Month: December 2019

Building An Engine With An A/C Compressor

December 4, 2019 by 38 Comments

Air conditioning compressors aren’t exactly a mainstay of the average hacker’s junk box. Typically, they’re either fitted to a car to do their original job, or they’re on the bench getting refurbished. However, with the right mods, it’s possible to turn one into a functioning internal combustion engine.

The build starts by disassembling the compressor, which contains three double-sided pistons. The housing is drilled with ports to allow gas to flow into and out of the cylinders, as well as to transfer from one side of the piston to the other. Acrylic end plates are fitted to the assembly. One end acts as an intake manifold, delivering air and fuel to the cylinders. The other side acts as the cylinder head, mounting the sparkplugs. Everything is then connected with acrylic tubing and a small square section of acrylic is turned into a carburetor to supply the air-fuel mix. Ignition is handled by coils triggered by the movement of the flywheel.

After an initial failure due to the acrylic manifold cracking, a stronger part is fabricated, and the engine bursts into life. The acrylic end caps give a great view of the combustion process in action. We’d love to see the a dyno graph on how much power and torque the unit puts out, or to see it hooked up to a bicycle or cart.

We’ve seen others attempt their own engine builds, too. If you’ve got an unconventional engine build of your own, be sure to let us know. Video after the break.

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Start Your Day With The Mountain That Rises

December 4, 2019 by 3 Comments

Like many of us, [Zach Archer] enjoys the comfort of his darkened room so much that he has trouble getting up and facing the day. To make things a little easier for himself, he decided to put together a custom alarm clock that would fill his mornings with the glorious glow of LEDs; and since he finds the mountains an inspirational sight he decided to wrap the whole thing up in a 3D printed enclosure that resembles snow capped peaks.

But even Bob Ross himself couldn’t have imagined a snowy mountain range that featured an integrated e-ink screen. The big 4.2″ panel is connected to a custom designed PCB by [romkey], which was graciously donated for this project. An ESP32 runs the show, providing a convenient web interface to control not only the clock, but various aspects of the mountain’s internal LEDs such as fade in time and total duration.

[Zach] says he originally printed the mountains in PLA, but the heat generated by the LEDs eventually started to cause things to warp. Switching over to translucent PETG not only solved the heat problem, but made for a very effective LED diffuser. Rather than complex animation patterns, he’s found that smoothly transitioning between different shades of blue and green seems to work best for him in the mornings.

This isn’t the first time we’ve seen somebody use LEDs to get them out of bed in the morning, but we do appreciate the aesthetic that [Zach] has achieved here between the design of the mountains and the impressive artwork on the e-ink display. Then again, we’re also quite partial to this version that looks like a warp core, so our tastes do run the gamut.

Sara Adkins Is Jamming Out With Machines

December 4, 2019 by 1 Comment

Asking machines to make music by themselves is kind of a strange notion. They’re machines, after all. They don’t feel happy or hurt, and as far as we know, they don’t long for the affections of other machines. Humans like to think of music as being a strictly human thing, a passionate undertaking so nuanced and emotion-based that a machine could never begin to understand the feeling that goes into the process of making music, or even the simple enjoyment of it.

The idea of humans and machines having a jam session together is even stranger. But oddly enough, the principles of the jam session may be exactly what machines need to begin to understand musical expression. As Sara Adkins explains in her enlightening 2019 Hackaday Superconference talk, Creating with the Machine, humans and machines have a lot to learn from each other.

To a human musician, a machine’s speed and accuracy are enviable. So is its ability to make instant transitions between notes and chords. Humans are slow to learn these transitions and have to practice going back and forth repeatedly to build muscle memory. If the machine were capable, it would likely envy the human in terms of passionate performance and musical expression.

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The Story Of A Secret Underground Parisian Society

December 4, 2019 by 28 Comments

Deep in the heart of Paris, a series of underground tunnels snakes across the city. They cross into unkept public spaces from centuries ago that have since vanished from collective memory – abandoned basements, catacombs, and subways hundreds of miles apart.

Only a few groups still traverse these subterranean streets. One that came into public view a few years ago, Les UX (Urban eXperiment), has since claimed several refurbished developments, including restoring the long neglected Pantheon clock and building an underground cinema, complete with a bar and restaurant.

