Tackling Tremors With DIY Technology

[It’s Triggy!] had a problem to solve. His grandma was having issues with hand tremors, which made the basic tasks of daily life difficult to perform. He decided to explore whether a high-tech solution could help best the tremors and make life easier.

The video covers multiple ideas on how to stabilize a hand suffering involuntary tremors. The first build involved a gyroscope, which proved unsuccessful, but led to the idea of building a reaction wheel. The concept is simple — get the reaction wheel to counteract the forces from tremors to stabilize the hand. To achieve this, an accelerometer was employed to track the movements of the arm and the hand. The magnitude of the movement was then used to control a powerful brushless motor mounted on the wrist. If the tremor was driving a hard tilt to the left, the motor would spin up to create a counter-torque, cancelling out the involuntary movement. This worked to a degree, but the resulting device was large and noisy, which made it impractical.

This thus inspired a return to earlier work involving the use of a tuned mass damper to settle tremors. The combination of some 3D printed wrist mounts along with various spring and cantilever designs… ultimately didn’t work that well. By this point, [It’s Triggy!] had noticed the tremor was mostly in the hands, while the wrist stayed steady. Thus was inspired a wrist-mounted handle for the wearer to wrap their hand around. This allowed the use of simple handheld objects like kitchen utensils, with the wearer’s own grip suppressing the tremor successfully.

As this project demonstrates, sometimes high-tech solutions are the way to go, and other times… a more passive design will actually serve you better.

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High-Speed Pocket Hot Dog Cooker

Few of us complain that hot dogs take too long to cook, because we buy them from a stand. Still, if you do have to make your own dog, it can be a frustrating problem. To solve this issue, [Joel Creates] whipped up a solution to cook hot dogs nearly instantaneously. What’s more, it even fits in your pocket!

The idea behind this build is the same as the classic Presto hot dog cooker—pass electricity through a hot dog frank, and it’ll heat up just like any other resistive heating element. To achieve this, [Joel] hooked up a lithium-polymer pack to a 12-volt to 120-volt inverter. The 120-volt output was hooked up to a frank, but it didn’t really cook much. [Joel] then realized the problem—he needed bigger electrodes conducting electricity into the sausage. With 120 volts pumping through a couple of bolts jammed into either end of the frank, he had it cooked in two minutes flat.

All that was left to do was to get this concept working in a compact, portable package. What ensued was testing with a variety of boost converter circuits to take power from the batteries and stepping it up to a high enough voltage to cook with. That, and solving the issue of nasty chemical byproducts produced from passing electricity through the sausages themselves. Eventually, [Joel] comes up with a working prototype which can electrically cook a hot dog to the point of shooting out violent bursts of steam in under two minutes. You’d still have to be pretty brave to eat something that came out of this thing.

The biggest problem with hot dogs remains that the franks are sold in packs of four while buns are sold in packs of six. Nobody’s solved that problem yet, except for those hateful people who inexplicably have eleven friends. If you solve that one, don’t hesitate to notify the tipsline. Don’t forget, either, that the common hot dog can make for an excellent LED tester. Video after the break.

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Internet-Connected Consoles Are Retro Now, And That Means Problems

A long time ago, there was a big difference between PC and console gaming. The former often came with headaches. You’d fight with drivers, struggle with crashes, and grow ever more frustrated dealing with CD piracy checks and endless patches and updates. Meanwhile, consoles offered the exact opposite experience—just slam in a cartridge, and go!

That beautiful feature fell away when consoles joined the Internet. Suddenly there were servers to sign in to and updates to download and a whole bunch of hoops to jump through before you even got to play a game. Now, those early generations of Internet-connected consoles are becoming retro, and that’s introduced a whole new set of problems now the infrastructure is dying or dead. Boot up and play? You must be joking!

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How To Build Good Contact Mics

We’re most familiar with sound as vibrations that travel through the atmosphere around us. However, sound can also travel through objects, too! If you want to pick it up, you’d do well to start with a contact mic. Thankfully, [The Sound of Machines] has a great primer on how to build one yourself. Check out the video below.

The key to the contact mic is the piezo disc. It’s an element that leverages the piezoelectric effect, converting physical vibration directly into an electrical signal. You can get them in various sizes; smaller ones fit into tight spaces, while larger ones perform better across a wider frequency range.

