Halfway Between Inspiration And Engineering

July 6, 2024 by Elliot Williams 7 Comments

We see a lot of hacks where the path to success is pretty obvious, if maybe strewn with all sorts of complications, land-mines, and time-sinks. Then we get other hacks that are just totally out-of-the-box. Maybe the work itself isn’t so impressive, or even “correct” by engineering standards, but the inner idea that’s so crazy it just might work shines through.

This week, for instance, we saw an adaptive backlight LED TV modification that no engineer would ever design. Whether it was just the easiest way out, or used up parts on hand, [Mousa] cracked the problem of assigning brightnesses to the LED backlights by taking a tiny screen, playing the same movie on it, pointing it at an array of light sensors, and driving the LEDs inside his big TV off of that. No image processing, no computation, just light hitting LDRs. It’s mad, and it involves many, many wires, but it gets the job done.

Similarly, we saw an answer to the wet-3D-filament problem that’s as simple as it could possibly be: basically a tube with heated, dry air running through it that the filament must pass through on it’s way to the hot end. We’ve seen plenty of engineered solutions to damp filament, ranging from an ounce of prevention in the form of various desiccant storage options, to a pound of cure – putting the spools in the oven to bake out. We’re sure that drying filament inline isn’t the right way to do it, but we’re glad to see it work. The idea is there when you need it.

Not that there’s anything wrong with the engineering mindset. Quite the contrary: most often taking things one reasonable step at a time, quantifying up all the unknowns, and thinking through the path of least resistance gets you to the finish line of your project faster. But we still have to admire the off-the-wall hacks, where the way that makes the most sense isn’t always the most beautiful way to go. It’s a good week on Hackaday when we get both types of projects in even doses.

Candle Powered Lantern Isn’t As Silly As You Think

July 6, 2024 by Adam Fabio 30 Comments

[Gilles Messier] at the Our Own Devices YouTube channel recently took a look at an interesting device — an electric lantern powered by a candle. At first glance, this sounds completely absurd. Why use a candle to power LEDs when you can use the light from the candle itself? This gadget has a trick up its sleeve, though. It lets candle light out and uses the heat from the candle flame to generate power for the LEDs.

The small Peltier “solid-state heat pump” module in the lantern acts as a thermoelectric generator, converting heat from the candle into electricity for the LEDs. The genius of the device is how it handles the candle “exhaust”. A bimetallic disk in the chimney of the lantern closes when the air inside the device is hot. The Peltier device converts the heat differential to electricity, causing the air inside the lantern to cool. Meanwhile, the candle is beginning to starve for oxygen. Once the air cools down a bit, the disk bends, allowing stale smoke out, and fresh air in, allowing the candle to burn brightly again. Then the cycle repeats.

[Gilles] does a deep dive into the efficiency of the lantern, which is worth the price of admission alone. These lanterns are pretty expensive — but Peltier modules are well-known by hackers. We’re sure it won’t be too hard to knock together a cheap version at home.

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New Solar Spheres Claim To Be Better Than Solar Panels

July 6, 2024 by Al Williams 83 Comments

When you think of solar energy, you probably think of flat plates on rooftops. A company called WAVJA wants you to think of spheres. The little spheres, ranging from one to four inches across, can convert light into electricity, and the company claims they have 7.5 times the output of traditional solar panels and could later produce even more. Unfortunately, the video below doesn’t have a great deal of detail to back up the claims.

Some scenes in the video are clearly forward-looking. However, the so-called photon energy system appears to be powering a variety of real devices. It’s difficult to assess some of the claims. For example, the video claims 60 times the output of a similar-sized panel. But you’d hardly expect much from a tiny 4-inch solar panel.

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Building An IR Thermometer That Fits On Your Keychain

July 5, 2024 by Tom Nardi 11 Comments

Non-contact infrared (IR) thermometers used to be something of an exotic tool, but thanks at least in part due to the COVID-19 pandemic, they’re now the sort of thing you see hanging up near the grocery store checkout as a cheap impulse buy. Demand pushed up production, and the economies of scale did the test. Now the devices, and the sensors within them, are cheap enough for us hackers to play with.

The end result is that we now have projects like this ultra compact IR thermometer from [gokux]. With just a handful of components, some code to glue it all together, and a 3D printed enclosure to wrap it all up, you’ve got a legitimately useful tool that’s small enough to replace that lucky rabbit’s foot you’ve got on your keys.

