Dice are about the simplest machines possible, and they’ve been used since before recorded history to generate random numbers. But no machine is so simple that a little needless complexity can’t make it better, as is the case with this mechanical spinning dice. Or die. Whatever.

Inspiration for the project came from [Attoparsec]’s long history with RPG and tabletop games, which depend on different kinds of dice to generate the randomness that keeps them going — that and the fortuitous find of a seven-segment flip-dot display, plus the need for something cool to show off at OpenSauce. The flip-dot is controlled by an array of neodymium magnets with the proper polarity to flip the segments to the desired number. The magnets are attached to an aluminum disk, with each array spread out far enough to prevent interference. [Attoparsec] also added a ring of magnets to act as detents that lock the disk into a specific digit after a spin.

The finished product ended up being satisfyingly clicky and suitably random, and made a good impression at OpenSauce. The video below documents the whole design and build process, and includes some design dead-ends that [Attoparsec] went down in pursuit of a multiple-digit display. We’d love to see him revisit some of these ideas, mechanically difficult though they may be. And while he’s at it, maybe he could spice up the rolls with a little radioactivity.

There have been a couple of high-profile solar eclipses lately, but like us, you probably missed the news of the one that passed over Munich in 2019. And every day since then, in fact, unless you were sitting in a particular spot: the couch of one [Bernd Kraus], who has his very own personal eclipse generator.

We’ll attempt to explain. Living in an apartment with a gorgeous western view of Munich is not without its cons, chief among which is the unobstructed exposure to the setting sun. Where most people would opt for a window treatment of some sort to mitigate this, [Bernd] felt that blotting out the entire view was a heavy-handed solution to the problem. His solution is a window-mounted X-Y gantry that dangles a cutout of the moon in just the right place to blot out the sun. An Arduino uses the time and date to calculate the position of the sun as it traverses the expansive window and moves the stepper motors to keep the moon casting its shadow in just the right place: on his face as he sits in his favorite spot on the couch.

There are a couple of time-lapse sequences in the video below, as well as a few shots of the hardware. We know this isn’t an actual coronagraph, but the effect is pretty cool, and does resemble an eclipse, at least in spirit. And it goes without saying that we applaud the unnecessary complexity embodied by this solution.

On the face of it, harnessing wind power to heat your house seems easy. In fact some of you might be doing it already, assuming you’ve got a wind farm somewhere on your local grid and you have an electric heat pump or — shudder — resistive heaters. But what if you want to skip the middleman and draw heat directly from the wind? In that case, wind-powered induction heating might be just what you need.

Granted, [Tim] from the Way Out West Blog is a long way from heating his home with a windmill. Last we checked, he didn’t even have a windmill built yet; this project is still very much in the experimental phase. But it pays to think ahead, and with goals of simplicity and affordability in mind, [Tim] built a prototype mechanical induction heater. His design is conceptually similar to an induction cooktop, where alternating magnetic fields create eddy currents that heat metal cookware. But rather than using alternating currents through large inductors, [Tim] put 40 neodymium magnets with alternating polarity around the circumference of a large MDF disk. When driven by a drill press via some of the sketchiest pullies we’ve seen, the magnets create a rapidly flipping magnetic field. To test this setup, [Tim] used a scrap of copper pipe with a bit of water inside. Holding it over the magnets as they whiz by rapidly heats the water; when driven at 1,000 rpm, the water boiled in about 90 seconds. Check it out in the video below.

It’s a proof of concept only, of course, but this experiment shows that a spinning disc of magnets can create heat directly. Optimizing this should prove interesting. One thing we’d suggest is switching from a disc to a cylinder with magnets placed in a Halbach array to direct as much of the magnetic field into the interior as possible, with coils of copper tubing placed there.

When a ransomware attack targets something like a hospital, it quickly becomes a high-profile event that understandably results in public outrage. Hospitals are supposed to be backstops for society, a place to go when it all goes wrong, and paralyzing their operations for monetary gain by taking over their information systems is just beyond the pale. Tactically, though, it makes sense; their unique position in society seems to make it more likely that they’ll pay up.

Which is why the ongoing cyberattack against car dealerships is a little perplexing — can you think of a less sympathetic victim apart from perhaps the Internal Revenue Service? Then again, we’re not in the ransomware business, so maybe this attack makes good financial sense. And really, judging by the business model of the primary target of these attacks, a company called CDK Global, it was probably a smart move. We had no idea that there was such a thing as a “Dealer Management System” that takes care of everything from financing to service, and that shutting down one company’s system could cripple an entire industry, but there it is.

