There Are Stradi-various Ways To Make A Violin, And This Is One

January 8, 2024 by 14 Comments

We’ve always said that if we had enough money, we’d have a large room that housed every musical instrument we’ve ever been even mildly interested in. While that dream may never come to pass, it would be far more likely to happen if many of the instruments could be 3D-printed, like this electric violin.

We really like this compact design, which mimics a headless guitar with the tuning pegs down by the bridge. [Carmensr] started with a model on Thingiverse, which uses violin strings wound around electric guitar tuners instead of wooden friction pegs. To further the guitar comparison, the three-piece neck contains a truss rod of sorts.

So how does it work, though? The magic is in the special bridge, which contains a piezo element. The bridge picks up the strings’ vibrations and sends them to a little pre-amplifier, which creates a signal that can then be used by a program like Audacity or connected directly to a speaker. Be sure to give it a listen in the video after the break.

Of course, there’s no reason not to design and print acoustic violins. It would be fun to experiment with different filaments for different sounds.

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Make Your Own Play Station (The Space Is Important)

January 8, 2024 by 20 Comments

The early history of the Sony Playstation lies in a stillborn collaboration between Nintendo and Sony to produce an SNES with a CD-ROM drive. So the story goes, Nintendo’s Philips deal angered Sony, who decided to make their own console line, and the rest is history. A very small number of prototypes were made, badged as “Play Station,” and should you find one that escaped today, you’re sitting on a fortune. [James] doesn’t have one, but he did have half a Playstation and an SNES shell, so he could make an ungodly child of the two consoles that you can see in the video below the break.

Those Playstation CD-ROM drives were notorious for melting back in the day, so it’s no surprise they’re still for sale today. Thus, he was able to bring the Sony back to life. What follows is an episode of console cutting worthy of a slasher horror movie, as instead of a bit of fine Dremmeling, he brings out an angle grinder and slices away with abandon. We don’t like the Nintendo switch carrying mains voltage, but we’re fine with the PlayStation expansion connector going away. The Nintendo eject button needs a hack to operate the Playstation door open button when pressed. It’s cool to see the board has a mod chip. We used to fit those as a sideline in a previous life. Continue reading “Make Your Own Play Station (The Space Is Important)” →

Liquid Tin Could Be The Key To Cheap, Plentiful Grid Storage

January 8, 2024 by 143 Comments

Once expensive and difficult to implement, renewable energy solutions like wind and solar are now often the cheapest options available for generating electricity for the grid. However, there are still some issues around the non-continuous supply from these sources, with grid storage becoming a key technology to keep the lights on around the clock.

In the quest for cost-effective grid storage, a new player has entered the arena with a bold claim: a thermal battery technology that’s not only more than 10 times cheaper than lithium-ion batteries, but also a standout in efficiency compared to traditional thermal battery designs. Fourth Power is making waves with its “sun in a box” energy storage technology, and aims to prove its capabilities with an ambitious 1-MWh prototype.

Hot Stuff

Simple heating elements turn electricity into heat, putting it into liquid tin that then heats large graphite blocks. Credit: Fourth Power, Vimeo screenshot

The principle behind Fourth Power’s technology is deceptively simple: when there’s excess renewable energy available, use it to heat something up. The electrical energy is thus converted and stored as heat, with the idea being to convert it back to electricity when needed, such as at night time or when the wind isn’t blowing. This concept isn’t entirely new; other companies have explored doing this with everything from bricks to molten salt. Fourth Power’s approach involves heating large blocks of graphite to extremely high temperatures — as high as 2,500 °C (4,530 °F). Naturally, the hotter you go, the more energy you can store. Where the company’s concept gets interesting is how it plans to recover the heat energy and turn it back into electricity.

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Bringing A Chain Printer Back To Life: The Power Supply

January 8, 2024 by 25 Comments

[Usagi Electric] has his Centurion minicomputer (and a few others) running like a top.  One feature that’s missing, though, is the ability to produce a hard copy. Now, a serious machine like the Centurion demands a serious printer. The answer to that is an ODEC-manufactured printer dressed in proper Centurion blue. This is no ordinary desktop printer, though. It’s a roughly 175lb (80 Kg) beast capable of printing 100 lines per minute. Each line is 132 characters wide, printed on the tractor-feed green bar paper we all associate with old computer systems.

