2026-03-12 04:00:18
Cycloidal drives are a type of speed reducer that are significantly more compact than gearboxes, but they still come with a fair number of components. In comparison, the harmonic pin-ring drive that [Raph] recently came across as used in some TQ electric bicycles manages to significantly reduce the number of parts to just two discs. Naturally he had to 3D model his own version for printing a physical model to play with.
How exactly this pin-ring cycloidal drive works is explained well in the referenced [Pinkbike] article. Traditional cycloidal drives use load pins that help deal with the rather wobbly rotation from the eccentric input, but this makes for bulkier package that’s harder to shrink down. The change here is that the input force is transferred via two teethed discs that are 180° out of sync, thus not only cancelling out the wobble, but also being much more compact.
It appears to be a kind of strain wave gearing, which was first patented in 1957 by C.W. Musser and became famous under the Harmonic Drive name, seeing use by NASA in the Lunar Rover and beyond. Although not new technology by any means, having it get some more well-deserved attention is always worth it. If you want to play with the 3D model yourself, files are available both on GitHub and on MakerWorld.
2026-03-12 02:30:23
There was an ideal of convergence, a long time ago, when one device would be all you need, digitally speaking. [ETA Prime] on YouTube seems to think we’ve reached that point, and his recent video about the Samsung S26 Ultra makes a good case for it. Part of that is software: Samsung’s DeX is a huge enabler for this use case. Part of that his hardware: the S26 Ultra, as the upcoming latest-and-greatest flagship phone, has absurd stats and a price tag to match.
First, it’s got 12 GB of that unobtanium once called “RAM”. It’s got an 8-core ARM processor in its Snapdragon Elite SOC, with the two performance cores clocked at 4.74 GHz — which isn’t a world record, but it’s pretty snappy. The other six cores aren’t just doddling along at 3.62 GHz. Except for the very youngest of our readers, you probably remember a time when the world’s greatest supercomputers had as much computing power as this phone.
So it should be no suprise that when [ETA Prime] plugs it into a monitor (using USB-C, natch) he’s able to do all the usual computational tasks without trouble. A big part of that is the desktop mode Samsung phones have had for a while now; we’ve seen hackers make use of it in years gone by. It’s still Android, but Android with a desktop-and-windows interface.
What are the hard tasks? Well, there’s photo and video editing, which the hardware can handle. Though [ETA] notes that it’s held back a bit because Adobe doesn’t offer their full suite on Android. But what’s really taxing for most of us is gaming. Android gaming? Well, obviously a flagship phone can handle anything in the play store.
It’s PC gaming that’s pretty impressive, considering the daisy chain of compatibility needed last time we looked at gaming on ARM. Cyberpunk 2077 gets frame rates near 60, but he needs to drop down to “low” graphics and 720p to do it. You may find that ample, or you may find it unplayable; there’s really no accounting for taste.
We might not always like carrying an everything device with us at all times, but there’s something to be said in not duplicating that functionality on your desk. Give it a couple of years when these things hit the used market at decent prices, and unless PC parts drop in price, convergence might start to seem like a great idea to those of us who aren’t big gamers and don’t need floppy drives.
2026-03-12 00:30:01
There’s a meme which may have a basis in truth, of a teenager left clueless when presented with a rotary telephone. The dial, in reality a mechanical pulse chain generator, was once ubiquitous enough that having one in your parts bin was anything but unusual. If you’re curious about their inner workings in 2026 though, you may be out of luck. Never fear though, because [Moeya 3D Designs] is here with a fully 3D printed version. It’s not as compact as the original, but it’s all there.
If you’re not put off by the anime-style Japanese voice over on the video below the break and you can enable subtitles for your language, you get the full explanation. There’s a ratchet and spring on the dial, which when released drives a gear train that ends in a cam that would operate a switch for the pulses. Another set of gears drives a very neatly designed centrifugal speed governor, and we see the effect immediately when it is removed. We’re not sure who will go for this project, but we surely like it.