Water may seem like the enemy for anyone who gets in trouble while swimming, but it’s really time that they’re fighting. Even a strong swimmer can quickly become exhausted fighting wind and waves; add in the hypothermia that’ll eventually set in even in water as warm as a bath, and the difference between life and death can come down to seconds. Getting help to a floundering swimmer isn’t easy, though, as lifeguards can only swim so fast.

But a new remotely operated rescue boat aims to change that, by getting to someone in trouble as fast as possible. Named EMILY, for “Emergency Integrated Lifesaving Lanyard,” the unit is a compact electrically powered rescue boat that can be rapidly deployed by lifeguards, who remotely pilot it to the victim. The boat’s deck is covered with what looks like survival gear, most of which would probably be of more use to the lifeguard upon their arrival than to the swimmer, who would likely just use the boat for flotation. As such, this makes way more sense than sending a drone out there, which at best could only drop a life ring. At $12,000 a piece, these boats aren’t cheap, but for the families who lost their kids in 2022 who donated them, they probably seem like quite a bargain. Here’s hoping they pay off.

We can’t be sure, but we’ve got a vague memory of playing a game called Lunar Landing way back in the day. It would likely have been on a TRS-80 in our local Radio Shack store, and if memory serves, we never got particularly good at the text-based simulator. Happily, though, we can now at least attempt to foist our lack of skills off on a 55-year-old bug in the software. Recently discovered by the excellently named Martin C. Martin while trying to optimize the fuel burn schedule to land softly with the most fuel remaining — the key to a high score, as we recall — the bug makes it so a tiny change in burn rate gives wildly different results. The post-mortem of his search and the analysis of the code, written by high school student Jim Storer only months after the real moon landing in 1969, is very interesting. We especially appreciated the insights into how Storer wrote it, revealed via personal communications. It’s a great look at a piece of computer history, and hats off to both Storer and Martin — although we haven’t seen a CVE posted for this yet.

We know that Minitel terminals are highly collectible, but this is ridiculous. Granted, the Minitel occupies a unique place in computer history, and the boxy design of the original CRT and keyboard terminal was not without its charms. But this particular terminal seems to have had a Very Bad Day in the recent past and is now on the chopping block for a mere €430. To be fair, the eBay user in France has listed the Dalí-esque Minitel as an objet d’art; at that price, we’d like to at least get some usable parts from it to fix other terminals, but that doesn’t seem likely. Somebody will probably buy it, though — no accounting for taste.

And finally, AnimaGraffs is back, this time with a deep dive into the Bell 407 helicopter. We’ve been big fans of his work for a while and have featured a few of his videos in this space, including his look inside the SR-71 Blackbird spy plane. The new video is richly detailed and includes not only the engineering that goes into rotorcraft but also the physics that makes them work and makes them so challenging to fly. Enjoy!

Nobody doubts the utility of the Arduino Nano and its many clones, and chances are good you’ve got at least one or two of the tiny dev boards within arm’s reach right now. But as small as it is, the board still takes up a fair amount of real estate, especially on solderless breadboards during the prototyping phase of a project. Wouldn’t it be nice to shrink down the Nano just a bit and regain a couple of rows for plugging in components and jumpers?

It looks like [Albert van Dalen] thought so, and he managed to get a Nano’s functionality — and then some — onto a DIP-26 footprint. The aptly named “Nano DIP,” which at 33 mm x 10 mm — about the same size as the ATmega328 on the Arduino Uno — will tickle the miniaturization fans out there. The board is built around an ATtiny3217 and has almost all of the Nano’s features, like a USB port, reset button, built-in LEDs, 5 V regulator, and preloaded bootloader. Its big extra feature is the 350-kilosamples-per-second 8-bit DAC, while sacrificing external crystal pins and a 3.3 V regulator.

To make the board cheap enough to manufacture, [Albert] elected a minimum component size of 0402, which made squeezing all the parts onto the board challenging. The MCU barely fits between the header pin pads, and the Micro USB jack had to be a vertical-mount type. It does the business, though, so if you’re looking to free up a little breadboard space, check it out.

In a lot of ways, Etch-A-Sketch is the perfect toy; simple, easy to use, creative, endlessly engaging, and as a bonus, it’s completely mechanical. We find that last attribute to be a big part of its charm, but that’s not to say an electronic version of the classic toy can’t be pretty cool, especially when it’s done without the aid of a microcontroller.

