Inside A Dutch Street Organ: The Art Of Mechanical Music-Making

February 18, 2026 by No comments

[James]’ Mechanical Organ of Dutch origin has been around longer than he has, but thanks to being rebuilt over the years and lovingly cared for, it delivers its unique performances just as well as it did back in the day. Even better, we’re treated to a good look at how it works.

The organ produces music by playing notes on embedded instruments, which are themselves operated by air pressure, with note arrangements read off what amounts to a very long punch card. [James] gives a great tour of this fantastic machine, so check it out in the video embedded below along with a couple of its performances.

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Creating The World’s Most Efficient Quadcopter Drone

February 18, 2026 by 2 Comments
Keeping an eye on remaining battery charge. (credit: Luke Maximo Bell, YouTube)
Keeping an eye on remaining battery charge. (credit: Luke Maximo Bell, YouTube)

Although not a typical focus of people who fly quadcopter drones for a hobby or living, endurance flying has a certain appeal to it for the challenge it offers. Thus, as part of his efforts to collect all the world records pertaining to quadcopter drones, [Luke Maximo Bell] has been working on a design that would allow him to beat the record set by SiFly Aviation at 3 hours and 11 minutes.

By using knowledge gained from his PV solar-powered quadcopter, [Luke] set about to take it all a few steps further. The goal was to get as much performance out of a single Watt, which requires careful balancing of weight, power output and many other parameters.

Crucial is that power usage goes up drastically when you increase the RPM of the propellers, ergo massive 40″ propellers were picked to minimize the required RPM to achieve sufficient lift, necessitating a very large, but lightweight frame.

The battery packs are another major factor since they make up so much of the weight. By picking high-density Tattu batteries and stripping these down even more this was optimized for as well, before even the wire gauge of the power wires running to the motors were investigated to not waste a single Watt or gram.

All of this seems to have paid off, as a first serious test flight resulted in a 3 hour, 31 minutes result, making it quite feasible that [Luke] will succeed with his upcoming attempt at the world’s longest flying electric multirotor record. Another ace up his sleeve here is that of forward movement as well as wind provides effectively free lift, massively reducing power usage and possibly putting the 4 hour endurance score within easy reach.

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2026 Hackaday Europe Call For Participation: We Want You!

February 18, 2026 by 2 Comments

Here’s the Hackaday Europe 2026 announcement that you’ve all been waiting for. But wait! This year there’s a twist, or rather two. What absolutely hasn’t changed, though, is that we’d love to see you there, and we’d love to hear about what you’ve been up to, so get your talk or workshop proposal in before March 18th.

New Place, New Time

Hackaday Europe is moving in all four dimensions! We’ll be meeting up in the absolutely lovely Lecco, Italy — just about equidistant from Milan and Bergamot, and taking place May 16th and 17th, with the traditional pre-event meetup on the night of the 15th for those who are already in town. The location is the Politecnico Milano campus, a hub of engineering nestled in the mountains.

Who is going to be speaking at Hackaday Europe? You could be! We’re opening up the Call for Participation right now, both for talks and for workshops. Whether you’ve presented your work live before or not, you’re not likely to find a more appreciative audience for epic hacks, creative constructions, or you own tales of hardware, firmware, or software derring-do.

Workshop space is limited, but if you want to teach a group of ten or so people your favorite techniques, we’d love to hear from you.

All presenters get in free, of course, so firm up what you’d like to share, and get your proposal submitted ASAP.

The Badge

We’ll be bringing the 2025 Hackaday Supercon Communicator Badge with us to Europe, so this is also your chance to get your hands on the retro-styled super sexy keyboard, LoRa module, and fantastically oblong screen. At Supercon, we ran our own custom mesh network, and it worked flawlessly, even on microwatts. We’ll be continuing the experiment in Italy, on different frequencies of course, but maybe pushing some of the transmission parameters to see how far we can go.

The user side of the badge is very accessible as well, being programmed in Micropython and supported with a sweet plug-in architecture that makes adding your own apps a breeze, or at least reasonably straightforward. And when Hackaday Europe comes to a close, you can simply reflash the badge with new firmware, and you’ve got the sweetest Meshtastic device out there.

And it wouldn’t be a Hackaday badge if it weren’t meant to be modified.

The People

The real reason to come to Hackaday Europe, though, is the other folks who come to Hackaday Europe. You’ve never seen a more interested group of hardware hackers, and that’s coincidentally also why you’d like to give a presentation. You get to tell everyone what you’re up to — it’s the ultimate ice-breaker.

At the risk of saying it again: Get your proposal in before March 18th, and we look forward to seeing you on the shore of Lake Como. (Info on tickets and more pre-conference hype coming soon.)

Sliderule Simulator Teaches You How To Do Calculations The Old Fashioned Way

February 18, 2026 by 6 Comments

Ever wanted to know how engineers made their calculations before digital calculators were on every workbench? [Richard Carpenter] and [Robert Wolf] have just the thing—a sliderule simulator that can teach you how to do a whole bunch of complex calculations the old fashioned way!

