Kritik sah

Bicycles need at least two wheels to be rideable, but [The Q] realized you don’t necessarily need the wheels to be in one piece. As long as you have at least two points of rolling contact with the ground, you can spread the load across multiple partial wheels. He demonstrated this by splitting the rear wheel of his bike first in half and then thirds to create an absolute head turner. Since a conventional bicycle wheel with tensioned spokes would collapse if cut apart, [The Q] used single-piece aluminum wheels instead. The tires were cut into pieces, and the inner tubes were replaced with sections of thick-walled HDPE pipe that won’t collapse under the weight of a human. The tires and the HDPE “inner tubes” were riveted to the wheels. To mount the additional wheels on the frame, [The Q] welded a set of extensions to the back with mounting points for the partial wheels. To keep them synced, timing is done with chains running on sprockets welded to the disc brakes. In the second vide

It’s summer time in the Northern Hemisphere, and that means campfires for cooking hot dogs, keeping the mosquitoes away, and of course, making s’mores. For our far-flung friends, that’s a fire roasted marshmallow and a square of chocolate smashed between two graham crackers. So called because when you’re done, you’ll want s’more. It’s an easy enough recipe that any child can tell you how to make it. But what if you’re not a child? What if you don’t even have hands , because you’re an industrial robot? This is the challenge that [Excessive Overkill] has taken on in the video below the break . Starting with a Fanuc S-420 i W industrial robot built in 1997, [Excessive Overkill] painstakingly taught his own personal robot how to make S’Mores. Hacking the microwave with pneumatic cylinders to get the door open was a nice touch, and so are the vacuum grippers at the business end of the S’More-bot. We know, we said you were supposed to make them on a campfire — but who wants to risk cooki

Don’t look up! As of the time of this writing, there’s a decent chance that a Chinese Long March 5B booster has already completed its uncontrolled return to Earth , hopefully safely. The reentry prediction was continually tweaked over the last week or so, until the consensus closed in on 30 Jul 2022 at 17:08 UTC , give or take an hour either way. That two-hour window makes for a LOT of uncertainty about where the 25-ton piece of space debris will end up. Given the last prediction by The Aerospace Corporation, the likely surface paths cover a lot of open ocean, with only parts of Mexico and South America potentially in the crosshairs, along with parts of Indonesia. It’s expected that most of the material in the massive booster will burn up in the atmosphere, but with the size of the thing, even 20% making it to the ground could be catastrophic, as it nearly was in 2020 . [ Update : US Space Command confirms that the booster splashed down in the Indian Ocean region at 16:45 UTC. No wo

If Nintendo is known for anything outside of their characters and admittedly top-notch video games, it’s being merciless to fans when it comes to using their intellectual property. They take legal action against people just for showing non-Nintendo hardware emulating games of theirs, and have even attempted to shut down the competitive scene for games like Super Smash Bros . To get away from the prying eyes of the Nintendo legal team extreme measures need to be taken — like building your Nintendo console clone behind the Iron Curtain . [Marek Więcek] grew up in just such a place, so the only way to play Famicom (a.k.a NES) games was to use a clone system like this one circulating in the Eastern Bloc at the time called the Pegasus which could get the job done with some tinkering. [Marek] recently came across CPU and GPU chips from this clone console and got to work building his own. Using perf board and wire he was able to test the chips and confirm they functioned properly, but had a

Seeing his wife try to use a cool face mask to get through the pain of a migraine headache, [Sparks and Code] started thinking of ways to improve the situation. The desire to save her from these debilitating bouts of pain drove him to make an actively cooled mask , all the while creating his own headache of an over-engineered mess. Void spaces inside the printed mask are filled with chilled water. Instead of having to put the face mask into the refrigerator to get it cold, [Sparks and Code] wanted to build a mask that he could circulate chilled water through. With a large enough ice-filled reservoir, he figured the mask should be able to stay at a soothing temperature for hours, reducing the need for trips to the fridge. [Sparks and Code] started out by using photogrammetry to get a 3D model of his wife’s face. Lack of a compatible computer and CUDA-enabled GPU meant using Google Cloud to do the heavy lifting. When they started making the face mask, things got complicated. And t

