Piano Gets An Arduino Implant

February 16, 2025 by 18 Comments

[Paul] likes his piano, but he doesn’t know how to play it. The obvious answer: program an Arduino to do it. Some aluminum extrusion and solenoids later, and it was working. Well, perhaps not quite that easy — making music on a piano is more than just pushing the keys. You have to push multiple keys together and control the power behind each strike to make the music sound natural.

The project is massive since he chose to put solenoids over each key. Honestly, we might have been tempted to model ten fingers and move the solenoids around in two groups of five. True, the way it is, it can play things that would not be humanly possible, but ten solenoids, ten drivers, and two motors might have been a little easier and cheaper.

The results, however, speak for themselves. He did have one problem with the first play, though. The solenoids have a noticeable click when they actuate. The answer turned out to be orthodontic rubber bands installed on the solenoids. We aren’t sure we would have thought of that.

Player pianos, of course, are nothing new. And, yes, you can even make one with a 555. If a piano isn’t your thing, maybe try a xylophone instead.

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Scrapyard Vacuum Dehydrator Sucks The Water From Hydraulic Oil

February 16, 2025 by 23 Comments

Anyone who has ever had the misfortune of a blown head gasket knows that the old saying “oil and water don’t mix” is only partially true. When what’s coming out of the drain plug looks like a mocha latte, you know you’re about to have a very bad day.

[SpankRanch Garage] recently found himself in such a situation, and the result was this clever vacuum dehydrator, which he used to clean a huge amount of contaminated hydraulic fluid from some heavy equipment. The machine is made from a retired gas cylinder welded to a steel frame with the neck pointing down. He added a fill port to the bottom (now top) of the tank; as an aside, we had no idea the steel on those tanks was so thick. The side of the tank was drilled and threaded for things like pressure and temperature gauges as well as sight glasses to monitor the process and most importantly, a fitting for a vacuum pump. Some valves and a filter were added to the outlet, and a band heater was wrapped around the tank.

To process the contaminated oil, [Spank] glugged a bucket of forbidden milkshake into the chamber and pulled a vacuum. The low pressure lets the relatively gentle heat boil off the water without cooking the oil too badly. It took him a couple of hours to treat a 10-gallon batch, but the results were pretty stark. The treated oil looked far better than the starting material, and while it still may have some water in it, it’s probably just fine for excavator use now. The downside is that the vacuum pump oil gets contaminated with water vapor, but that’s far easier and cheaper to replace that a couple hundred gallons of hydraulic oil.

Never doubt the hacking abilities of farmers. Getting things done with what’s on hand is a big part of farm life, be it building a mower from scrap or tapping the power of the wind.

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Curious Claim Of Conversion Of Aluminium Into Transparent Aluminium Oxide

February 15, 2025 by 31 Comments

Sometimes you come across a purported scientific paper that makes you do a triple-check, just to be sure that you didn’t overlook something, as maybe the claims do make sense after all. Such is the case with a recent publication in the Langmuir journal by [Budlayan] and colleagues titled Droplet-Scale Conversion of Aluminum into Transparent Aluminum Oxide by Low-Voltage Anodization in an Electrowetting System.

Breaking down the claims made and putting them alongside the PR piece on the [Ateneo De Manila] university site, we start off with a material called ‘transparent aluminium oxide’ (TAlOx), which only brings to mind aluminium oxynitride, a material which we have covered previously. Aluminium oxynitride is a ceramic consisting of aluminium, oxygen and nitrogen that’s created in a rather elaborate process with high pressures.

In the paper, however, we are talking about a localized conversion of regular aluminium metal into ‘transparent aluminium oxide’ under the influence of the anodization process. The electrowetting element simply means overcoming the surface tension of the liquid acid and does not otherwise matter. Effectively this process would create local spots of more aluminium oxide, which is… probably good for something?

Combined with the rather suspicious artefacts in the summary image raising so many red flags that rather than the ‘cool breakthrough’ folder we’ll be filing this one under ‘spat out by ChatGPT’ instead, not unlike a certain rat-centric paper that made the rounds about a year ago.

Man using a table saw with a VR headset on

Chop, Chop, Chop: Trying Out VR For Woodworking

February 15, 2025 by 23 Comments

Virtual Reality in woodworking sounds like a recipe for disaster—or at least a few missing fingers. But [The Swedish Maker] decided to put this concept to the test, diving into a full woodworking project while wearing a Meta Quest 3. You can check out the full experiment here, but let’s break down the highs, lows, and slightly terrifying moments of this unconventional build.

The plan: complete a full furniture build while using the VR headset for everything—from sketching ideas to cutting plywood. The Meta Quest 3’s passthrough mode provided a semi-transparent AR view, allowing [The Swedish Maker] to see real-world tools while overlaying digital plans. Sounds futuristic, right? Well, the reality was more like a VR fever dream. Depth perception was off, measuring was a struggle, and working through a screen-delayed headset was nauseating at best. Yet, despite the warped visuals, the experiment uncovered some surprising advantages—like the ability to overlay PDFs in real-time without constantly running back to a computer.