The simulator is a digital recreation of the Hemmi/Post 1460 Versalog slide rule. This was a particularly capable tool that was sold from 1951 to 1975 and is widely regarded as one of the best slide rules ever made. It can do all kinds of useful calculations for you just by sliding the scales and the cursor appropriately, from square roots to trigonometry to exponents and even multi-stage multiplication and divisions.

You can try the simulator yourself in a full-screen window here. It’s written in JavaScript and runs entirely in the browser. If you’ve never used a slide rule before, you might be lost as you drag the center slide and cursor around. Fear not, though. The simulator actually shows you how to use it. You can tap in an equation, and the simulator will both spit out a list of instructions to perform the calculation and animate it on the slide rule itself. There are even a list of “lessons” and “tests” that will teach you how to use the device and see if you’ve got the techniques down pat. It’s the sort of educational tool that would have been a great boon to budding engineers in the mid-20th century. With that said, most of them managed to figure it out with the paper manuals on their own, anyway.

We’ve featured other guides on how to use this beautiful, if archaic calculation technology, too. We love to see this sort of thing, so don’t hesitate to notify the tipsline if you’ve found a way to bring the slide rule back to relevance in the modern era!

Thanks to [Stephen Walters] for the tip!

The Dismal Repairability Of Milwaukee Tools

February 18, 2026 by 36 Comments

Despite the best efforts of the manufacturers, there are folks out there that try to repair power tools, with [Dean Doherty] being one of them. Recently he got a Milwaukee M18 cordless planer in for repairs, which started off with just replacing some dodgy bearings, but ended up with diagnosing a faulty controller. Consequently the total repair costs went up from reasonable to absolutely unreasonable, leading to a rant on why Milwaukee tools are terrible to repair.

Among the symptoms was the deep-discharged battery, which had just a hair over 7 V while unloaded. Question was what had drained the battery so severely. What was clear was that the tool was completely seized after inserting a working battery with just a sad high-pitched whine from a stalled motor.

After replacing both bearings and grumbling about cheap bearings, the tool had a lot of drywall dust cleaned out and was reassembled for a test run. This sadly showed that the controller board had been destroyed due to the seized rotor bearing, explaining the drained battery. Replacing the controller would have cost €60-70 as it comes with the entire handle assembly, rendering the repair non-viable and a waste.

Perhaps the one lesson from this story is that you may as well preventively swap the cheap bearings in your Milwaukee tools, to prevent seizing and taking out the controller board. That said, we’d love to see an autopsy on this controller board fault.

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Ancient Ice Production

February 18, 2026 by 23 Comments

Today, we take ice for granted. But having ice produced in your home is a relatively modern luxury. As early as 1750 BC, ancient people would find ice on mountains or in cold areas and would harvest it. They’d store it, often underground, with as much insulation as they could produce given their level of technology.

A yakhchāls in Yazd province (by [Pastaitkaen] CC BY-SA 3.0).
By 500 BC, people around Egypt and what is now India would place water in porous clay pots on beds of straw when the night was cold and dry. Even if the temperature didn’t freeze, the combination of evaporation and radiative cooling could produce some ice. However, this was elevated to a high art form around 400 BC by the Persians, who clearly had a better understanding of physics and thermodynamics than you’d think.

The key to Persian icemaking was yakhchāls. Not all of them were the same, but they typically consisted of an underground pit with a conical chimney structure. In addition, they often had shade walls and ice pits as well as access to a water supply.

Solar Chimney

The conical shape optimizes the solar chimney effect, where the sun heats air, which then rises. The top was typically not open, although there is some thought that translucent marble may have plugged the top to admit light while blocking airflow. yakhchālThe solar chimney produces an updraft that tends to cool the interior. The underground portion of the yakhchāl has colder air, as any hot air rises above the surface.

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An Open Source Client For World Of Warcraft

February 18, 2026 by 5 Comments

When World of Warcraft was launched in 2004, it became somewhat of a juggernaut in the MMORPG space. Millions of players continue to login every month. [Kelsi Davis] is one such player, but she doesn’t always log in with the regular client anymore. That’s because she put together WoWee—an open-source alternative of her very own.

WoWee is an acronym—World of Warcraft Engine Experiment. Coded in native C++, it’s a homebrewed client that uses a custom OpenGL renderer to display the game world. [Kelsi] notes that it’s strictly an “educational/research” project, built without using any official Blizzard assets, data or code. Instead, it grabs some client data from a legally-obtained install to operate and loads certain assets this way.

It’s currently compatible with the vanilla game as well as The Burning Crusade and Wrath of the Lich King expansions. It should be highlighted how much work this project has already involved—with [Kelsi] needing to recreate various functional minutae in the game, from character creation screens to weather systems and skyboxes. There’s still a lot to do, as well, like adding 3D audio support and making it more interoperable with the quest system.

It’s rare that any MMO gets an open-source client, even less so while the original game is still being actively supported by the developers. Still, we do see some creative hacks in this space.

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