstandings.

We thought about this when we ran across the viral photo of an EV with a generator connected to the back wheel. Of course, EVs and hybrids do try to reclaim power through regenerative braking, but that’s recovering a fraction of the energy already spent. You can never pull more power out than you put in, and, in fact, you’ll pull out substantially less.

Not a New Problem

If you think this is a scourge of social media and modern vehicles, you’d be wrong. Leonardo da Vinci, back in 1494, said:

Oh ye seekers after perpetual motion, how many vain chimeras have you pursued? Go and take your place with the alchemists.

There was a rumor in the 8th century that someone built a “magic wheel,” but this appears to be little more than a myth. An Indian mathematician also claimed to have a wheel that would run forever, but there’s little proof of that, either. It was probably an overbalanced wheel where the wheel spins due to weight and gravity with enough force to keep the wheel spinning.

An architect named Villard de Honnecourt drew an impractical perpetual motion machine in the 13th century that was also an overbalanced wheel. His device, and other similar ones, would require a complete lack of friction to work. Even Leonardo da Vinci, who did not think such a device was possible, did some sketches of overbalanced wheels, hoping to find a solution.

Types of Machines

There isn’t just a single kind of perpetual motion machine. A type I machine claims to produce work without any input energy. For example, a wheel that spins for no reason would be a type I machine.

Type II machines violate the second law of thermodynamics. For example, the “zeromoter” — developed in the 1800s by John Gamgee, used ammonia and a piston to move by boiling and cooling ammonia. While the machine was, of course, debunked, Gamgee has the honor of being the inventor of the world’s first mechanically frozen ice rink in 1844.

Type III machines claim to use some means to reduce friction to zero to allow a machine to work that would otherwise run down. For example, you can make a flywheel with very low friction bearings, and with no load, it may spin for years. However, it will still spin down.

Often, machines that claim to be perpetual either don’t really last forever — like the flywheel — or they actually draw power from an unintended source. For example, in 1760, James Cox and John Joseph Merlin developed Cox’s timepiece and claimed it ran perpetually. However, it actually drew power from changes in barometric pressure.

Frauds

These inventions were often mere frauds. E.P. Willis in 1870 made money from his machine but it actually had a hidden source of power. So did John Ernst Worrell Keely’s induction resonance motion motor that actually used hidden air pressure tubes to power itself. Harry Perrigo, an MIT graduate, also demonstrated a perpetual motion machine to the US Congress in 1917. That device had a secret battery.

However, some inventors probably weren’t frauds. Nikola Tesla was certainly a smart guy. He claimed to have found a principle that would allow for the construction of a Type II perpetual motion machine. However, he never built it.

There have been hosts of others, and it isn’t always clear who really thought they had a good idea and how many were just out to make a buck. But some people have created machines as a joke. Dave Jones, in 1981, created a bicycle wheel in a clear container that never stopped spinning. But he always said it was a fake and that he had built it as a joke. Adam Savage looks at that machine in the video below. He wrote his secret in a sealed envelope before he died, and supposedly, only two people know how it works.

Methods

Most perpetual machines try to use force from magnets. Gravity is also a popular agent of action. Other machines depend on buoyancy (like the one in the video below) or gas expansion and condensation.

The US Patent and Trademark Office manual of patent examining practice says:

With the exception of cases involving perpetual motion, a model is not ordinarily required by the Office to demonstrate the operability of a device. If operability of a device is questioned, the applicant must establish it to the satisfaction of the examiner, but he or she may choose his or her own way of so doing.

The UK Patent Office also forbids perpetual motion machine patents. The European Patent Classification system has classes for “alleged perpetua mobilia”

Of course, having a patent doesn’t mean something works; it just means the patent office thought it was original and can’t figure out why it wouldn’t work. Consider Tom Bearden’s motionless electromagnetic generator, which claims to generate power without any external input. Despite widespread denouncement of the supposed operating principle — Bearden claimed the device extracted vacuum energy — the patent office issued a patent in 2002.

The Most Insidious

The best machines are ones that use energy from some source that isn’t apparent. For example, a Crookes radiometer looks like a lightbulb with a little propeller inside. Light makes it move. It is also a common method to use magnetic fields to move something without obviously spinning it. For example, the egg of Columbus (see the video below) is a magnet, and a moving magnetic field makes the egg spin. This isn’t dissimilar from a sealed pump where a magnet turns on the dry side and moves the impeller, which is totally immersed in liquid.