So is VR useful to the future of woodworking? If you’re a woodworking novice, you might steer clear from VR and read up on the basics first. For the more seasoned: maybe, when headsets evolve beyond their current limitations. For now, it’s a hilarious, slightly terrifying experiment that might just inspire the next wave of augmented reality workshops. If you’re more into electronics, we did cover the possibilities with AR some time ago. We’re curious to know your thoughts on this development in the comments!

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You Know This Font, But You Don’t Really Know It

February 15, 2025 by 18 Comments

Typography enthusiasts reach a point at which they can recognise a font after seeing only a few letters in the wild, and usually identify its close family if not the font itself. It’s unusual then for a font to leave them completely stumped, but that’s where [Marcin Wichary] found himself. He noticed a font which many of you will also have seen, on typewriter and older terminal keys. It has a few unusual features that run contrary to normal font design such as slightly odd-shaped letters and a constant width line, and once he started looking, it appeared everywhere. Finding its origin led back well over a century, and led him to places as diverse as New York street furniture and NASA elevators.

The font in question is called Gorton, and it came from the Gorton Machine Co, a Wisconsin manufacturer. It’s a font designed for a mechanical router, which is why it appears on so much custom signage and utilitarian components such as keyboard keys. Surprisingly its history leads back into the 19th century, predating many of the much more well-know sans serif fonts. So keep an eye out for it on your retro tech, and you’ll find that you’ve seen a lot more of it than you ever knew. If you are a fellow font-head, you might also know the Hershey Font, and we just ran a piece on the magnetic check fonts last week.

Thanks [Martina] for the tip!

Octet Of ESP32s Lets You See WiFi Like Never Before

February 15, 2025 by 14 Comments

Most of us see the world in a very narrow band of the EM spectrum. Sure, there are people with a genetic quirk that extends the range a bit into the UV, but it’s a ROYGBIV world for most of us. Unless, of course, you have something like this ESP32 antenna array, which gives you an augmented reality view of the WiFi world.

According to [Jeija], “ESPARGOS” consists of an antenna array board and a controller board. The antenna array has eight ESP32-S2FH4 microcontrollers and eight 2.4 GHz WiFi patch antennas spaced a half-wavelength apart in two dimensions. The ESP32s extract channel state information (CSI) from each packet they receive, sending it on to the controller board where another ESP32 streams them over Ethernet while providing the clock and phase reference signals needed to make the phased array work. This gives you all the information you need to calculate where a signal is coming from and how strong it is, which is used to plot a sort of heat map to overlay on a webcam image of the same scene.

The results are pretty cool. Walking through the field of view of the array, [Jeija]’s smartphone shines like a lantern, with very little perceptible lag between the WiFi and the visible light images. He’s also able to demonstrate reflection off metallic surfaces, penetration through the wall from the next room, and even outdoor scenes where the array shows how different surfaces reflect the signal. There’s also a demonstration of using multiple arrays to determine angle and time delay of arrival of a signal to precisely locate a moving WiFi source. It’s a little like a reverse LORAN system, albeit indoors and at a much shorter wavelength.

There’s a lot in this video and the accompanying documentation to unpack. We haven’t even gotten to the really cool stuff like using machine learning to see around corners by measuring reflected WiFi signals. ESPARGOS looks like it could be a really valuable tool across a lot of domains, and a heck of a lot of fun to play with too.

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How To Find Where A Wire In A Cable Is Broken

February 15, 2025 by 43 Comments

Determining that a cable has a broken conductor is the easy part, but where exactly is the break? In a recent video, [Richard] over at the Learn Electronics Repair channel on YouTube gave two community-suggested methods a shake to track down a break in a proprietary charging cable. The first attempt was to run a mains power detector along the cable to find the spot, but he didn’t have much luck with that.

The second method involved using the capacitance of the wires, or specifically treating two wires in the cable as the electrodes of a capacitor. Since the broken conductor will be shorter, it will have less capacitance, with the ratio theoretically allowing for the location of the break in the wire to be determined.

In the charging cable a single conductor was busted, so its capacitance was compared from both sides of the break and compared to the capacitance of two intact conductors. The capacitance isn’t much, on the order of dozens to hundreds of picofarads, but it’s enough to make an educated guess of where the rough location is. In this particular case the break was determined to be near the proprietary plug, which ruled out a repair as the owner is a commercial rental shop of e-bikes.

To verify this capacitor method, [Richard] then did it again on a piece of mains wire with a deliberate cut to a conductor. This suggested that it’s not a super accurate technique as applied, but ‘good enough’. With a deeper understanding of the underlying physics it likely can be significantly more accurate, and it’s hardly the only way to find broken conductors, as commentators to the video rightly added.

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