There are two videos below the break, with the dial shown off in the first and the design process in the second. Meanwhile we’ve talked in the past about the networks behind the dials.
Thanks [Jan] for the tip.
2026-03-11 23:31:02
Sunday night, around 7:00 PM local time, a bright fireball streaked across the western German sky, exploded, and rained chunks of space rock down on the region around Koblenz. One of the largest known chunks put a soccer-ball-sized hole in someone’s roof, landing in their bedroom. Fortunately, nobody was hurt. But given the apparent size of the explosion, there must be many more pieces out there for the finding, and a wave of hopeful meteorite hunters has descended upon the region.
But if you wanted a piece of the action, where exactly would you start looking? How do scientists find meteorites anyway? And what should you do if you happen to see a similar fireball in the night sky?
In the age of always-on dashboard cameras, ubiquitous smartphones, and other video recording devices, it’s hard for a shy meteorite to find a quiet spot out of the public eye. That makes them a lot easier to find than they were in the past. Indeed, the International Meteor Organization, which aggregates amateur meteor observations, received more than 3,200 reports of this one, including several with video documentation. Some are stunning, and others may not even be of the event at all.
By collecting reports from many locations, they can hope to piece together the meteorite’s trajectory. However, if you look at the individual reports, it’s clear that this is a difficult task. Nobody is expecting a bright fireball to streak across the night sky, so many of the reports are reasonably vague on the details and heavy on the awe.
This report from [Sophie Z], for instance, is typical. She records where she was and roughly the location in the night sky where the meteorite passed, along with the comment “I’ve never seen anything so amazing and large before in my life.” Other amateur observers are more precise. [David C] (“I have a Ph.D in physics”) managed to record the start and the end heading of the meteorite to a couple of decimal places. He must have had a camera.
We’d love to know the exact algorithm used for combining the reports. It’s worth noting that reporters get an experience score, and the system presumably takes this into account when producing the average track. However, the system works, though, with 3,200 reports of a once-in-a-lifetime meteorite, it’s bound to come up with a pretty good estimate. But for smaller meteorites, like this one that flew by on Monday night, there are fewer observers, and deducing the actual track is a lot more difficult.
Everyday meteorites are better tracked by taking a more systematic approach. We’ve covered a few of these networks before, because the equipment needed to contribute meaningfully isn’t all that much more complicated than a single-board computer with a network connection, a camera module, and a weatherproof housing to keep it working all year round. We’ve covered the French meteorite-hunting network, Fripon, before, and have featured other amateur sky-camera builds to boot. But we’re not amateur astronomers, so we’re not in the loop on what the current state of the art is. If you know about coordinated citizen-science meteorite tracking efforts, let us know in the comments.
This meteorite was big enough and loud enough when it exploded that participation in tracking wasn’t limited to those who are looking up. Geologists at the Karlsruhe Institute for Technology (KIT) found that the explosion registered on their seismometers. (Via Heise Online.) These have the advantage that they are in very well-known locations with extremely precise timestamps. After all, that’s what they’re used for every day, although the medium that the pressure waves travel through is usually the earth rather than the air.
This was also a particularly lucky event for the KIT team because it happened over a particularly dense network of seismological stations in the Eifel mountains, allowing for greater resolution. And as they point out, using the sound of the explosion has the additional advantage of not being hindered by light conditions during the day or clouds at night. This makes us think of how easy it would be to set up a distributed system of microphones to do something similar.
The KIT track estimate lines up fairly well with the aggregated estimate from amateur observers, but it’s not exactly the same. Who is right? We’ll see where more of the meteorites are found on the ground, presumably, in the next few weeks.
If the meteorite fell through our roof and chunks were scattered all around our bedroom, we’d count ourselves lucky. But would we get to keep it? Of course, it depends on the local laws, and in Germany, you can keep the meteorites in most cases, unless the state decides that it’s of special value for whatever reason, and then they get first dibs.