Some low-friction systems, like the flywheel, can seem to be perpetual motion machines if you aren’t patient enough. But eventually, they all wear down.

Crazy or Conspiracy?

Venues like YouTube are full of people claiming to have free energy devices that also claim to be suppressed by “the establishment”. While we hate to be on the wrong side of history if someone does pull it off, we are going to go out on a limb and say that there can’t be a true perpetual motion machine. Unless you cheat, of course.

This is the place we usually tell you to get hacking and come up with something cool. But, sadly, for this time we’ll entreat you to spend your time on something more productive, like a useless box or put Linux on your Commodore 64.

There’s a mystique in old keyboard circles around the IBM Model M, the granddaddy of PC keyboards with those famous buckling spring key switches. The original Model M was a substantial affair with a sheet metal backplane that would probably serve well as a weapon in a zombie apocalypse and still allow writing a Hackaday piece afterward, but later on in the life of these ‘boards there was also a lighter version. The M2 as these models are dubbed has a few known problems, and [Anders Nielsen] scored one online that turned out to have dodgy capacitors. His video, below the break, takes us through the disassembly of his M2 and provides a relaxing tour of these not-quite-so-famous peripherals.

As you’d expect, three-decade-old plastic isn’t always in the best shape, so disassembly and unlatching all those little tabs has to be performed with care. The keys come off and the springs are on show, but we get a nasty shock when they all fall out of place as the top is removed. It appears the rookie mistake is to not turn the ‘board upside down before parting it. Replacing the caps is an easy process after all that, and we get a little dive into the 6805 processors used in model Ms.

If you have a model M of any description then you’re probably at home with the clack-clack-clack sound they make, but have you ever looked at its ancestor, the model F?

In the communications surrounding LLMs and popular interfaces like ChatGPT the term ‘hallucination’ is often used to reference false statements made in the output of these models. This infers that there is some coherency and an attempt by the LLM to be both cognizant of the truth, while also suffering moments of (mild) insanity. The LLM thus effectively is treated like a young child or a person suffering from disorders like Alzheimer’s, giving it agency in the process. That this is utter nonsense and patently incorrect is the subject of a treatise by [Michael Townsen Hicks] and colleagues, as published in Ethics and Information Technology.

Much of the distinction lies in the difference between a lie and bullshit, as so eloquently described in [Harry G. Frankfurt]’s 1986 essay and 2005 book On Bullshit. Whereas a lie is intended to deceive and cover up the truth, bullshitting is done with no regard for, or connection with, the truth. The bullshitting is only intended to serve the immediate situation, reminiscent of the worst of sound bite culture.

When we consider the way that LLMs work, with the input query used to provide a probability fit across the weighted nodes that make up its vector space, we can see that the generated output is effectively that of an oversized word prediction algorithm. This precludes any possibility of intelligence and thus cognitive awareness of ‘truth’. Meaning that even if there is no intent behind the LLM, it’s still bullshitting, even if it’s the soft (unintentional) kind. When taking into account the agency and intentions of those who created the LLM, trained it, and created the interface (like ChatGPT), however, we enter into hard, intentional bullshit territory.

It is incidentally this same bullshitting that has led to LLMs being partially phased out already, with Retrieval Augmented Generation (RAG) turning a word prediction algorithm into more of a fancy search machine. Even venture capitalists can only take so much bullshit, after all.

A couple of weeks back we featured a story (third item) about a chunk of space jetsam that tried to peacefully return to Earth, only to find a Florida family’s roof rudely in the way. The 700-gram cylinder of Inconel was all that was left of a 2,360-kg battery pack that was tossed overboard from the ISS back in 2021, the rest presumably turning into air pollution just as NASA had planned. But the surviving bit was a “Golden BB” that managed to slam through the roof and do a fair amount of damage. At the time it happened, the Otero family was just looking for NASA to cover the cost of repairs, but now they’re looking for a little more consideration. A lawsuit filed by their attorney seeks $80,000 to cover the cost of repairs as well as compensation for the “stress and impact” of the event. This also seems to be about setting a precedent, since the Space Liability Convention, an agreement to which the USA is party, would require the space agency to cover damages if the debris had done damage in another country. The Oteros think the SLC should apply to US properties as well, and while we can see their point, we’d advise them not to hold their breath. We suppose something like this had to happen eventually, and somehow we’re not surprised to see “Florida Man” in the headlines.

