Large Tip Driven Copter Turns Very Slowly

Picking propeller size for any aircraft, but especially VTOLs, it’s a tradeoff between size and RPM. You can either move a large volume of air slowly or a small volume of air quickly. Small and fast tend to be the most practical for many applications, but if you’re thinking outside the box like [amazingdiyprojects], you can build a massive propeller and make it fly at just one revolution per second. (Video, embedded below the break.)

One of the challenges of large propellers is their high torque requirements. To get around this, [amazingdiyprojects] drives the 5m diameter propeller from the tips using electric motors with propellers. The blades are simple welded aluminum frames covered with heat-shrunk packing tape, braced with wires for stiffness.

The flight controller, with its own battery, is prevented from spinning with the blades by counteracting the spin of a small DC motor. Each blade is equipped with a servo-driven control surface, which can give roll and pitch control by adjusting deflection based on the blade’s radial position.

[amazingdiyprojects] control setup is very creative but somewhat imprecise. Instead of trying to write a custom control scheme, he configured the old KK2.15HC flight controller for a hexacopter. Each control servo’s PWM signal routes through a commutator disc with six sectors, one for each motor of the virtual hexacopter. This means each of the servos switches between six different PWM channels throughout its rotation. To compensate for lag when switching between channels, [amazingdiyprojects] had to tune the offset of the commutator disc otherwise it would veer off in the wrong direction. After a second test flight session to tune the flight controller settings, control authority improved, although it is still very docile in terms of response.

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Replace An AA Battery With Paper

Paper is an ubiquitous part of society; so much so that the incredible engineering behind it often goes unnoticed. That isn’t the case for [Robert], though, who has a deep appreciation for the material and all its many uses far beyond recording information. In this particular video, he recreates a method found by researchers to turn a piece of paper into a battery with equivalent performance to a AA-sized alkaline battery. (Video, embedded below the break.)

The process involves the creation of a few different types of ink, each of which can be made with relatively common materials such as shellac, ethanol, polyethylene glycol, and graphite. Each of these materials are mixed in different proportions to create the inks. Once the cathode ink and anode ink are made, a third ink is needed called a current collector ink which functions essentially as a wire. The paper is dipped into a salt solution and then allowed to dry, given a partial waterproof coating, and when it is needed it can be activated by wetting it which allows the ion flow of the battery to happen.

The chemistry of this battery makes a lot of sense once you see it in action, and the battery production method also has a perk of having a long shelf life as long as the batteries stay dry. They also don’t damage the environment as much as non-rechargable alkaline cells do, at least unless you want to go to some extreme measures to reuse them.

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The Car Of Theseus Boldly Goes Where Many Cars Have Gone Before

We could all use a good chuckle every once in a while. [William Osman] revisited the ship of Theseus in a simplified manner. How many parts can you remove from a car and still be a car? (Video, embedded below the break.)

Of course, there are legal definitions of what a car is and a minimum set of requirements to be met to drive on the road. So, with two older cars ready for hacking and a group of hackers gathered, they split into two teams and started ripping parts of the vehicle. It becomes pretty humorous as it reminds us of many refactoring projects we’ve undertaken. For example, you move one BGA chip, and suddenly, it might be faster to reroute the whole board. Or you remove one component, you have to rip it out of three other modules, which affect four or more other modules, and so on. Accidentally cutting part of the electrical harness meant that one team had to dig further and further into the car to get back to a working car state. It was a race to get back to street legal while taking off more parts.

By the end of the exercise, they have a technically street-legal car they drove around, enjoying passersby’s pointed looks and confusion. They even take it to a dealership to see how much they could get for it. [William] points out that their abysmally low offer proves that a car with less stuff costs less. While we doubt that car manufacturers will follow his lead, it’s a good 15 minutes of fun.

We’ve got you covered if you’re interested in more minimal motoring.

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The SDWire board plugged into some SoM's breakout board's MicroSD socket

Automated MicroSD Card Swapping Helps In Embedded Shenanigans

[Saulius Lukse] has been working on some single board computer, seemingly, running Linux. Naturally, that boots from a microSD card – and as development goes on, that card has to be reimaged all the time. Sick of constantly plugging and unplugging the microSD card between the SBC and an SD card reader, [Saulius] started looking for a more automated solution – and it wasn’t long before he found out about the SDWire project, a hardware tool that lets you swap a card between a DUT (Device Under Test) and your personal computer with no moving parts involved.

SDWire is an offshoot from the Tizen project, evidently, designed to be of help in device development, be it single-board computers or smartphones. The idea is simple – you plug your MicroSD card into the SDWire board, plug the SDWire into a MicroSD slot of your embedded device, and then connect a USB cable from the SDWire to your development computer. This way, if you need to reflash the firmware on the SBC you’re tinkering with, you only need to issue a command to the SDWire board over the USB cable, and the MicroSD card appears as a storage drive on your computer. SDWire is a fully open source project, both in hardware and in software, and you can also buy preassembled boards online.