This is one of those “because I can” projects that we always find so interesting, and more so because it wasn’t entirely clear to [BigZaphod] that he had the skills to pull it off. While his initial design centered around a bunch of 8×8 LED matrix displays and a 256×4-bit RAM chip, the rest of it was a lot of hand-waving. After a few experiments with addressing the LEDs, [Zaphod] started filling in the blanks with a refresh circuit using a 555 — naturally — and a pair of counters. Properly debounced encoders for the horizontal and vertical controls came next, along with more counters to track the cursor and a host of other circuits that ended up looking like a “one of each” selection from the 7400-series catalog.

While we do wish for a schematic on this one, it’s still a pretty enjoyable video, and the end product seems to work really well. The electronic version has a few features the original lacks, such as wrapping the cursor to the other side of the screen. We’d imagine that the buttons on the encoders could be put to work, too; perhaps a click could make it so you can move the cursor without leaving a trail behind. That might be a challenge to execute in logic, but then again, that was the point of the whole thing.

Still jonesing for that mechanical Etch-A-Sketch experience? Not a problem.

OK, it’s official: the Quansheng UV-K5 is the king of hackable ham radios — especially now that a second version of the all-band hardware and firmware mod has been released, not to mention a new version of the radio.

If you need to get up to speed, check out our previous coverage of the all-band hack for the UV-K5, in which [Paul (OM0ET)] installs a tiny PCB to upgrade the radio’s receiver chip to an Si4732. Along with a few jumpers and some component replacements on the main board, these hardware mods made it possible for the transceiver, normally restricted to the VHF and UHF amateur radio bands, to receive everything down to the 20-meter band, in both AM and single-sideband modulations.

The new mod featured in the video below does all that and more, all while making the installation process slightly easier. The new PCB is on a flexible substrate and is considerably slimmer, and also sports an audio amplifier chip, to make up for the low audio output on SSB signals of the first version. Installation, which occupies the first third of the video below, is as simple as removing one SMD chip from the radio’s main board and tacking the PCB down in its footprint, followed by making a couple of connections with very fine enameled wire.

You could load the new firmware and call it a day at that point, but [Paul] decided to take things a step further and install a separate jack for a dedicated HF antenna. This means sacrificing the white LED on the top panel, which isn’t much of a sacrifice for most hams, to make room for the jack. Most of us would put a small SMA jack in, but [Paul] went for a BNC, which required some deft Dremel and knife work to fit in. He also used plain hookup wire to connect the jack, which sounds like a terrible idea; we’d probably use RG-316, but his mod didn’t sound that bad at all.

Keen to know more about the Quansheng UV-K5? Dive into the reverse-engineered schematics.

Thanks to [Sam] for the heads up on this one.

With few exceptions, power transmission is a field where wobbling is a bad thing. We generally want everything running straight and true, with gears and wheels perfectly perpendicular to their shafts, with everything moving smoothly and evenly. That’s not always the case, though, as this pericyclic gearbox demonstrates.

Although most of the components in [Retsetman] model gearboxes seem familiar enough — it’s mostly just a collection of bevel gears, like you’d see inside a differential — it’s their arrangement that makes everything work. More specifically, it’s the shaft upon which the bevel gears ride, which has a section that is tilted relative to the axis of the shaft. It’s just a couple of degrees, but that small bit of inclination, called mutation, makes the ring gear riding on it wobble as the shaft rotates, allowing it to mesh with one or more ring gears that are perpendicular to the shaft. This engages a few teeth at a time, transferring torque from one gear to another. It’s easier to visualize than it is to explain, so check out the video below.

Gearboxes like these have a lot of interesting properties, with the main one being gear ratio. [Retsetman] achieved a 400:1 ratio with just 3D printed parts, which of course impose their own limitations. But he was still able to apply some pretty serious torque. The arrangement is not without its drawbacks, of course, with the wobbling bits naturally causing unwelcome vibrations. That can be mitigated to some degree using multiple rotatins elements that offset each other, but that only seems to reduce vibration, not eliminate it.

[Retsetman] is no stranger to interesting gearboxes, of course, with his toothless magnetic gearboxes coming to mind. And this isn’t the only time we’ve seen gearboxes go all wobbly, either.

Thanks to [Keith Olson] for the tip.