There was a little hubbub this week around the release of a study regarding the safety of autonomous vehicles relative to their meat-piloted counterparts. The headlines for the articles covering this varied widely and hilariously, ranging from autonomous vehicles only being able to drive in straight lines to AVs being safer than human-driven cars, full-stop. As always, one has to read past the headlines to get an idea of what’s really going on, or perhaps even brave reading the primary literature. From our reading of the abstract, it seems like the story is more nuanced. According to an analysis of crashes involving 35,000 human-driven vehicles and 2,100 vehicles with some level of automation, AVs with SAE Level 4 automation suffered fewer accidents across the board than those without any automation. Importantly, the accidents that Level 4 vehicles do suffer are more likely to occur when the vehicle is turning just before the accident, or during low-visibility conditions such as dawn or dusk. The study also compares Level 4 automation to Level 2, which has driver assistance features like lane-keeping and adaptive cruise control, and found that Level 2 actually beats Level 4 in clear driving conditions, but loses in rainy conditions and pretty much every other driving situation.

There’s a strange story coming out of New York regarding a Federal Communications Commission (FCC) enforcement action that seems a little shady. It regards a General Mobile Radio Service (GMRS) repeater system used by the New York State GMRS Alliance. GMRS is sort of a “ham radio lite” system — there’s no testing required for a license, you just pay a fee — that uses the UHF band. Repeaters are allowed, but only under specific rules, and that appears to be where things have gone wrong for the club. The repeater system they used was a linked system, which connected geographically remote repeaters stretching from the far western part of the state near Buffalo all the way to Utica. It’s the linking that seems to have raised the FCC’s hackles, and understandably so because it seems to run counter to the GMRS rules in section 95. But it’s the method of notification that seems hinky here, as the repeater custodian was contacted by email. That’s not typical behavior for the FCC, who generally send enforcement notices by certified snail mail, or just dispense with the paper altogether and knock on your door. People seem to think this is all fake news, and it may well be, but then again, the email could just have been an informal heads-up preceding a formal notice. Either way, it’s bad news for the GMRS fans in upstate New York who used this system to keep in touch along Interstate 90, a long and lonely stretch of road that we know all too well.

Third time’s a charm? We’ll see when sunspot region AR3723 (née AR3697 née AR3664) makes a historic third pass around the Sun and potentially puts Earth in its crosshairs yet again. The region kicked up quite a ruckus on its first pass across the solar disk back in May with a series of X-class flares that produced stunning aurorae across almost all of North America. Pass number two saw the renamed region pass more or less quietly by, although it did launch an M-class flare on June 23 that caused radio blackouts in most of the North Atlantic basin. When AR3723 does peek out from behind the eastern limb of the Sun it’ll be a much-diminished version of its former Carrington-level glory, and will likely be given multiple designations thanks to fragmentation while it was hanging out on the backside. But it could still pack a punch, and even if this particular region doesn’t have much juice left, it sure seems like the Sun has plenty of surprises in store for the balance of Solar Cycle 25.

Somebody made a version of Conway’s Game of Life using nothing but checkboxes, which is very cool and you should check it out.

And finally, we’ve been doing an unexpected amount of automotive DIY repairs these days, meaning we spend a lot of time trolling around for parts. Here’s something we didn’t expect to see offered by a national retailer, but that we’d love to find a use for. If it ever comes back in stock we just might pick one up.

You might think Google Glass was an innovative idea, but [Allison Marsh] points out that artist [Lisa Krohn] imagined the Cyberdesk in 1993. Despite having desk in the name, the imagined prototype was really a wearable computer. Of course, in 1993, the technology wasn’t there to actually build it, but it does look like [Krohn] predicted headgear that would augment your experience.

Unlike Google Glass, the Cyberdesk was worn like a necklace. There are five disk-like parts that form a four-key keyboard and something akin to a trackpad. There were two models built, but since they were nonfunctional, they could have any imagined feature you might like. For example, the system was supposed to draw power from the sun and your body, something practical devices today don’t really do, either.