While the streets of Paris are tame during the day, at night is when Les UX really comes alive. A typical night might involve hiding in the shadows away from potential authorities roaming the streets, descending into the tunnels through a grate in the road, and carrying materials to an agreed upon drop off location. Other nights might involve wedging and climbing over pipes and ladders, following the routes into the basements of buildings left unguarded.
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[Ben Krasnow] Builds A Mass Spectrometer

December 4, 2019 by 31 Comments

One of the features that made Scientific American magazine great was a column called “The Amateur Scientist.” Every month, readers were treated to experiments that could be done at home, or some scientific apparatus that could be built on the cheap. Luckily, [Ben Krasnow]’s fans remember the series and urged him to tackle a build from it: a DIY mass spectrometer. (Video, embedded below the break.)

[Ben] just released the video below showing early experiments with a copper tube contraption that was five months in the making; it turns out that analytical particle physics isn’t as easy as it sounds. The idea behind mas spectrometry is to ionize a sample, accelerate the ions as they pass through a magnetic field, and measure the deflection of the particles as a function of their mass-to-charge ratio. But as [Ben] discovered, the details of turning a simple principle into a working instrument are extremely non-trivial.

His rig uses filaments extracted from carefully crushed incandescent lamps to ionize samples of potassium iodide chloride; applied to the filament and dried, the salt solution is ionized when the filament is heated. The stream of ions is accelerated by a high-voltage field and streamed through a narrow slit formed by two razor blades. A detector sits orthogonal to the emitter across a powerful magnetic field, with a high-gain trans-impedance amplifier connected. With old analog meters and big variacs, the whole thing has a great mad scientist vibe to it that reminds us a bit of his one-component interferometer setup.

[Ben]’s data from the potassium sample agreed with expected results, and the instrument is almost sensitive enough to discern the difference between two different isotopes of potassium. He promises upgrades to the mass spec in the future, including perhaps laser ionization of the samples. We’re looking forward to that.

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Can You Store Renewable Energy In A Big Pile Of Gravel?

December 4, 2019 by 117 Comments

As the world grapples with transitioning away from fossil fuels, engineers are hard at work to integrate new types of generation into the power grid. There’s plenty of challenges, particularly around the intermittent nature of many renewable energy sources. Energy storage projects are key to keeping the lights on round the clock, even when the wind isn’t blowing and the sun isn’t shining.

Conventional grid-level energy storage has long made use of pumped hydro installations where water is pumped uphill to a storage reservoir where it can later be used to run a generator. More recently, batteries are being used to do the job. When you consider the cost of these installations and their storage capacities, there is a gap between batteries and pumped hydro. A recently published whitepaper proposes Mountain Gravity Energy Storage — gravity-based energy storage using sand or gravel in mountainous areas — is the technology that can bridge the gap.

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Zombies Ate Your Neighbors? Tell Everyone Through LoRa!

December 4, 2019 by 24 Comments

As popular as the post-apocalyptic Zombie genre is, there is a quite unrealistic component to most of the stories. Well, apart from the whole “the undead roaming the Earth” thing. But where are the nerds, and where is all the apocalypse-proof, solar-powered tech? Or is it exactly this lack of tech in those stories that serves as incentive to build it in the first place? Well, maybe it doesn’t have to be the end of the world to seek for ways to cope with a collapse of our modern communication infrastructure either. Just think of natural disasters — an earthquake or hurricane causing a long-term power outage for example. The folks at [sudomesh] tackle exactly this concern with their fully open source, off-grid, solar-powered, LoRa mesh network, Disaster Radio.

The network itself is built from single nodes comprising of a battery-backed solar panel, a LoRa module, and either the ESP8266 or ESP32 for WiFi connectivity. The idea is to connect to the network with your mobile phone through WiFi, therefore eliminating any need for additional components to actually use the network, and have the nodes communicate with each other via LoRa. Admittedly, LoRa may not be your best choice for high data rates, but it is a good choice for long-range communication when cellular networks aren’t an option. And while you can built it all by yourself with everything available on [sudomesh]’s GitHub page, a TTGO ESP32 LoRa module will do as well.

If the idea itself sounds familiar, we did indeed cover similar projects like HELPER and Skrypt earlier this year, showing that LoRa really seems to be a popular go-to for off-grid communication. But well, whether we really care about modern communication and helping each other out when all hell breaks loose instead of just primevally defending our own lives is of course another question.