While we generally prefer to bring our readers as much information about a project as possible, sometimes we just have to go with what we see. That generally happens with new projects and work in progress, but it can also happen with old projects. Sometimes very old indeed, as is the case with this digital sampling unit for analog oscilloscopes, circa 1979.

We’ve got precious little to go on with this one other than the bit of eye candy in the video tour below and its description. Luckily, we’ve had a few private conversations with its maker, [Mitsuru Yamada], over the years, enough to piece together a little of the back story here — with apologies for any wrong assumptions, of course.

Built when he was only 19, this sampler was an attempt to build something that couldn’t be bought, at least not for a reasonable price. With no inexpensive monolithic analog-to-digital converters on the market, he decided to roll his own. A few years back he recreated the core of that with his all-discrete successive approximation ADC.

The sampler shown below has an 8-bit SAR ADC using discrete CMOS logic and enough NMOS memory to store 256 samples. You can see the ADC and memory cards in the homebrew card cage made from aluminum angle stock. The front panel has a ton of controls and sports a wide-range attenuator, DC offset, and trigger circuit with both manual and automatic settings.

It’s an impressive build, especially for a 19-year-old with presumably limited resources. We’ve reached out to [Yamada-san] in the hope that he’ll be able to provide more details on what’s under the hood and if this still works after all these years. We’ll pass along whatever we get, but in the meantime, enjoy.

Attention, slackers — if you do remote work for a financial institution, using a mouse jiggler might not be the best career move. That’s what a dozen people learned this week as they became former employees of Wells Fargo after allegedly being caught “simulating keyboard activity” while working remotely. Having now spent more than twice as many years working either hybrid or fully remote, we get it; sometimes, you’ve just got to step away from the keyboard for a bit. But we’ve never once felt the need to create the “impression of active work” during those absences. Perhaps that’s because we’ve never worked in a regulated environment like financial services.

For our part, we’re curious as to how the bank detected the use of a jiggler. The linked article mentions that regulators recently tightened rules that require employers to treat an employee’s home as a “non-branch location” subject to periodic inspection. More than enough reason to quit, in our opinion, but perhaps they sent someone snooping? More likely, the activity simulators were discovered by technical means. The article contains a helpful tip to avoid powering a jiggler from the computer’s USB, which implies detecting the device over the port. Our guess is that Wells tracks mouse and keyboard activity and compares it against a machine-learning model to look for signs of slacking.

Speaking of the intersection of soulless corporate giants and AI, what’s this world coming to when AI walks you right into an online scam? That’s what happened to a Canadian man recently when he tried to get help moving Facebook to his new phone. He searched for a customer service number for Facebook and found one listed, but thought it would be wise to verify the number. So he pulled up the “Meta AI”-powered search tool in Facebook Messenger and asked if the number was legit. “No problem,” came the reply, so he called the number and promptly got attacked by the scammers on the other end, who within minutes used his PayPal account to buy $500 worth of Apple gift cards. From the sound of it, the guy did everything he should have to protect himself, at least up to a point. But when a company’s chatbot system gives you bad information about their own customer support, things like this are going to happen.

Just a reminder that we’re deep into con season now. Open Sauce should be just about wrapped up by the time this gets published, and coming up the week after is Teardown 2024 in Portland. The schedule for that has been released, which includes a workshop on retrocomputing with the “Voja4” Supercon badge. A little further on into the summer and back on the East Coast will be HOPE XV, which still has some tickets left. The list of speakers for that one looks pretty good, as does the workshop roundup.

And finally, if you have some STL models in need of a little creative mutilation, try out this STL twister online tool. It’s by our friend [Andrew Sink], who has come up with a couple of other interesting 3D tools, like the Banana for Scale tool and the 3D Low-Poly Generator. The STL Twister does pretty much what it says and puts the screws to whatever STL model you drop on it. The MakerBot Gnome mascot that pops up by default is a particularly good model for screwifying. Enjoy!

We may be a bit biased, but the storage media of yesteryear has so much more personality than that of today. Yes, it’s a blessing to have terabyte SD cards smaller than your pinky nail and be able to access its data with mind-boggling speed. But there’s a certain charm to a mass storage device that can potentially slice off your finger.