She also imagined a wrist-mounted computer with satellite navigation, a phone, and more. Then again, so did [Chester Gould] when he created Dick Tracy. The post also talks about a more modern reimagining of the Cyberdesk last year.

While this wasn’t a practical device, it is a great example of how people imagine the future. Sometimes, they miss the mark, but even then, speculative art and fiction can serve as goals for scientists and engineers who build the actual devices of the future.

We usually think about machines augmenting our intelligence and senses, but maybe we should consider more physical augmentation. We do appreciate seeing designs that are both artistic and functional.

If you’ve ever bought a modchip that adds features to your game console, you might have noticed sanded-off IC markings, epoxy blobs, or just obscure chips with unknown source code. It’s ironic – these modchips are a shining example of hacking, and yet they don’t represent hacking culture one bit. Usually, they are more of a black box than the console they’re tapping into. This problem has plagued the original XBOX hacking community, having them rely on inconsistent suppliers of obscure boards that would regularly fall off the radar as each crucial part went to end of life. Now, a group of hackers have come up with a solution, and [Macho Nacho Productions] on YouTube tells us its story – it’s an open-source modchip with an open firmware, ModXO.

Like many modern modchips and adapters, ModXO is based on an RP2040, and it’s got a lot of potential – it already works for feeding a BIOS to your console, it’s quite easy to install, and it’s only going to get better. [Macho Nacho Productions] shows us the modchip install process in the video, tells us about the hackers involved, and gives us a sneak peek at the upcoming features, including, possibly, support for the Prometheos project that equips your Xbox with an entire service menu. Plus, with open-source firmware and hardware, you can add tons more flashy and useful stuff, like small LCD/OLED screens for status display and LED strips of all sorts!

If you’re looking to add a modchip to your OG XBOX, it looks like the proprietary options aren’t much worth considering anymore. XBOX hacking has a strong community behind it for historical reasons and has spawned entire projects like XBMC that outgrew the community. There’s even an amazing book about how its security got hacked. If you would like to read it, it’s free and worth your time. As for open-source modchips, they rule, and it’s not the first one we see [Macho Nacho Productions] tell us about – here’s an open GameCube modchip that shook the scene, also with a RP2040!

If you ever encounter a British engineer of a certain age, the chances are that even if they use a modern DMM they’ll have a big boxy multimeter in their possession. This is the famous Avo 8, in its day the analogue multimeter to have. Of course it wasn’t the only AVO product, and [Thomas Scherrer OZ2CPU] is here with another black box sporting an AVO logo. This one’s an AC bridge, one of a series of models manufactured from the 1930s through to the late 1940s, and he treats us to a teardown and restoration of it.

Most readers will probably be familiar with the operation of a DC Wheatstone Bridge in which two resistances can be compared, and an AC bridge is the same idea but using an AC source. A component under test is attached to one set of terminals while one with a known value is put on the other, and the device can then be adjusted for a minimum reading on its meter to achieve a state of balance. The amount by which it is adjusted can then be used as a measure of the difference between the two parts, and thus the value of an unknown part can be deduced.

In the case of this AVO the AC is the 50Hz (remembering that this is a British instrument) mains frequency, and the reading from the bridge is taken via a single tube amplifier to a rectifier circuit and the meter. Inside it’s a treasure trove of vintage parts with an electrolytic capacitor that looks as though it might not be original, with a selenium rectifier and a copper oxide signal diode in particular catching our eye. This last part is responsible for some reading anomalies, but after cleaning and lubricating all the switches and bringing up the voltage gently, he’s rewarded with a working bridge. You can see the whole story in the video below the break.

Test equipment from this era is huge, so perhaps not all of you have the space for something like this. Some of us have been known to own other AVO products though.

Did you know you can get a “smart bed” that tracks your sleep, breathing, heart rate, and even regulates the temperature of the mattress? No? Well, you can get root access to one, too, as [Dillan] shows, and if you’re lucky, find a phone-home backdoor-like connection. The backstory to this hack is pretty interesting, too!

You see, a Sleep Number bed requires a network connection for its smart features, with no local option offered. Not to worry — [Dillan] wrote a Homebridge plugin that’d talk the cloud API, so you could at least meaningfully work with the bed data. However, the plugin got popular, Sleep Number didn’t expect the API to be that popular. When they discovered the plugin, they asked that it be shut down. Tech-inclined customers are not to be discouraged, of course.

