2026-01-18 11:00:00
Part of any self-respecting Smart Home, smart relays are useful for switching and monitoring loads that do not plug into an outlet. This also makes them a lot more integrated, and thus, a long lifespan is very welcome. Unfortunately, the popular Shelly 2.5 smart relays seem to be having a bit of a design flaw as they’re dying in droves once their 2-year warranty period is up. The cause and repair are covered in a recent [VoltLog] video on YouTube.
As noted in the Shelly documentation for the device, it’s a very compact form factor device, with screw terminals, two relays, and three fairly large electrolytic capacitors sharing very little space with the rest of the components. The apparent flaw comes in the form of these capacitors failing, with the video showing that one 100 µF capacitor has a massively increased ESR, likely due to electrolyte venting. This results in the observed symptoms, such as WiFi connectivity issues and audible hissing, the latter of which is demonstrated in the video.
Due to the cramped space, the replacement capacitors need to be at least as small as listed in the video and in the top screenshot, though mind the typo as ‘400µF’ has to be ‘100µF’. This limitation posed a bit of a problem, as for the two 400V, 4.7 µF capacitors, there aren’t that many options in that form factor. The original capacitors are definitely B- or C-grade ones, with the two large capacitors Chongx branded, being a well-known budget capacitor brand. The other capacitor’s branding cannot be made out in the video, but is likely also Chongx or a similar, less well-regarded Chinese brand.
For the replacements, a Nippon Chemicon capacitor was picked for the 100 µF capacitor, and Ymin-branded capacitors to fit within the size limitations. Picking Ymin over a second Nippon Chemicon set or similar was due to these unfortunate sizing limitations, but these Ymin replacement capacitors had the best datasheet of the options on LCSC. All of these capacitors have to be rated for 105°C, for obvious reasons.
Although it’s not easy to say for certain what caused these capacitors to fail so quickly without more data, it seems likely that having the SMPS circuitry for the 3.3V rail bunched up cozily with the three electrolytic capacitors and what looks like two load resistors inside the cramped enclosure with no clear ventilation holes does little to help the electrolytic capacitors hit their listed MTBF hours. Hopefully, using the new capacitors, these relays will last longer than 2-3 years before another recapping is needed.
2026-01-18 08:00:59
There’s a famous book that starts: “It is a truth universally acknowledged that a man in possession of a good e-ink display, must be in want of a weather station.” — or something like that, anyway. We’re not English majors. We are, however, major fans of this feline-based e-ink weather display by [Jesse Ward-Bond]. It’s got everything: e-ink, cats, and AI.
AI? Well, it might seem a bit gratuitous for a simple weather display, but [Jesse] wanted something a little more personalized and dynamic than just icons. With that in the design brief, he turned to Google’s Nano Banana API, feeding it the forecast and a description of his cats to automatically generate a cute scene to match the day’s weather.
That turned out to not be enough variety for the old monkey brain, so the superiority of silicon — specifically Gemini–was called upon to write unique daily prompts for Nano Banana using a random style from a list presumably generated by TinyLlama running on a C64. Okay, no, [Jesse] wrote the prompt for Gemini himself. It can’t be LLM’s all the way down, after all. Gemini is also picking the foreground, background, and activity the cats will be doing for maximum neophilia.
Aside from the parts that are obviously on Google servers, this is all integrated in [Jesse]’s Home Assistant server. That server stores the generated image until the ESP32 fetches it. He’s using a reTerminal board from SeedStudio that includes an ESP32-S3 and a Spectrum6 coloor e-ink display. That display leaves something to be desired in coloration, so on top of dithering the image to match the palette of the display, he’s also got a bit of color-correction in place to make it really pop.
If you’re interested in replicating this feline forecast, [Jesse] has shared the code on GitHub, but it comes with a warning: cuteness isn’t free. That is to say, the tokens for the API calls to generate these images aren’t free; [Jesse] estimates that when the sign-up bonus is used up, it should cost about fourteen cents a pop at current rates. Worth it? That’s a personal choice. Some might prefer saving their pennies and checking the forecast on something more physical, while others might prefer the retro touch only a CRT can provide.
2026-01-18 05:00:52
Press brakes are invaluable tools when working with sheet metal, but along with their almost infinite versatility comes a dizzying number of press brake types. After starting with an old-school, purely mechanical press brake, [Wes] of Watch Wes Work fame had been thinking of upgrading said press brake to a hydraulic configuration, but soured on this after facing all the disadvantages of the chosen approach. Thus, one does what any rational person does and purchases a used and very much untested 45-ton computer-controlled hydraulic press brake.