It’s not every day we see the results of someone putting their own spin on a vintage tube amp, but that’s exactly what [lens42] did in creating the McIntosh 217, created as a “mini” version of the McIntosh MC275 , a classic piece of audio equipment. Both are pictured next to each other, above. When it comes to vintage hi-fi stereo amplifiers, two units had particular meaning for [lens42]: the McIntosh MC275 Power Amp, and the Dynaco ST35. The Dynaco was a more budget-friendly amplifier, but looked like a plain box. The McIntosh, however, proudly showed off its tubes and transformers in all their glory. The “McIntosh 217” is design-wise basically a smaller McIntosh MC275, with the innards of a Dynaco ST35. With so much needing to be designed from the ground up, CAD was invaluable. Component layout, enclosure design, and even wiring and labeling all had to be nailed down as much as possible before so much as heating up the soldering iron. Even so, there were a few hiccups; a vendor ha

There is something inherently fascinating about tiny mechanical devices, especially when you’re used to seeing much larger versions. This is the case with [Penguin DIY]’s tiny centrifugal water pump built from 5 ml syringes. The pump is powered by a small 8 mm diameter brushed DC motor, likely the same type that is used for small toy-grade quadcopters. The tiny impeller is a section of the syringe’s original plunger, with its cross-shaped body acting as the impeller blades. [Penguin DIY] first experimented with the original plunger seal to protect the motor from water, but it quickly melted from friction with the spinning shaft. Silicone sealant was used instead, and the motor shaft was covered with a layer of oil to prevent the sealant from sticking to it. Then the blob of sealant was flattened with a translucent plastic disc to allow clearance for the impeller. A hole was drilled in the side of the syringe where the impeller sits, and a nozzle cut from the tip of another syringe

Film scanners are a useful tool for digitizing slides and negatives, and the Plustek 8100 that [Christian Chapman] had was capable, but limited to small format film only. Rather than pay for a much more expensive medium format scanner that could handle 120 film, he modified his 8100 to accomplish the same thing with a combination of good old software and hardware tampering. On the software side, [Christian] modified a driver for the Plustek 8100 so that it sweeps the scan head further than usual. At the application level, to scan medium format frames, it does a total of four scans: one for each quadrant. The results get stitched together in software with a thoughtfully-designed shell script that provides previews and handles failures and restarts gracefully. Hardware-wise, the scanning carriage needs modification to ensure nothing interferes with the scan head as it moves further than originally designed. Some CAD and 3D printing made short work of this . Incidentally, this hardwa

As the saying goes, nothing can be said to be certain, except death, taxes, and the never-ending inventiveness of clock hacks. No matter how tried and proven a concept is, someone will always find a new twist for it. Case in point: notorious clock builder [Shinsaku Hiura] took the good old split-flap display approach, and mixed things up by using a deck of playing cards to actually represent the time . Technically, the clock works just like a regular flip clock, except that only the upper half of the split-flap is used to display the digits, while the lower half is showing the cards’ backsides. Other than that, the mechanics are the same: a set of hinges holding the cards are arranged on a rotor that’s moved by a stepper motor until the correct digit is shown ( STLs available on Thingiverse ). Aces low, Jokers are zeroes, and the queen strikes at noon. At the center of it is an ESP32 that controls each digit’s motor driver, and retrieves the time via WiFi, keeping the general compon

[Walker] has a very interesting new project: a completely different take on a self-destructing USB drive . Instead of relying on encryption or other “visible” security features, this device looks and works like an utterly normal USB drive. The only difference is this: if an unauthorized person plugs it in, there’s no data. What separates authorized access from unauthorized? Wet fingers. It sounds weird, but let’s walk through the thinking behind the concept. First, encryption is of course the technologically sound and correct solution to data security. But in some environments, the mere presence of encryption technology can be considered incriminating. In such environments, it is better for the drive to appear completely normal. Toggling the chip enable (CE) pin will hide the drive’s contents. The second part is the access control; the “wet fingers” part. [Walker] plans to have hidden electrodes surreptitiously measure the resistance of a user’s finger when it’s being plugged in