Taking a closer look at the hardware, [Dillan] found a UART connection and dumped the flash, then wrote an extensive tutorial on how to tap into your bed’s controller, which runs Linux, and add a service you can use locally to query bed data and control the bed – just like it should have been from the beginning. Aside from that, he’s found a way to connect this hub to a network without using Sleep Number’s tools, enabling fully featured third-party use – something that the company doesn’t seem to like. Another thing he’s found is a reverse SSH tunnel back into the Sleep Number network.

Now, it can be reasonable to have a phone-home tunnel, but that doesn’t mean you want it in your personal network, and it does expose a threat surface that might be exploited in the future, which is why you might want to know about it. Perhaps you’d like to use Bluetooth instead of WiFi. Having this local option is good for several reasons. For example, having your smart devices rely on the manufacturer’s server is a practice that regularly results in perma-bricked smart devices, though we’ve been seeing some examples of dedicated hackers bringing devices back to life. Thanks to this hack, once Sleep Number shutters, is bought out, or just wants to move on, their customers won’t be left with a suddenly dumbed-down bed they can no longer control.

[Header image courtesy of Sleep Number]

When we think about sending an STL off on the Internet for processing, we usually want someone to print it for us or we want mesh repair. But [Chuck] found an interesting project on GitHub from [Andrew Sink] that will let you add a variable amount of twist to any STL and then return it to you for printing or whatever else you use STLs for. If you don’t get what we mean, check out the video below.

The site that does the work initially loads a little gnome figure if you are too lazy to upload your own model. That’s perfect, though, because the little guy is a good example of why you might want to twist a model. With just a little work, you can make the gnome look in one direction or even look behind him.

[Chuck] shows how to use the tool for artistic effect by twisting his standard cube logo. The result is something that looks like it would be difficult to create, but could hardly be easier. The tool lets you rotate the object, too, so you can get the twist effect in the right orientation for what you want to accomplish. A great little tool for making more artistic 3D prints without learning new software. If you want some fun, you can try the version that uses sound from your microphone to control the twist.

If you’d rather twist in CAD, we can help. If you really want artsy 3D printing, you probably need to learn Blender.

Cardboard is a surprisingly durable material, especially in its corrugated form. It’s extremely lightweight for its strength, is easy to work, can be folded and formed into almost any shape, is incredibly inexpensive, and when it has done its duty it can be recycled back into more paper. For these reasons, it’s often used in packaging material but it can be used to build all kinds of things outside of ensuring that products arrive at their locations safely. This working cardboard record player is one example.

While the turntable doesn’t have working records in the sense that the music is etched into them like vinyl, each has its own RFID chip embedded that allows the ESP32 in the turntable’s body to identify them. Each record corresponds to a song stored on an SD card that instructs the ESP32 to play the appropriate song. It also takes care of spinning the record itself with a small stepper motor. There are a few other details on this build that tie it together too, including a movable needle arm held on with a magnet and a volume slider.

As far as a building material goes, cardboard is fairly underrated in our opinion. Besides small projects like this turntable, we’ve also seen it work as the foundation for a computer, and it even has the strength and durability to be built into a wall or even used as shelving material. And, of course, it’s a great material to use when prototyping new designs.

There are so many new cool MCUs coming out, and you want to play with all of them, but, initially, they tend to be accessible as bare chips. Devboards might be hard to get, not expose everything, or carry a premium price. [Willmore] has faced this problem with an assortment of new WCH-made MCUs, and brings us all a solution – a universal board for TSSOP20-packaged MCUs, breadboard-friendly and adaptable to any pinout with only a few jumpers on the underside.

The board brings you everything you might want from a typical MCU breakout – an onboard 3.3V regulator, USB series resistors, a 1.5K pullup, decoupling capacitors, and a USB-C port. All GPIOs are broken out, and there’s a separate header you can wire up for all your SWD/UART/USB/whatever needs – just use the “patch panel” on the bottom of the board and pick the test points you want to join. [Willmore] has used these boards for the CH32Vxxx family, and they could, no doubt, be used for more – solder your MCU on, go through the pin table in the datasheet, do a little point-to-point wiring, and you get a pretty functional development board.

