2026-02-25 14:00:39
There are some clocks, mostly in or around international airports, which have multiple faces to show the time at various cities around the world. Taking more a forward-looking approach is [Chronova Engineering], who built a clock to display the time on four different planets: Earth, Mars, Jupiter, and Saturn.
The clock doesn’t have any hands, but it uses rotating dials to represent a top-down view of each planet from it’s north pole. The dials have degree markings to represent rotation relative to each planet’s prime meridian; for the gas giants, rotation is measured by the rotation of the planet’s core. Each dial’s center is made out of a circular stone tile with patterns similar to those seen on the planet; Earth, for example, is represented with sodalite. Three pointers mounted around the dial indicate the longitudes which are currently experiencing sunrise, noon, and sunset. The mechanism can be turned with a handle or a knob, and a mechanical counter keeps track of the number of Earth days that have passed.
[Chronova] machined most of the mechanism out of brass, with a few steel parts. It required only nine gears, including the two idler gears which were used to space out the dials and keep them rotating in the right direction. The gears were machined on a jeweler’s lathe, with the cutouts in the idler gears being made with a pantograph milling machine and a 3D printed pattern. This isn’t technically a clock, since there’s no timekeeping mechanism, but it does accurately represent relative motion.
Though they represent different things, this project is reminiscent of an orrery, which [Chronova Engineering] has previously built. For more detail about the difficulties of synchronizing time between celestial bodies, check out this article about establishing a lunar time standard.
2026-02-25 11:00:34
While you may have never heard of TAT-8, there is a good chance you sent some data through it. TAT-8 was the 8th transatlantic communications cable and the first transatlantic fiber-optic cable, carrying 560 Mbit/s on two fibers between Tuckerton, New Jersey, and, thanks to an underwater splitting device, Widemouth Bay, England, and Penmarch, France. Construction of the cable began in 1998. Later that year, the first call, made by [Issac Asimov] took place. The cable was retired in 2002. Now, Subsea Environmental Services is recovering the cable for recycling.
The 6,000 km cable was built by a consortium of companies including AT&T, France Télécom, and British Telecom. The 1.3 micron fiber used special optical repeaters about 40 km apart and cost about $335 million (just shy of a billion dollars today). Designers were optimistic, with some claiming the cable would end the need for future cables or, at least, that the cable would not reach capacity for ten years or more. In reality, the cable was saturated within 18 months. Turns out, the equivalent of 40,000 phone lines wasn’t enough.
In all fairness, the saturation might have been difficult to predict, but it may also have been hastened by the cable itself. In 1989, IBM funded a dedicated T1 link between CERN and Cornell University. Ten months later, [Tim Berners Lee] would use this link to demonstrate his new development: The World Wide Web.
According to Subsea Environmental Services, the cable still looked new after lying on the seabed for four decades. We’ve looked at the tech behind these undersea cables before. Not to mention the history behind the TAT cables.
2026-02-25 08:00:22
BMX bikes are a unique frame geometry, essentially forgoing all travel efficiency for maneuverability and sturdiness. For how much abuse these bikes are designed to take, these are all good tradeoffs. But it turns out that these bikes also have an exceptionally low center of gravity, which could make them useful for drag racing, provided they’re given a suitably large electric motor and a few minor frame modifications.
The project began as a fun weekend project for friends [Sam Barker] and [Tom Stanton]. They had a 20″ BMX wheel with a massive integrated hub motor that seemed to be begging to be put onto a BMX bike that they had on hand. After hooking up a 72V, 20Ah battery to it they were quickly zipping around the driveway, but the short wheelbase on the bike was bottlenecking its maximum performace because the bike would wheelie under high throttle. To solve that, they broke out the welder and extended frame, which kept the wheelies to a minimum and allowed them to take it out and drag race.
Another benefit to the extended frame is that the bike has room to store its battery now as well; before the frame extension it was strapped to the side of the frame under the rider in a non-ergonomic fashion. The duo also had to figure out a braking solution since the BMX didn’t come with its own brakes, but a loaner caliper from a penny farthing was found for some basic stopping abilities. We might assume this bike is not street legal on many public roads, but not every ebike operates in the same legal jurisdictions you might be the most familiar with.
2026-02-25 05:00:44
If you know about Peltier modules, a solid-state fridge seems like an easy project. Pump 12V into the module, include a heat sink and a fan. Then you are done, right? According to [Peltier Power], this is not the way to design things, but it is common enough to give these units a reputation for failing quickly.
The problem is that while it makes sense that an inefficient Peltier module needs more power to get more cooling. But the reality is in practical applications, many designs push the current up when it should be moving it down. The curve describes a parabola, and you can be on the high side or low side and still get the same result. But obviously, you don’t want to put in more current and get the same cooling that you could get with lower currents.
According to the video, the mistake people make is pushing to a stable point to reach a cool point, then increasing the current until the chamber cools further. However, maintaining the cool doesn’t have to require a higher current. Once cold, you can reduce the current to maintain temperature, so to get colder, you can just lower the current less instead of increasing it. Of course, that’s somewhat of a simplification. You have to account for other thermal design factors, but that’s the general idea.
He has noted this behavior in commercial units, but did find one brand that had the correct logic. He also has some tips on using these types of coolers.
Our favorite use for these modules has to be a cloud chamber. Naturally, we’ve seen a fair number of homebrew fridges.
2026-02-25 03:30:32
Analog TV may have shuffled off its mortal coil years ago, but there are still plenty of old CRT TV sets around that could receive it. [Kris Slyka] has just such a device, and decided to feed it something from an STM32 microcontroller. An STM32G431, to be precise, and he’s doing it using the on-chip hardware rather than in software.