[The Sound of Machines] explains how to take these simple piezo discs and solder them up with connectors and shielded wire to make them into practical microphones you can use in the field. The video goes down to the bare basics, so even if you’re totally new to electronics, you should be able to follow along. It also covers how to switch up the design to use two piezo discs to deliver a balanced signal over an XLR connector, which can significantly reduce noise.

There’s even a quick exploration of creative techniques, such as building contact mics with things like bendable arms or suction cups to make them easier to mount wherever you need them. A follow-up explores the benefits of active amplification. The demos in the video are great, too. We hear the sound of contact mics immersed in boiling water, pressed up against cracking spaghetti, and even dunked in a pool. It’s all top stuff.

These contact mics are great for all kinds of stuff, from recording foley sounds to building reverb machines out of trash cans and lamps.

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Shoot Instax Film In A Polaroid Camera With The Aid Of Tape

Polaroid cameras have been very popular for a very long time and are especially hot gifts this year. Fresh film is easy to find but relatively expensive. In contrast, Fuji’s Instax line of instant film and cameras aren’t as well established, but the film is easy to find and cheap. You might like to shoot cheap Instax film in your Polaroid camera. Thankfully, [Nick LoPresti] figured out how to do just that.

You can’t just slam an Instax cassette in an old Polaroid camera and expect it to work. The films are completely different sizes, and there’s no way they will feed properly through the camera’s mechanisms at all. Instead, you have to get manual about things. [Nick] starts by explaining the process of removing Instax film sheets from a cassette, which must be done without exposure to light if you want the film to remain useful. Then, if you know what you’re doing, you can tape it in place behind the lens of an old-school Polaroid camera, and expose it as you would any other shot. The chemistry is close enough that you’ll have a fair chance of getting something with passable exposure.

Once exposed, you have to develop the film. Normally, a Polaroid camera achieves this by squeezing the film sheet out through rollers to release the developer and start the process. Without being able to rely on the camera’s autofeed system, you need to find an alternative way to squeeze out the chemicals and get the image to develop. [Nick] recommends a simple kitchen rolling pin, while noting that you might struggle with some uneven chemical spread across the sheet. Ultimately, it’s a fussy hack, but it does work. It might only be worthwhile if you’ve got lots of Instax film kicking around and no other way to shoot it.

Instant cameras can seem a little arcane, but they’re actually quite simple to understand once you know how they’re built. You can even 3D print one from scratch if you’re so inclined. Video after the break.

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Cheap 3D Printer Becomes CNC Wood Engraver

3D printers are built for additive manufacturing. However, at heart, they are really just simple CNC motion platforms, and can be readily repurposed to other tasks. As [Arseniy] demonstrates, it’s not that hard to take a cheap 3D printer and turn it into a viable wood engraver.

The first attempt involved a simple experiment—heating the 3D printer nozzle, and moving it into contact with a piece of wood to see if it could successfully leave a mark. This worked well, producing results very similar to a cheap laser engraving machine. From there, [Arseniy] set about fixing the wood with some simple 3D-printed clamps so it wouldn’t move during more complex burning/engraving tasks. He also figured out a neat trick to simply calibrate the right Z height for wood burning by using the built in calibration routines. Further experiments involved developing a tool for creating quality G-Code for these engraving tasks, and even using the same techniques on leather with great success.

If you need to mark some patterns on wood and you already have a 3D printer, this could be a great way to go. [Arseniy] used it to great effect in the production of a plywood dance pad. We’ve featured some other great engraver builds over the years, too, including this innovative laser-based project. Video after the break.

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Windmill Desk Lamp Is Beautifully Soothing

Typically, lamps provide a stationary source of light to illuminate a given area and help us see what we’re doing. However, they can also be a little more artistic and eye-catching, like this windmill lamp from [Huy Vector].

It’s somewhat of a charming desk toy, constructed out of copper wire soldered into the form of a traditional windmill. At its base, lives a simple motor speed controller, while up top, a brushed DC gearmotor is responsible for turning the blades. As you might imagine, it’s a little tricky to get power to flow to the LED filaments installed on those blades while they happen to be rotating. That’s where the build gets tricky, using the output shaft of the motor’s gear drive and a custom slip ring to pass power to the LEDs. That power comes courtesy of a pair of 16340 lithium-ion cells, which can be juiced up with the aid of a USB-C charger board.

It’s an elegant build, and rather charming to watch in motion to boot. We love a good lamp build here at Hackaday, particularly when they’re aesthetically beautiful.

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