Everything is open-source – order a few of these boards from your fab of choice, and you won’t ever worry about a breakout for a TSSOP20 MCU or anything that would fit the same footprint. It could even be used in a pinch for something like an I2C GPIO expander. This is also a technique worth keeping in mind – a step above the generic footprint breakouts. Looking for more universal breakouts to keep? Here’s one for generic LCD/OLED panel breakouts.

As a result of the European Union’s push for greater repairability of consumer devices like smartphones, Apple sees itself forced to make the batteries in the iPhone user-replaceable by 2027. Reportedly, this has led Apple to look at using electroadhesion rather than conventional adhesives which require either heat, isopropyl alcohol, violence, or all of the above to release. Although details are scarce, it seems that the general idea would be that the battery is wrapped in metal, which, together with the inside of the metal case, would allow for the creation of a cationic/anionic pair capable of permanent adhesion with the application of a low-voltage DC current.

This is not an entirely wild idea. Tesa has already commercialized it in the electrical debonding form of its Debonding on Demand product. This uses a tape that’s applied to one side of the (metal) surfaces, with a 5 bar pressure being applied for 5 seconds. Afterwards, the two parts can be released again without residue as shown in the above image. This involves applying a 12V DC voltage for 60 seconds, with the two parts afterward removable without force.

Tesa markets this right alongside the pull tab adhesive strips which are currently all the rage in smartphones, with the opinions on pull strips during battery replacement strongly divided. A bottle of IPA is always good to have nearby when a pull tab inevitably snaps off and you have to pry the battery loose. In that regard electroadhesion for debonding would make life significantly easier since the times when batteries were not a structural part of smartphones are unlikely to return no matter how much we might miss them.

We covered electroadhesion previously, as you can make just about anything stick to anything, including biological tissues to graphite and metal, with potentially interesting applications in robotics and medicine.

When choosing a low-level language, it’s hard to beat the efficiency of Forth while also maintaining some amount of readability. There are open source options for the language which makes it accessible, and it maintains its prevalence in astronomical and other embedded systems for its direct hardware control and streamlined use of limited resources even though the language started over 50 years ago. Unlike 50 years ago, though, you can now take your own self-contained Forth programmer on the go with you.

The small computer is built on a design that [Dennis] built a while back called my4TH which has its own dedicated 8-bit CPU and can store data in a 256 kB EEPROM chip. Everything else needed for the computer is built in as well but that original design didn’t include a few features that this one adds, most notably a small 40×4 character LCD and a keyboard. The build also adds a case to tie everything together, with ports on the back for I2C and power plus an RS232 port. An optional battery circuit lets the computer power up without an external power supply as well.

Part of the appeal of Forth for systems like this is that it includes an interpreter and compiler in addition to the programming language itself, meaning that it has everything needed for a usable computer system built right in. For some more details on this unique language, or if you’d like to explore below the world of Python or C, check out [Elliot]’s discussion on the “hacker’s language.”. While Forth can tackle big problems, it can fit on tiny machines, too.

Hydraulics are incredibly versatile, but due to the pressures at which they operate, they are also rather expensive and not very DIY-friendly. This isn’t to say that you cannot take a fair shot at a halfway usable 3D-printed set of hydraulics, as [Indeterminate Design] demonstrates in a recent video. Although not 100% 3D-printed, it does give a good idea of how far you can push plastic-based additive manufacturing in this field.

Most interesting is the integration of the gear pump, 4-way selector valve, and relief valve into a single structure, which was printed with a resin printer (via the JLC3DP 3D print service). After bolting on the (also 3D printed) clear reservoir and assembling the rest of the structure including the MR63 ball bearings, relief spring valve, and pneumatic fittings it was ready to be tested. The (unloaded) gear pump could pump about 0.32 L/minute, demonstrating its basic functionality.

For the hydraulic cylinder, mostly non-3D printed parts were used, with a brass cylinder forming the main body. During these initial tests, plain water was used, followed by CHF11 hydraulic oil, with a pressure of about 1.3 bar (19 PSI) calculated afterward. This fairly low pressure is suspected to be caused by leaky seals (including the busted shaft seal), but as a basic proof of concept, it provides an interesting foundation for improvements.