We’re overstating the dangers of the venerable paper tape reader, of course, a mass storage device that [David Hansel] recreated a few years back but we only just became aware of. That seems a bit strange since we’ve featured his Arduino-based Altair 8800 simulator, which is what this tape reader is connected to. Mechanically, the reader is pretty simple — just a wooden frame to hold the LEGO Technic wheels used as tape reels, and some rollers to guide the tape through a read head. That bit is custom-made and uses a pair of PCBs, one for LEDs and one for phototransistors. There are nine of each — eight data bits plus the index hole — and the boards are sandwiched together to guide the paper tape.

The main board has an ATmega328 which reads the parallel input from the read head and controls the tape motor. That part is important thanks to Altair Basic’s requirement for a 100- to 200-ms delay at the end of each typed line. The tape reader, which is just being used as sort of a keyboard wedge, can “type” a lot faster than that, so the motor speed is varied using PWM control as line length changes.

Thanks to [Stephen Walters] for the tip.

It didn’t take long for us to get an answer to the question nobody was asking: Can you use toilet paper as solder wick? And unsurprisingly, the answer is a resounding “No.”

Confused? If so, you probably missed our article a few days ago describing the repair of corroded card edge connectors with a bit of homebrew HASL. Granted, the process wasn’t exactly hot air solder leveling, at least not the way PCB fabs do it to protect exposed copper traces. It was more of an en masse tinning process, for which [Adrian] used a fair amount of desoldering wick to pull excess solder off the pins.

During that restoration, [Adrian] mentioned hearing that common toilet paper could be used as a cheap substitute for desoldering wick. We were skeptical but passed along the tip hoping someone would comment on it. Enter [KDawg], who took up the challenge and gave it a whirl. The video below shows attempts to tin a few pins on a similar card-edge connector and remove the excess with toilet paper. The tests are done using 63:37 lead-tin solder, plus and minus flux, and using Great Value TP in more or less the same manner you’d use desoldering braid. The results are pretty much what you’d expect, with charred toilet paper and no appreciable solder removal. The closest it comes to working is when the TP sucks up the melted flux. Stay tuned for the bonus positive control footage at the end, though; watching that legit Chemtronics braid do its thing is oddly satisfying.

So, unless there’s some trick to it, [KDawg] seems to have busted this myth. If anyone else wants to give it a try, we’ll be happy to cover it.

We’ve said it before and we’ll say it again: being able to build your own radios is the best thing about being an amateur radio operator. Especially low-power transmitters; there’s just something about having the know-how to put something on the air that’ll reach across the planet on a power budget measured in milliwatts.

This standalone WSPR beacon is a perfect example. If you haven’t been following along, WSPR stands for “weak-signal propagation reporter,” and it’s a digital mode geared for exploring propagation that uses special DSP algorithms to decode signals that are far, far down into the weeds; signal-to-noise ratios of -28 dBm are possible with WSPR.

Because of the digital nature of WSPR encoding and the low-power nature of the mode, [IgrikXD] chose to build a standalone WSPR beacon around an ATMega328. The indispensable Si5351 programmable clock generator forms the RF oscillator, the output of which is amplified by a single JFET transistor. Because timing is everything in the WSPR protocol, the beacon also sports a GPS receiver, ensuring that signals are sent only and exactly on the even-numbered minutes. This is a nice touch and one that our similar but simpler WSPR beacon lacked.

This beacon had us beat on performance, too. [IgrikXD] managed to hit Texas and Colorado from the edge of the North Sea on several bands, which isn’t too shabby at all with a fraction of a watt.

Thanks to [STR-Alorman] for the tip.

[via r/amateurradio]

If you’re like us, the oscilloscope on your bench is nothing special. The lower end of the market is filled with cheap but capable scopes that get the job done, as long as the job doesn’t get too far up the spectrum. That’s where fancier scopes with active probes might be required, and such things are budget-busters for mere mortals.

Then again, something like this open source 2 GHz active probe might be able to change the dynamics a bit. It comes to us from [James Wilson], who began tinkering with the design back in 2022. That’s when he learned about the chip at the center of this build: the BUF802. It’s a wide-bandwidth, high-input-impedance JFET buffer that seemed perfect for the job, and designed a high-impedance, low-capacitance probe covering DC to 2 GHz probe with 10:1 attenuation around it.

[James]’ blog post on the design and build reads like a lesson in high-frequency design. The specifics are a little above our pay grade, but the overall design uses both the BUF802 and an OPA140 precision op-amp. The low-offset op-amp buffers DC and lower frequencies, leaving higher frequencies to the BUF802. A lot of care was put into the four-layer PCB design, as well as ample use of simulation to make sure everything would work. Particularly interesting was the use of openEMS to tweak the width of the output trace to hit the desired 50 ohm impedance.