This unexpected feat is made possible by clever use of the internal oscillators and analog multiplexer. The video itself is generated using the MCU’s DAC, and fed into the on-board op-amp multiplexer which is switched at the VHF transmission frequency. This creates the required VHF TV transmission, but without audio. This component comes by abusing another peripheral, the internal RC oscillator for the USB. This is frequency modulated, and set to the required 5.5 MHz spacing from the vision carrier for the TV in question. It doesn’t (yet) generate the PAL color sub-carrier so for now it’s black and white only, but maybe someone will figure out a way.
We like unexpected out-of-spec uses of parts like these microcontrollers, and we especially like analog TV hereabouts. We marked its very final moments, back in 2021.
2026-02-25 02:00:41
Personally, I love a monoblock or uni-body split. You’ll pry this Kinesis Advantage from under my cold, dead hands. But on the go, I really like the Glove 80, a true split that can be completely wireless in case you want to put the halves really far apart.
The name means to take out food, and if you click the picture you can see a cute little take-out container on the silkscreen of the right half. Directly below it, there’s a track point nubbin to be used with the thumb.
It does its split-in-half trick via a magnetic four-pin connector for when you want the halves stuck together. When the halves are separated, they can instead talk over a USB-C cable. One half has the microcontroller, and the other has a GPIO expander.
Personally, I like to push my Kinesis out of the way all the time to write by hand in a spiral notebook, and I fully appreciate that the halves stay the same distance apart. And when I’m using the Glove80 at the library, I tend to set it and forget it because I’m not there that long. But I can totally see the opposite view in both cases.
Just, wow. The gentle curve, the thumb cluster, the batarang-esque visual appeal. This is Calidris, the latest from [scytile], who brought us Cygnus a while back. I evidently didn’t cover it; shame on me.
And while some begged for Choc support for Cygnus, [scytile] decided to keep it MX-based, and so here we are with a new build that explores low-profile switches.
Calidris is columnar, hot-swappable, 36-key wireless split with a whisper of concavity. If it’s not obvious, this baby is designed for Chocs. I absolutely love the way this looks, though sadly there aren’t enough keys for me personally.
The case is so, so tiny, yet [scytile] fit a 380 mAh battery in there. Files are pending some experimentation with switch spacing, and [scytile] welcomes your (constructive) thoughts.
I must tell you that I absolutely dislike most shades of red — the color usually just makes me angry, hungry, or both. And though I prefer caramel apples, there’s something deliciously candy-apple about this red, coupled with the curves, that I just adore. I especially like the shape of it beneath Control, Z, and X. It’s like something you’d find at a futon store in the 80s.
Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!
The astute among you will notice that this typewriter clearly says Smith-Premier. But you see, not all Smith-Premiers were created alike. Buckner Lino-Typewriters were simply modified Smith-Premiers. They had keyboards with the separate upper and lower case keyboards, and they were separated vertically instead of horizontally.
There was an additional Space bar on the left side of the keyboard, and the whole idea was to mimic the layout of a Linotype press, and ease the transition to typewriters for Linotype operators, so they didn’t necessarily need to learn QWERTY.
The Buckner was loosely invented, as Antikey Chop puts it, by former Linotype press operator Homer Guy Hays Buckner. He lived in Oakland, California and started the Buckner Lino-Writer Company out of his house, which now has a freeway running through the yard.
The assumption is that Buckner basically ran a mail-order business, and just had Smith-Premier produce modified machines whenever he got an order. That’s actually kind of genius. Maybe making such connections was simpler back then.
The Antikey Chop believes that Smith-Premier Nos. 1, 2, 4, and 10 were all modified to be Buckner Lino-Typewriters, and says there may have been others. Interestingly, some No.1 models were made with their Space bars removed, and replaced with an attractive, do-nothing strip of wood. So you were forced to use the floating Space bar on left, which was admittedly a little less floaty on the wood-strip model.
But that’s not the only way Smith-Premiers were disguised as other machines. Homer Buckner sold half of his mail order business in late 1919, and by 1921, a company out of Buffalo, New York started advertising its Linowriter, which by all accounts seems to be a successor to the Buckner. The main difference was the lack of side Space bar. The Antikey Chop says that all Linowriters were modified Smith-Premier No. 10s no matter what label they bore: Smith-Premier, Linowriter, or even Remington. Good for Smith, I say.
And that someone is Keychron. This thing’s not going anywhere on your desk. There’s also a resin version of the same keyboard, which is called the K2HE Special Edition.
It looks so… plain? Which isn’t a bad thing. The nice, cuppy key caps do stand out to me. Of course, I chose the non-color picture because of the concrete blocks, but you’re not missing much. In fact, this picture shows off the cuppiness of those key caps much better than the color one, which you can see at the first link up there.
Keychron says it is smooth and marble-like, which I’m on the fence about unless it’s also polished. I don’t abide chalky textures, and I’m worried that this is very much that.
Keychron goes on to say that “each keystroke carries industrial rhythm”, which sounds like collab between Al Jourgensen and Bernard “Pretty” Purdie, or perhaps Trent Reznor and Jeff Porcaro. In other words, it sounds intriguing to say the least.
It should be noted that the chassis isn’t entirely concrete. There’s a metal panel visible in the side view where the connections are, and the back plate is sadly, plastic, at least according to PC Gamer’s inspection. But the chalkiness would not extend to the key caps, which are double-shot PBT — arguably the finest type of key caps money can buy. They are of course sitting on hot-swappable switches. You can connect via 2.4 GHz or Bluetooth, so it’ll be yet another thing to charge, but hey, concrete keyboard.
Got a hot tip that has like, anything to do with keyboards? Help me out by sending in a link or two. Don’t want all the Hackaday scribes to see it? Feel free to email me directly.