Want a primer on hydraulics? We got you. MIT likes 3D printing with hydraulics, too (dead link, but the underlying paper link is still good).

Last week, [Al Williams] wrote up a his experience with a book that provided almost too much detailed information on how to build a DIY x-ray machine for his (then) young soul to bear. He almost had to build it! Where the “almost” is probably both a bummer because he didn’t have an x-ray machine as a kid, but also a great good because it was a super dangerous build, of a typical sort for the 1950s in which it was published.

Part of me really loves the matter-of-factness with which “A Boy’s First Book of Linear Accelerators” tells you how you (yes you!) can build a 500 kV van der Graff generator. But at the same time, modern me does find the lack of safety precautions in many of these mid-century books to be a little bit spooky. Contrast this with modern books where sometimes I get the feeling that the publisher’s legal team won’t let us read about folding paper airplanes for fear of getting cut.

A number of us have built dangerous projects in our lives, and many of us have gotten away with it. Part of the reason that many of us are still here is that we understood the dangers, but I would be lying if I said that I always fully understood them. But thinking about the dangers is still our first and best line of defense. Humility about how well you understand all of the dangers of a certain project is also very healthy – if you go into it keeping an eye out for the unknown unknowns, you’re in better shape.

Safety isn’t avoiding danger, but rather minimizing it. When we publish dangerous hacks, we really try to at least highlight the most important hazards so that you know what to look out for. And over the years, I’ve learned a ton of interesting safety tricks from the comments and fellow hackers alike. My ideal, then, is the spirit of the 1950s x-ray book, which encourages you to get the hack built, but modernized so that it tells you where the dangers lie and how to handle them. If you’re shooting electrons, shouldn’t the book also tell you how to stay out of the way?

Developing free and open source software can be a thankless experience. Most folks do it because it’s something they’re passionate about, with the only personal benefit being the knowledge that there are individuals out there who found your work useful enough to download and install. So imagine how you’d feel if it turns out somebody was playing around with the figures, and the steady growth in the number of installs you thought your software had turned out to be fake.

That’s what happened just a few days ago to OctoPrint developer [Gina Häußge]. Although there’s no question that her software for remotely controlling and monitoring 3D printers is immensely popular within the community, the fact remains that the numbers she’s been using to help quantify that popularity have been tampered with by an outside party. She’s pissed, and has every right to be.

[Gina] discovered this manipulation on June 26th after taking a look at the publicly available usage stats on data.octoprint.org. She noticed that an unusually high number of instances appeared to be running an old OctoPrint release, and upon closer inspection, realized what she was actually seeing was a stream of bogus data that was designed to trick the stat counter. Rolling back the data, she was able to find out this spam campaign has been going on since late 2022. Tens of thousands of the users she thought she’d gained over the last two years were in fact nothing more than garbage spit out by some bot. But why?

Here’s where it gets interesting. Looking at the data being reported by these fake OctoPrint instances, [Gina] could tell the vast majority of them claimed to be running a specific plugin: OctoEverywhere. The perpetrators were clever enough to sprinkle in a random collection of other popular plugins along with it, but this specific plugin was the one most of them had in common. Sure enough this pushed OctoEverywhere to the top of the charts, making it seem like it was the most popular plugin in the community repository.

So what do the developers of OctoEverywhere have to say for themselves? In a statement that [Gina] posted on the OctoPrint blog, they claim they were able to determine a member of the community had performed the stat manipulation of their own accord, but as of this writing are unwilling to release this individual’s identity. A similar statement now appears on the OctoEverywhere website.

On June 27th, Gina Häußge, the developer behind OctoPrint, informed us of an incident involving the OctoPrint usage stats. Gina had observed that the stats were being manipulated to boost OctoEverywhere’s rankings.

We took the report very seriously and quickly started an investigation. Using private community channels, we determined a community member was responsible for manipulating the OctoPrint stats. We had a private conversation with the individual, who didn’t realize the impact they were having but apologized and promised never to do it again.

From a journalistic perspective, it would be inappropriate for us to leap to any conclusions based on the currently available information. But we will say this…we’ve heard more convincing stories on a kindergarten playground. Even if we take the statement at face value, the fact that they were able to figure out who was doing this within 48 hours of being notified would seem to indicate this person wasn’t exactly a stranger to the team.