Such shortening of development time helps in things like automated testing, but it also speeds your development up quite a bit, saving you time between iterations, freeing you from all the tiny SD card fiddling, and letting you have more fun as you hack. There’s a clear need for a project like SDWire, as we’ve already seen a hacker assemble such a device using breakouts.

Load Your Icebreakers, The 2022 Cyberdeck Contest Starts Now

TL;DR: Enter the 2022 Cyberdeck Contest, starting right now!

When William Gibson first described the “cyberspace deck” used by the protagonists in Burning Chrome and Neuromancer, he offered only a few concrete details: they allow the user to explore cyberspace, are generally portable, and more adept owners often modify them to fit their particular needs. Anything else was left to the individual’s imagination, due in no small part to the fact that he author himself didn’t exactly know what the things would look like at the time. Still, not bad for a guy who was hammering it all out on a typewriter at the time.

Build your deck like Gibson is watching, because he is.

Now 40 years later, fact has caught up with fiction. The hacker and maker community have embraced the cyberdeck idea in a big way, and we’ve been blown away by the incredible creativity that goes into these bespoke computing devices.

Which is why we’re happy to announce the first, but very likely not the last, 2022 Cyberdeck Contest. Impress the judges with your Sprawl-ready rig, and you could claim one of three $150 USD Digi-Key shopping sprees to help fund your next cyberpunk masterpiece. You’ve got until Sept. 30, 2022.

So what is a cyberdeck, exactly? That’s a surprisingly difficult question to answer, but since we’re running a contest here, we’ll have to give it a shot…

It needs to be a computer of some sort, certainly. It should also serve a practical purpose; as impressive as your cosplay prop might be, we’re really looking for functional devices here. Nominally that means it will have a keyboard and some kind of display, but  figuring out how it all connects and what form the components will take is where things get interesting.

Above all, it needs to be personal. What would your dream computer look like? What features would it have? There’s no right or wrong answer here — a good cyberdeck should be a reflection of the person who built it, and no two should ever be quite the same.

Need some inspiration? Not to worry, you’ve come to the right place. We’ve seen dozens of these custom machines over the last couple of years if you need some help to get moving in the right direction.

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Cyberdeck Brainstorming Hack Chat

Join us on Wednesday, August 10 at noon Pacific for the Cyberdeck Brainstorming Hack Chat!

If there’s one thing for sure about Hackaday, it’s that we keep a finger on the pulse of the hardware hacking community. Trends come and go, but they rarely slip by us, thanks to the constant supply of tips to hot projects that our loyal readers send in. It’s great to get a first look at these projects and see what kind of trends they represent, and to see how the community reacts to them. Some trends fade quickly, some catch on for a bit, and some really catch fire.

One trend that’s gotten pretty hot lately is the cyberdeck. Finding ways to squeeze a computer into a compact, field-ready package and make it useable is a challenge right off the bat. Adding the suite of sensors and peripherals that have become de rigueur for cyberdecks adds another level of complexity, and taking the build across the finish line with the proper cyberdeck aesthetic makes these gadgets super-fun to build and (hopefully) to use.

If cyberdecks sound like fun, you’re right! And to help us all get onboard the cyberdeck train, we’re going to mix things up with this Hack Chat. Rather than putting one person in the hot seat for our usual AMA-style discussion, we thought it would be fun to get everyone into a chat and brainstorm some cyberdeck designs. And to help seed the discussion, we’ve invited a bunch of hackers whose cyberdeck builds we’ve featured before:

join-hack-chatWe’re not sure everyone will be able to make it, but we are sure that the more cyberdeck-adjacent people we have in the chat, the better. Whether you’re a veteran builder or just starting your first build, you’re going to want to stop by this Hack Chat and get in on the discussion. Particularly because we’re just kicking off our new Cyberdeck Design Contest in about an hour (spoiler!), and this’ll be a great way to get going!

Our Hack Chats are live community events in the Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 10 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Hackaday Prize 2022: A Plasma Tweeter For Ultimate Clarity

In the world of audio there are a huge variety of esoteric technologies which are rarely seen. One such is the plasma tweeter, a type of loudspeaker which generates sound by modulating a small electrical discharge. The benefit of this design comes in its delivering the closest possible to a point audio source, in effect the theoretical ideal speaker for treble frequencies. They’re a little hazardous due to the voltage but aren’t too difficult to make, as demonstrated by [Mircemk] whose version uses a recycled power pentode tube — which is how it showed up in the Hack it Back round of the Hackaday Prize.

It can be thought of as a cousin of the Tesla coil, with the same resonant oscillator but no capacity hat. Instead the top of the coil ends in a point, from which in the perfect speaker a ball of plasma replaces the Tesla’s impressive sparks. In this case the pentode is joined by a high-voltage TV line output transistor as a bias supply, which is in turn modulated with the audio through a small amplifier. It sometimes needs the plasma teasing out of it through discharge to a screwdriver, but the result is a very effective and clear plasma tweeter.

If plasma tweeters interest you, we’ve featured them before.