This sort of printer was commonly known as a chain printer, as the letters are on a chain that rides over a series of 66 hammers. Logic on this printer is 74 series logic chips – no custom silicon or LSI (Large Scale Integration) parts on this 47-year-old monster.

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Half Power Bank, Half Spot Welder

January 8, 2024 by 13 Comments

There was a time when every gizmo on AliExpress also had a big white LED so it could also work as a flashlight, but maybe the power bank is the new flashlight. [Aaron Christophel] has a battery spot welder that costs a not unreasonable 30 euros and can also be used as a novelty power bank. He subjects it to a test and teardown in the video below the break.

First of all, he conducts a few weld tests, and we have to say it seems capable of some reasonable results if its parameters are correctly adjusted. Then the end comes off the extruded aluminium case, and the guts of the device are slid out for a teardown.

The power comes from a pair of Li-Po pouch cells, while on the board, there’s an STM32 clone providing the timing for a set of MOSFETs that do the heavy lifting. There’s a colour display for tweaking the settings. Alongside all this, there’s also a small chip for that power bank functionality. Charging is via USB-C, though, of course, it’s not really proper USB-C but a USB-C socket that expects 5 volts. This is a disappointing trend in cheap electronics that sullys the promise of USB-C.

It seems this spot welder is capable of doing the job, which is pleasing after our previous disappointing look at battery welders.

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Discovery Dish Lets You Pick Up The Final Frontier

January 7, 2024 by 15 Comments

These days, affordable software defined radios (SDRs) have made huge swaths of the spectrum available to hobbyists. Whether you’re looking to sniff the data from that 433 MHz thermometer you’ve got in the backyard or pick up transmissions from satellites, the same little USB-connected box can make it happen.

But even the best SDR is constrained by the antenna it’s connected to, and that’s where it can still get a little tricky for new players. Luckily, there’s a new option for those who want to pick up signals from space without breaking the bank: the Discovery Dish by KrakenRF. After reaching 105% of its funding goal on December 20th, the handy little 65-cm aluminum reflector looks like it’s on track to ship out this summer.

The Discovery Dish was designed from the ground up to enable hobbyists to receive real-time weather data from satellites transmitting in the L band (GOES, NOAA, Meteor, etc.) and experiment with hydrogen line radio astronomy. Neither of which are anything new, of course. But having a pre-built dish and feed takes a lot of the hassle out of picking up these distant signals.

Although the current prototype has a one-piece reflector, the final Discovery Dish will break down into three “petals” to make storage and transport easier. If you don’t want to take it all the way apart, you can simply remove the feed to make it a bit more compact. Speaking of which, KrakenRF is also offering three different feeds depending on what signals you’re after: L band, Inmarsat, or hydrogen line.

You still have options if you’ve got to keep your radio hacking on a tighter budget. As we saw recently, you can actually pull an ET and pick up weather satellites using a foil-lined umbrella. Or spend a little at the big box hardware store and grab some aluminum flashing.

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World’s First Precision Lathe: Indispensable When Constructing The Antikythera Mechanism

January 7, 2024 by 27 Comments
The precision lathe with the hooks, the bowstring, and vise visible as material is being processed. (Credit: Clickspring)

We commonly tend to associate lathes with the Industrial Revolution, when metalworking shifted largely from blacksmiths to machinists, but the use of lathes is much older than that. As [Chris] over at the Clickspring YouTube channel demonstrates in a recent video, small precision lathes were exceedingly common in the Ancient World. Not only is there ample historical evidence of them being used as far back as 1300 BCE in Ancient Egypt, but they’re also the most optimal way to get perfectly round pins and other, more intricate shapes that would be an absolute nightmare to create with just some metal files and chisels.

In the video, [Chris] uses two metal hooks, bent in a ninety-degree angle and clamped down in a vise, tapering towards each other into points. A bow string around a round piece of wood is used to bootstrap a more permanent retention element and bushing for the bow string as it is drawn over the wood to rotate it. Subsequent material that has to be worked on in the lathe is then clamped between the two points. This way, using basic materials that have been around for thousands of years and some muscle power, it’s possible to create a small lathe that can be used to create perfectly symmetrical shapes, such as those used in the construction of the Antikythera Mechanism, which [Chris] has been rebuilding for the past years, using only period-correct tools. He’s learned a lot about the mechanism in the process.

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