In any event, the bogus data has now been purged from the system, and the plugin popularity charts are once again showing accurate numbers. [Gina] also says some safeguards have been put into place to help prevent this sort of tampering from happening again. As for OctoEverywhere, it slid back to its rightful place as the 6th most popular plugin, a fact that frankly makes the whole thing even more infuriating — you’d think legitimately being in the top 10 would have been enough.

On Mastodon, [Gina] expressed her disappointment in being fooled into thinking OctoPrint was growing faster than it really was, which we certainly get. But even so, OctoPrint is a wildly popular piece of software that has become the cornerstone of a vibrant community. There’s no question that her work has had a incredible impact on the world of desktop 3D printing, and while this turn of events is frustrating, it will ultimately be little more than a footnote in what is sure to be a lasting legacy.

Fusion power has long held the promise of delivering near-endless energy without as many unfortunate side effects as nuclear fission. But despite huge investment and some fascinating science, the old adage about practical power generation being 20 years away seems just as true as ever. But is that really the case? [Brian Potter] has written a review article for Construction Physics, which takes us through the decades of fusion research.

For a start, it’s fascinating to learn about the many historical fusion process, the magnetic pinch, the stelarator, and finally the basis of many modern reactors, the tokamak. He demonstrates that we’ve made an impressive amount of progress, but at the same time warns against misleading comparisons. There’s a graph comparing fusion progress with Moore’s Law that he debunks, but he ends on a positive note. Who knows, we might not need a Mr. Fusion to arrive from the future after all!

Fusion reactors are surprisingly easy to make, assuming you don’t mind putting far more energy in than you’d ever receive in return. We’ve featured more than one Farnsworth fusor over the years.

Over the last few years, it’s been increasingly common for concertgoers to be handed a light-up bracelet from PixMob that synchronizes with the others in the crowd to turn the entire audience into a music visualizer. They’re a clever way of enhancing the concert experience, but unfortunately, they don’t do anything once you leave the show. Or at least, that used to be the case.

We’ve seen efforts to reverse engineer the IR (and occasionally radio) signals that drive these PixMob devices, but since we checked in last it seems like things have gotten a lot easier for the home gamer. [David Pride] has recently posted a brief write-up that shows how quickly and easily it is to get these devices fired up using nothing more exotic than an Arduino, an IR LED, and an audio sensor module.

With the audio sensor module connected to the Arduino’s digital input and the IR LED wired to digital out, all you need to do is flash firmware to the board and start playing some beats. The source code [David] has provided is a a remixed version of what’s previously been published by [Carlos Ganoza], which, in this case, has been tweaked to make the lighting patterns less random.

Presumably, this is to make the devices behave more like they do during an actual concert, but since nobody at Hackaday is cool enough to have seen a live musical performance in the last decade, we’re not really sure. All we can say is that the effect looks pretty sweet in the demo video.

Back in 2019, we saw a teardown of an early PixMob device, and by 2022, the efforts to reverse engineer their IR control protocol were well underway. We’re glad to see things have progressed to the point that you can piece together a transmitter from what’s in the parts bin, as it means at least some of these devices will have a lifespan longer than a single concert.

There’s a pleasing retro analogue experience to shooting Super 8 film, giving as it does the feel of a 1970s home movie to your work. But once you’ve had the film developed, there’s a need for a projector to enjoy the result. Far better to digitize it for a more modern viewing and editing experience. [Elbert] has made a digitizer for 8mm film which takes the best approach, snapping each frame individually to be joined together in a video file as a whole.

The frame of the device is 3D printed, but some parts of a film transport must be higher quality than a printed part can deliver. These, in particular the sprockets, are salvaged from a film viewer, and the movement is powered by a set of stepper motors. The steppers are controlled by an ESP32, and the optics are provided by a USB microscope. All this is hooked up to a PC which grabs each image, and finally stitches them all together using ffmpeg.

As anyone who has dabbled in 8mm film will tell you, there is a lot in the quality of a film digitizer, and it’s often worth paying for a professional job from someone aimed at the film-making world rather than you local photographic print booth. It would be interesting to take a look at this device, and see whether its quality is worth pursuing. After all, some of us have been known to dabble in 8mm film.