When Datamedia announced their new DT80 terminal as a VT100 killer back in 1979, they were so confident of its reliability, they threw in a full one-year warranty. Now, decades later, that confidence is once more put to the touch after [RingingResonance] fished one such terminal out of a creek by an old illegal dumping site. Not knowing what to expect from the muck-ridden artifact, his journey of slowly breathing life back into the device began . Brings new meaning to the term “rooted” Considering the layers of mud and roots already growing all over the main board, one can only assume how long the terminal has actually been in there. But cleaning it from all that was only the beginning: some components were missing, others turned out to be broken, including some of the ROMs, which [RingingResonance] speculates may have been caused by lightning which determined the DT80’s fate in the first place. That’s when the adventure really started though, digging deep into the terminal’s in

Dan Maloney and I were talking about the chess robot arm that broke a child’s finger during the podcast, and it turns out that we both have extreme respect for robot arms in particular. Dan had a story of a broken encoder wheel that lead to out-of-control behavior that almost hit him, and I won’t even get within striking distance of the things unless I know they’re powered off after seeing what programming errors in a perfectly functioning machine can do to two-by-fours. This made me think of all the dangerous things I’ve done, but moreover about all the intensely simple precautions you can to render them non-risky, and I think that’s extremely important to talk about. Tops of my list are the aforementioned industrial robot arm and high powered lasers. Staying safe with an industrial robot arm is as easy as staying out of reach when it’s powered. Our procedure was to draw a line on the floor that traced the arm’s maximum radius, and you stay always outside that line when the light

Vintage electronics and capacitor replacements tend to go hand-in-hand. Why? Because electrolytic capacitors just don’t last , not the way most other components do, anyway. The metal terminal ring and the central plate are kept for re-use, and the metal case re-crimped after the internals of the capacitor are replaced with a modern equivalent. It’s one thing to swap old caps with modern replacements, but what about electronics where the components are not hidden away, and are an important part of the equipment’s look? [lens42] shares a method for replacing antique can-style capacitors in a way that leaves them looking completely original . All it takes is some careful application of technique. The first thing to do is carefully file away the crimp of the metal can until one can release the ring and plate that hold the terminals. Once that is off, the internals can be pulled from the metal can for disposal. Since the insides of the old cap won’t be re-used, [lens42] recommends sim

We’ve noticed that [Carl Bugeja] likes flexible PCBs. His latest exploit is to make PCB-based springs that combine with some magnets to create little devices that jump . We aren’t sure what practical use these might have, but they are undeniably novel and you can see them — um — jumping around, in the video, below. [Carl] did many experiments with the spring construction and design. You can see several of the iterations in the video, not all of which worked out well. A PCB coil in the base becomes magnetized when current flows and this repels or attracts the magnets at the other end of the spring. What can you do with a PCB spring? We aren’t sure. Maybe this is how your next microrobot could climb stairs? Adding stiffeners produced springs too stiff for the electromagnet to attract. We wondered if a different coil design at the base might be more effective. For that matter, you might not have to use a flat PCB coil in that position if you were really wanting to optimize the jumping

There are many ways to test HF antennas ranging from simulation to various antenna analyzers and bridges. However, nothing can replace simply using the antenna to see how it works. Just as — supposedly — the bumblebee can’t fly, but it does so anyway, it is possible to load up some bed springs and make contacts. But it used to be difficult — although fun — to gather a lot of empirical data about antenna performance. Now you can do it all with WSPR and [TechMinds] suggests a moderately-priced dedicated WSPR transmitter to do the job . You can see a video about the results of this technique below. While WSPR is often cited as taking the fun out of ham radio, it is perfect for this application. Connect the transmitter and a few hours later, visit a web page and find out where you’ve been heard by an objective observer. If you had a few of these, you could even examine several antennas at similar times and conditions. The transmitter has its own GPS so it doesn’t require much configura