Right off the bat, we’ll stipulate that what [Adrian] is doing in the video below isn’t actual hot air solder leveling. But we thought the results of his card-edge connector restoration on a CGA video card from the early 80s was pretty slick, and worth keeping in mind for other applications.

The back story is that [Adrian], of “Digital Basement” YouTube fame, came across an original IBM video card from the early days of the IBM-PC. The card was unceremoniously dumped, probably due to the badly corroded pins on the card-edge bus connector. The damage appeared to be related to a leaking battery — the corrosion had that sickly look that seems to only come from the guts of batteries — leading him to try cleaning the formerly gold-plated pins. He chose naval jelly rust remover for the job; for those unfamiliar with this product, it’s mostly phosphoric acid mixed with thickeners and is used as a rust remover.

The naval jelly certainly did the trick, but left the gold-plated pins a little worse for the wear. Getting them back to their previous state wasn’t on the table, but protecting them with a thin layer of solder was easy enough. [Adrian] used liquid rosin flux and a generous layer of 60:40 solder, which was followed by removing the excess with desoldering braid. That worked great and got the pins on both sides of the board into good shape.

[Adrian] also mentioned a friend who recommended using toilet paper to wick up excess solder, but sadly he didn’t demonstrate that method. Sounds a little sketchy, but maybe we’ll give it a try. As for making this more HASL-like, maybe heating up the excess solder with an iron and blasting the excess off with some compressed air would be worth a try.

A few years back I wrote an “Ask Hackaday” article inviting speculation on the future of the physical plant of landline telephone companies. It started innocently enough; an open telco cabinet spotted during my morning walk gave me a glimpse into the complexity of the network buried beneath my feet and strung along poles around town. That in turn begged the question of what to do with all that wire, now that wireless communications have made landline phones so déclassé.

At the time, I had a sneaking suspicion that I knew what the answer would be, but I spent a good bit of virtual ink trying to convince myself that there was still some constructive purpose for the network. After all, hundreds of thousands of technicians and engineers spent lifetimes building, maintaining, and improving these networks; surely there must be a way to repurpose all that infrastructure in a way that pays at least a bit of homage to them. The idea of just ripping out all that wire and scrapping it seemed unpalatable.

With the decreasing need for copper voice and data networks and the increasing demand for infrastructure to power everything from AI data centers to decarbonized transportation, the economic forces arrayed against these carefully constructed networks seem irresistible. But what do the numbers actually look like? Are these artificial copper mines as rich as they appear? Or is the idea of pulling all that copper out of the ground and off the poles and retasking it just a pipe dream?

Phones To Cars

There are a lot of contenders for the title of “Largest Machine Ever Built,” but it’s a pretty safe bet that the public switched telephone network (PSTN) is in the top five. From its earliest days, the PSTN was centered around copper, with each and every subscriber getting at least one pair of copper wires connected from their home or business. These pairs, referred to collectively and somewhat loosely as the “local loop,” were gathered together into increasingly larger bundles on their way to a central office (CO) housing the switchgear needed to connect one copper pair to another. For local calls, it could all be done within the CO or by connecting to a nearby CO over copper lines dedicated to the task; long-distance calls were accomplished by multiplexing calls together, sometimes over microwave links but often over thick coaxial cables.

Fiber optic cables and wireless technologies have played a large part in making all the copper in the local loops and beyond redundant, but the fact remains that something like 800,000 metric tons of copper is currently locked up in the PSTN. And judging by the anti-theft efforts that Home Depot and other retailers are making, not to mention the increase in copper thefts from construction sites and other soft targets, that material is incredibly valuable. Current estimates are that PSTNs are sitting on something like $7 billion worth of copper.

That sure sounds like a lot, but what does it really mean? Assuming that the goal of harvesting all that largely redundant PSTN copper is to support decarbonization, $7 billion worth of copper isn’t really that much. Take EVs for example. The typical EV on the road today has about 132 pounds (60 kg) of copper, or about 2.5 times the amount in the typical ICE vehicle. Most of that copper is locked up in motor windings, but there’s a lot in the bus bars and wires needed to connect the batteries to the motors, plus all the wires needed to connect all the data systems, sensors, and accessories. If you pulled all the copper out of the PSTN and used it to do nothing but build new EVs, you’d be able to build about 13.3 million cars. That’s a lot, but considering that 80 million cars were put on the road globally in 2021, it wouldn’t have that much of an impact.