Apparently, the going rate for meteorites is between 1€ and 5,000€ per gram, so we’re not entirely sure that it will cover the damage. Maybe our homeowners’ insurance would? We’ll have to go dig out our policy to be sure, but however that plays out, we’d just be stoked to have the meteorite chunks and a good story.
While very big fireballs like this are rare, NASA estimates that around 44,000 kg of meteoritic material falls on the Earth every day. (Whoah!) Most of this burns up in the atmosphere, but some falls to the ground. Most of that fraction is in the form of micrometeorites, which are sand-grain-sized bits that are very likely raining down on us every day. Indeed, if you’re interested, you can try to collect them, and all you need is a tarp on the roof or a magnet in your downspout, a good microscope, and a bit of knowledge. So if all you want is some extraterrestrial rock, and you’re not worried so much about the size, maybe micrometeorite hunting is the path to success.
Have you gone looking for meteorites? Know of any up-to-date amateur fireball-hunting networks? Sound off in the comments!
2026-03-11 19:00:08
Most people love arcade games, but putting a full-sized arcade cabinet in the living room can lead to certain unpleasant complications. Ergo the market for fun-sized cabinets has exploded alongside the availability of cheap SBCs and MCUs that can run classical arcade titles. Microcontrollers like the ESP32 with its dual 240 MHz cores can run circles around the CPU grunt of 1980s arcade hardware. Cue [Till Harbaum]’s Galagino ESP32-based arcade emulator project, that recently saw some community versions and cabinet takes.
There was a port to the PlatformIO framework by [speckhoiler] which also added a few more arcade titles and repurposed the enclosure of an off-the-shelf ‘My Arcade’ by stuffing in an ESP32-based ‘Cheap Yellow Display‘ (CYD) board instead. These boards include the ESP32 module, a touch display, micro SD card slot, sound output, and more; making it an interesting all-in-one solution for this purpose.
Most recently [Davide Gatti] and friends ported the Galagino software to the Arduino platform and added a 3D printed enclosure, though you will still need to source a stack of parts which are listed in the bill of materials. What you do get is a top display that displays the current game title in addition to the display of the usual CYD core, along with an enclosure that can be printed both in single- or multi-color.
There’s also a build video that [Davide Gatti] made, but it’s only in Italian, so a bit of a crash course in this language may be required for some finer details.
Thanks to [ZT] for the tip.
2026-03-11 16:00:38
E-readers are an awesome creation allowing you to display digital information in a way that requires little battery life. While there’s plenty of very impressive models to chose from on the commercial market, it’s also possible to build one yourself — which is exactly what [kaos-69] did in his Mimisbrunnur project, creating a truly unique e-reader from scratch.
While looking through old junk at home, [kaos-69] came across a case that held a calculator and pen at one point in the distant past. The pen was gone and the calculator no longer functioned but the case held promise. He removed the calculator and got some parts on order. For the e-paper display he went with a 5.83-inch unit that just fit inside the spring-loaded case. The Mimisbrunnur is powered by a 2000 mAh LiPo battery, with a micro SD card reader for storing what will be displayed. The brains come from an RP2040 microcontroller on an Adafruit Feather breakout board, which worked out great as it already takes care of battery management and the 24-pin interface for the e-paper display.
There are also eight buttons that live below the display for user interface, and even some LEDs to aid in reading in the dark. The depth of the case allowed all this to be connected with the use of a perfboard and some risers to set the screen forward, allowing the battery to live behind it. Using the Mimisbrunnur is pretty straightforward with the eight buttons sitting below icons on the screen giving you clear guidance on how to turn the page, add a bookmark, or browse the SD card for another file to open.
We’ve seen some impressive DIY e-readers over the years, such as the dual-screen Diptyx and the Open Book. But this project is an excellent reminder that a device doesn’t have to be complex to get the job done.