If this project looks familiar, it’s because the whole thing is closely related to the LiDAR rangefinder [gokux] put together last month. It shares the same Seeed Studio XIAO ESP32-C3 microcontroller, 0.49 inch OLED display, and tiny 40 mAh LiPo battery. The only thing that’s really changed, aside from the adjustments necessary to the 3D printed enclosure, is that the LiDAR sensor was replaced with a MLX90614 IR temperature sensor.

[gokux] has put together some great documentation for this build, making it easy for others to recreate and remix on their own. Assembly is particularly straightforward thanks to the fact that both the display and temperature sensor communicate with the ESP32 over I2C, allowing them to be wired daisy chain style — there’s no need for even a scrap of perfboard inside the case, let alone a custom board.

Dad? Where Did Printed Circuit Boards Come From?

July 5, 2024 by Al Williams 18 Comments

These days, it is hard to imagine electronics without printed circuit boards. They are literally in everything. While making PCBs at home used to be a chore, these days, you design on a computer, click a button, and they show up in the mail. But if you go back far enough, there were no PC boards. Where did they come from? That’s the question posed by [Steven Leibson] who did some investigating into the topic.

There were many false starts at building things like PCBs using wires glued to substrates or conductive inks. However, it wasn’t until World War II that mass production of PC boards became common. In particular, they were the perfect solution for proximity fuzes in artillery shells.

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The Thermite Process Iron Foundry

July 5, 2024 by Jenny List 14 Comments

The thermite process is a handy way to generate molten iron in the field. It’s the reaction between aluminium metal and iron oxide, which results in aluminium oxide and metallic iron. It’s hot enough that the iron is produced as a liquid, which means it’s most notably used for in-field welding of things such as railway tracks. All this is grist to [Cody’s Lab]’s mill of course, so in the video below the break he attempts to use a thermite reaction in a rough-and-ready foundry, to make a cast-iron frying pan.

Most of the video deals with the construction of the reaction vessel and the mold, for which he makes his own sodium silicate and cures it with carbon dioxide. The thermite mix itself comes from aluminium foil and black iron oxide sand, plus some crushed up drinks cans for good measure.

The result is pretty successful at making a respectable quantity of iron, and his pour goes well enough to make a recognizable frying pan. It has a few bubbles and a slight leak, but it’s good enough to cook an egg. We’re sure his next try will be better. Meanwhile this may produce a purer result, but it’s by no means the only way to produce molten iron on a small scale.

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A Look Back At The USSR’s Mi-6 Helicopter Airliner

July 5, 2024 by Maya Posch 26 Comments

Most of us would equate commercial airline travel with fixed-wing aircraft, but civilian transport by helicopter, especially in large and sparsely populated regions, is common enough. It was once even big business in the Soviet Union, where the Aeroflot airline operated passenger helicopters in regular service for many decades. In the mid-1960s they even started work on converting the Mil Mi-6 — the USSR’s largest and fastest helicopter — to carry paying passengers. Unfortunately this never got past a single prototype, with the circumstances described by [Oliver Parken] in a recent article.

This passenger version of the Mi-6 got the designation Mi-6P (for passazhirskyi, meaning passenger) and would have seated up to 80 (3 + 2 row configuration), compared to the Mi-8 passenger variant that carried 28 – 31 passengers. Why exactly the Mi-6P never got past the prototype stage is unknown, but its successor in the form of the Mi-26P has a listed passenger variant and features. Both have a cruising speed of around 250 km/h, with a top of 300 km/h. The auxiliary winglets of the Mi-6 provided additional lift during flight, and the weight lifting record set by the Mi-6 was only broken by the Mi-26 in 1982.

An obvious disadvantage of passenger helicopters is that they are more complicated to operate and maintain, while small fixed wing airliners like the ATR 72 (introduced in 1988) can carry about as many passengers, requires just a strip of tarmac to land and take off from, travel about twice as fast as an Mi-6P would, and do not require two helicopter pilots to fly them. Unless the ability to hover and land or take-off vertically are required, this pretty much explains why passenger helicopters are such a niche application. Not that the Mi-6P doesn’t have that certain je ne sais quoi to it, mind.