Farming the Wind

What about on the generation side? Thirteen million new EVs are going to need a lot of extra generation and transmission capacity, and with the goal of decarbonization, that probably means a lot of wind power. Wind turbines take a lot of copper; currently, bringing a megawatt of on-shore wind capacity online takes about 3 metric tons of copper. A lot of that goes into the windings in the generator, but that also takes into account the wire needed to get the power from the nacelle down to the ground, plus the wires needed to connect the turbines together and the transformers and switchgear needed to boost the voltage for transmission. So, if all of the 800,000 metric tons of copper currently locked up in the PSTN were recycled into wind turbines, they’d bring a total of 267,000 megawatts of capacity online.

To put that into perspective, the total power capacity in the United States is about 1.6 million megawatts, so converting the PSTN to wind turbines would increase US grid capacity by about 16% — assuming no losses, of course. Not too shabby; that’s over ten times the capacity of the world’s largest wind farm, the Gansu Wind Farm in the Gobi Desert in China.

There’s one more way to look at the problem, one that I think puts a fine point of things. It’s estimated that to reach global decarbonization goals, in the next 25 years we’ll need to mine at least twice the amount of copper that has ever been mined in human history. That’s quite a lot; we’ve taken 700 million metric tons of copper in the last 11,000 years. Doubling that means we’ve got to come up with 1.4 billion metric tons in the next quarter century. The 800,000 metric tons of obsolete PSTN copper is therefore only about 0.05% of what’s needed — not even a drop in the bucket.

Accepting the Inevitable

These are just a few examples of what could be done with the “Buried Fortune” of PSTN copper, as Bloomberg somewhat breathlessly refers to it in the article linked above. It goes without saying that this is just back-of-the-envelope math, and that a real analysis of what it would take to recycle the old PSTN copper and what the results would be would require a lot more engineering and financial chops than I have. Even if it is just a drop in the bucket, I think we’ll probably end up doing it, if for no other reason than it takes something like two decades to bring a new copper mine into production. Until those mines come online and drive the price of copper down, all that refined and (relatively) easily recycled copper just sitting there is a tempting target for investors. So it’ll probably happen, which is sad in a way, but maybe it’s a more fitting end to the PSTN than just letting it sit there and corrode.

Controlling an e-bike is pretty straightforward. If you want to just let it rip, it’s a no-brainer — or rather, a one-thumber, as a thumb throttle is the way to go. Or, if you’re still looking for a bit of the experience of riding a bike, sensing when the pedals are turning and giving the rider a boost with the motor is a good option.

But what if your e-conveyance is more of the aquatic variety? That’s an interface design problem of a different color, as [Braden Sunwold] has discovered with his DIY e-kayak. We’ve detailed his work on this already, but for a short recap, his goal is to create an electric assist for his inflatable kayak, to give you a boost when you need it without taking away from the experience of kayaking. To that end, he used the motor and propeller from a hydrofoil to provide the needed thrust, while puzzling through the problem of building an unobtrusive yet flexible controller for the motor.

His answer is to mount an inertial measurement unit (IMU) in a waterproof container that can clamp to the kayak paddle. The controller is battery-powered and uses an nRF link to talk to a Raspberry Pi in the kayak’s waterproof electronics box. The sensor also has an LED ring light to provide feedback to the pilot. The controller is set up to support both a manual mode, which just turns on the motor and turns the kayak into a (low) power boat, and an automatic mode, which detects when the pilot is paddling and provides a little thrust in the desired direction of travel.

The video below shows the non-trivial amount of effort [Braden] and his project partner [Jordan] put into making the waterproof enclosure for the controller. The clamp is particularly interesting, especially since it has to keep the sensor properly oriented on the paddle. [Braden] is working on a machine-learning method to analyze paddle motions to discern what the pilot is doing and where the kayak goes. Once he has that model built, it should be time to hit the water and see what this thing can do. We’re eager to see the results.