The video first explores the pros and cons of the various types of press brakes, with the issue of providing a balanced force across the entirety of the press brake’s dies being the largest problem. Although various mechanical and hydraulic solutions were attempted over the decades, a computer-controlled press brake like this Gasparini PBS 045 that [Wes] got is probably one of the more effective solutions, even if it provides the headache of more electrical and electronic things that can go wrong. The above screenshot of its basic workings should make that quite obvious, along with [Wes]’s detailed explanation.
As it turned out, this about 25-year-old Italian press brake wasn’t in such a terrible nick, but needed some badly needed TLC and obligatory breaker testing to bring it back to life. While it doesn’t like you not centering the part, this can be worked around by specifying that the part is actually larger than it is. Although [Wes] got it working well enough to do some work with it, it still has some gremlins left in it that will hopefully be hunted down over the coming time and video(s).
2026-01-18 02:00:45
When it comes to designing a mopping robot, there are a number of approaches you can pick from, including just having the movement of the robot push the soggy mop over the floor, having spinning pads, or even a big spinning roller. But what difference does it make? Recently the [Vacuum Wars] channel ran a comparison to find out the answer.
The two spinning pad design is interesting, because it allows for the bot to move closer to objects or walls, and the base station doesn’t need the active scrubber that the simple static pad requires. The weakness of both types of flat mop design is that they are quickly saturated with dirt and moisture, after which they’ll happily smear it over the floor.
The spinning roller is the most complex, with the robot having its own onboard water tank, and a way to extract the dirty water from the mop and store it for disposal in the base station. Theoretically this would be the clear winner, with basically all of them having features like avoiding carpet.
Taking the test data from 150 different mopping robots that were made to clean up dried-up coffee stains, the results weren’t as clear-cut as one might perhaps expect due to the very limited scope of the test. But the comments to the video are perhaps more revealing. After all, most people don’t briefly run their robot mop over a few dried-up stains, but are faced with more severe real-life scenarios.
One commentator mentions their dogs dragging in a lot of mud on rainy days, in which case the spinning pads robot would end up spreading a thin film of mud across the floor. After upgrading to a spinning roller version this issue was resolved, though it’s readily admitted to be the more expensive system, with a much larger base station.
When in the video you see the details of what each approach involves on the side of the robot, the base station and the human caretaker, trade-offs are clear. Having the fixed flat pad is simple, but moves all complexity to the base station, with the spinning pads removing at least the need to motorize the base station. If you have small children or pets with muddy paws around, neither option works well, so you either have to whip out the human-powered mop or shell out for the high-end robotic solution.
Of course, you can also build your own super-charged robot mop, or a very thorough one, but definitely avoid mopping robots that are too cheap to actually work.
2026-01-17 23:00:01
My son went over to a friends house this afternoon, when my wife had been planning on helping him with his French homework. This meant she had an hour or so of unexpected free time. Momentarily at a loss, she asked me what she should do, and my reply was “slack off”, meaning do something fun and creative instead of doing housework or whatever. Take a break! She jokingly replied that slacking off wasn’t on her to-do list, so she wouldn’t even know how to start.
But as with every joke, there’s more than a kernel of truth to it. We often get so busy with stuff that we’ve got to do, that we don’t leave enough time to slack, to get bored, or to simply do nothing. And that’s a pity, because do-nothing time is often among the most creative times. It’s when your mind wanders aimlessly that you find inspiration for that upgrade to the z-stage on your laser cutter, or whatever the current back-burner project of the moment is.
You don’t get bored when you’re watching TV, playing video games, or scrolling around the interwebs on your phone, and it’s all too easy to fall into these traps. To get well and truly bored requires discipline these days, so maybe putting “slack” into your to-do list isn’t a bad idea after all. My wife was right! And that’s why I volunteered to take my son to parkour on Sundays – it’s and hour of guaranteed, 100% uninterruptible boredom. How do you make sure you get your weekly dose of slack?
2026-01-17 20:00:32
A couple of years ago, we covered a project called Arnis, created by [Louis Erbkamm], which allowed you to generate any portion of Earth into Minecraft blocks and maps. It was already impressive, but since we last checked in the open source project has made some incredible progress.
When we first covered Arnis, it was stuck on the Java edition of Minecraft. But now the project has been updated to support the more modern Bedrock Edition, meaning you can put your home into any device’s version of Minecraft!
Beyond Bedrock version support, the actual tool has improved with proper elevation generation using data provided from NASA. This allows you to view the Alps or the Himalayas in all their voxel glory, or explore an entire map of the Moon. Perhaps what’s even more impressive is that the generation is accurate enough to be used in an actual research study involving flood mitigation education.
All of this has been made possible with help from a passionate community who have volunteered their time to assist [Louis] with the project — a testament to the power of open source.