If you had the traditional engineering education, you’ve made your peace with calculus. If you haven’t, you may have learned it on your own, but for many people, calculus has a reputation for being super difficult. While some of the details can be very tricky, the core concepts are actually simple and [Mathologer] has a very simple explanation along with some good graphics that can help you get started on calculus mastery if you’ve been putting it off. Using a car on the highway as the prototypical example, he covers quite a bit of ground in the 30 minute video that you can see below. Of course, this isn’t a unique idea that calculus is actually simple. The video credits the great book “Calculus Made Easy” that we’ve talked about before. That 100-year-old (and then some) book has a similar approach to the topic. Unlike a lot of similar videos, this one covers more complex things like various rules and the integral and derivative of trig functions and logarithms. It presents them

Meet [Tanner] . [Tanner] is a hacker who also appreciates the security of their home while they’re out of town. After doing some research about home security, they found that it doesn’t take much to keep a house from being broken into. It’s true that truly determined burglars might be more difficult to avoid. But, for the opportunistic types who don’t like having their appendages treated like a chew toy or their face on the local news, the steaks are lowered.  All it might take is a security camera or two, or a big barking dog to send them on their way. Rather than running to the local animal shelter, [Tanner] used parts that were already sitting around to create a solution to the problem: A computer vision triggered virtual dog . An actual burglar caught by [Tanner]’s surveillance, and an inspiration for the project The hardware for the computer canine is simple: A surveillance camera feeds images to a Raspberry Pi which, when triggered plays the sound of a dog barking. But [Tan

No matter the type of vehicle we drive, it has a battery. Those batteries wear out over time. Even high end EV’s have batteries with a finite life. But when your EV uses Lead Acid batteries, that life is measured on a much shorter scale. This is especially true when the EV is driven by a driver that takes up scarcely more space in their EV than a stuffed tiger toy! Thankfully, the little girl in question has a mechanic: A 3d printed adapter sends go-juice to the DC-DC converter Her daddy, [Brian Lough], who documented the swift conversion of his daughter’s toy truck from Lead Acid to Li-Ion in the video which you can see below the break . Facing challenges similar to that of actual road worthy passenger vehicles, [Brian] teamed up with [ bitluni ] to solve them. The 12 V SLA battery was being replaced with a 20 V Li-Ion pack from a power tool. A 3d printed adapter was enlisted to break out the power pins on the pack. The excessive voltage was handled with a DC-to-DC converter tha

Like artificial intelligence, speech synthesis was one of those applications that promised to revolutionize computing in the 1980s, only to fizzle out after people realized that a robotic voice reading out predefined sentences was not actually that useful. Nevertheless, computer manufacturers didn’t want to miss out on the hype and speech synthesizers became a relatively common add-on for a typical home computer. Those add-ons were usually built around a custom voice-synthesis chip. If that chip fails, you’re out of luck: many were made in limited quantities by small companies and are impossible to find today. So if you’ve got a Tandy TRS-80 Voice Synthesizer with a dodgy SC-01-A chip, you’ll definitely want to check out [Michael Wessel]’s Talker/80 project . It’s a plug-in module for the TRS-80 that’s software compatible with the original Voice Synthesizer, but built from modern components. Synthesis is still performed by a custom IC, but now it’s using the more common Epson S1V3012

When Johnny Cash wrote “Ring of Fire”, he was talking about love. But when an unnamed follower of [TheBackyardScientist] took it literally and suggested making actual rings of fire — underwater —  they rose to the challenge as you can see in the video below the break . Of course there are several ingredients to underwater fire rings. First you need water, and a pool clearly does the job in this video. Second, you need flammable rings of gas. [TheBackyardScientist] decided to build a machine to create the gas rings, and it’s quite interesting to see them go through several iterations before settling on a voice coil based poppet valve design. We must say that it works absolutely swimmingly. Lastly there needs to be fire. And for fire, you need something flammable, and something shocking. Forty thousands volts light up a spark plug, even underwater. The fuel is provided by what appears to be compressed air and acetylene but we’re not 100% sure. We are sure that it goes  bang! quite s