We’ve been harping a lot lately about the effort by carmakers to kill off AM radio, ostensibly because making EVs that don’t emit enough electromagnetic interference to swamp broadcast signals is a practical impossibility. In the US, push-back from lawmakers — no doubt spurred by radio industry lobbyists — has put the brakes on the move a bit, on the understandable grounds that an entire emergency communication system largely centered around AM radio has been in place for the last seven decades or so. Not so in Japan, though, as thirteen of the nation’s 47 broadcasters have voluntarily shut down their AM transmitters in what’s billed as an “impact study” by the Ministry of Internal Affairs and Communications. The request for the study actually came from the broadcasters, with one being quoted in a hearing on the matter as “hop[ing] that AM broadcasting will be promptly discontinued.” So the writing is apparently on the wall for AM radio in Japan.

There was another close call this week with our increasingly active sun, which tried but didn’t quite launch a massive stream of plasma out into space. The M-class flare was captured in the act by the Solar Dynamics Observatory, which keeps an eye on what’s going on with our star. The video of the outburst is fascinating; it almost looks like a CGI render, but it’s real imaging and pretty spectacular. The active region on the sun’s surface suddenly belches out a few gigatons of plasma, which quickly get sucked right back down to the surface. You can actually see the material following ethereal lines of magnetic force, and the way it splashes when it hits the surface is just beautiful. Seeing this puts us in the mood for a feature on the SDO and how it gets these fascinating images, so stay tuned for that.

Also in space news, we’re saddened by the sudden loss of yet another of the Apollo astronauts. Bill Anders, lunar module pilot on Apollo 8, died Friday in a small plane crash off San Juan Island in Washington. Anders, 90, was piloting the Beechcraft T-34 Mentor, a single-engine military trainer aircraft from the 1950s. Anders’ only trip in space was Apollo 8, but what a trip it was. Along with Commander Frank Borman and pilot James Lovell, they were the first humans to leave Earth’s gravity well and visit another world, riding the mighty Saturn V rocket all the way to the Moon for a ten-orbit visit that paved the way for the landing on Apollo 11. He is also officially the luckiest photographer in history, having been in just the right place at just the right time to snap the famous “Earthrise” picture that gave us for the first time a Moon’s-eye-view of our fragile little world:

Godspeed, Major General Anders.

In more mundane news, a story from Maryland that should give anyone who depends on tools for a living a moment’s pause. Police cracked a massive tool-theft ring thanks to the actions of a carpenter who, sick of having his tools ripped off repeatedly, stashed a couple of AirTags among his stock in trade. When the inevitable occurred and his tools took a walk yet again, he tracked them to a storage facility and alerted police. They in turn conducted an investigation and got search warrants for twelve locations, where the scale of this criminal enterprise became apparent. Check out the photos in the story; mountains of cordless tools sorted by brand, DeWalt yellow here and Milwaukee red there. There’s a surprising amount of puke-green Ryobi, too; are people really trying to make money with those tools? Between the piles of cordless tools and the rows of air compressors, the total value of the haul is estimated to be from $3 to $5 million. Hats off to the carpenter for running his own mini-sting operation.

And finally, from the Genuinely Interesting Apps files we have ShadeMap, which does exactly what you think it does: plot shade and shadow on a map. It has controls for time and date, and zooms down to a pretty fine level of detail, even for the free version. Shadows from buildings, terrain, and trees are calculated and displayed, making it perfect for surveys of locations for solar power installations. There’s also supposed to be a way to virtually remove shadow-casting features, although we couldn’t find it; perhaps in a paid version? That would be a handy tool indeed to see which trees need to be cut down or which buildings demolished to improve your solar aspect. YMMV on that last one, of course.

[Will Cogley] makes eyeballs; hey, everyone needs a hobby, and we don’t judge. Like all his animatronics, his eyeballs are wondrous mechanisms, but they do tend toward being a bit complex, especially in terms of the fasteners needed to assemble them.

But not anymore. [Will] redid his eyeball design to be as easy to assemble as possible, and the results are both impressive and instructive. His original design mimics real eyeballs quite well, but takes six servos and a large handful of screws and nuts, which serve both to attach the servos to the frame and act as pivots for the many, many linkages needed. The new design has snap-fit pivots similar to Lego Technic axles printed right into the linkage elements, as well as snap connectors to hold the servos down. This eliminates the need for 45 screws and cuts assembly time from 30 minutes to about six, with no tools required. And although [Will] doesn’t mention it, it must save a bunch of weight, too.

Everything comes at a cost, of course, and such huge gains in assembly ease are no exception. [Will] details this in the video below, including printing the parts in the right orientation to handle the forces exerted both during assembly and in use. And while it’s hard to beat a five-fold reduction in assembly time, he might be able to reduce that even more with a few print-in-place pivots.