A Practical Electric Motorcycle, Made From A Motorcycling Classic

March 28, 2021 by Jenny List 26 Comments

If you were to try to name the vehicle that brought transport to the world’s masses, where might you start? The Ford Model T perhaps, or maybe the VW Beetle? If this was the direction you took, then we’re sorry to say you aren’t even close. The answer lies in Soichiro Honda’s Dream and its descendants, small cheap and reliable motorcycles that have been manufactured in their many millions in some form continuously for over seven decades, and which have been sold in every country in the world that has any form of road. They may be unglamorous, but if you had to pick a bike to circumnavigate the globe they can be fixed by a local mechanic anywhere on the planet. That little horizontal single-cylinder engine may be reliable though, but it’s hardly green. [David Budiatmaja] has fixed that, by transforming an elderly Honda C70 into an electric motorcycle worthy of a 21st-century city (Indonesian, Google Translate link).

The conversion appears to have achieved wide coverage in the Indonesian motoring press, and there’s more about it in the video we’ve placed below the break (Indonesian, you may have to enable subtitle translation). The C70 has been stripped of its fairing, engine, and gearbox, and a wheel motor has been laced into the rear rim. There are three battery packs made from surplus 18650 cells, and an ammo can top box containing most of the electrical wiring. Driven at 72V, it gives a modest top speed that isn’t exactly fast but isn’t too bad on a city bike. A set of trail bike bars replaces the stock ones, and something of a cosmetic makeover has given it a tougher image than your local pizza delivery bike. If it didn’t still sport the C70’s somewhat archaic front forks, it might be easy to mistake it for something else entirely.

If wheel motor motorcycle conversions interest you, this isn’t the first one we’ve brought you.

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Building The Dolphin Emulator In Ubuntu On A Nintendo Switch

March 28, 2021 by Zach Zeman No comments

[LOE TECH] has made a habit of trying out various emulation methods on his Nintendo Switch and recording the results for our benefit. Of that testing, some of the best performance he’s seen makes use of the Dolphin emulator running in Ubuntu Linux, and he has made a tutorial video documenting how to build the project, as well as how to make some performance tweaks to get the most out of the mod.

We love seeing Linux run on basically anything with a processor. It’s a classic hack at this point. Nintendo has traditionally kept its consoles fairly locked down, though, even in the face of some truly impressive efforts; so it’s always a treat to see the open-source OS run relatively smoothly on the console. This Ubuntu install is based on NVIDIA’s Linux for Tegra (L4T) package, which affords some performance gains over Android installations on the same hardware. As we’ve seen with those Android hacks, however, this software mod also makes use of the Switchroot project and, of course, it only works with specific, unpatched hardware. But if you’ve won the serial number lottery and you’re willing to risk your beloved console, [LOE TECH] also has a video detailing the process he used to get Ubuntu up and running.

Check out the video below for a medley of Gamecube game test runs. Some appear to run great, and others, well… not so much. But we truly appreciate how he doesn’t edit out the games that stutter and lag. This way, we get a more realistic, more comprehensive overview of unofficial emulation performance on the Switch. Plus, it’s almost fun to watch racing games go by in slow motion; almost, that is, if we couldn’t empathize with how frustrating it must have been to play.

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Putting Your Time In

March 27, 2021 by Elliot Williams 28 Comments

I was absolutely struck by a hack this week — [Adam Bäckström]’s amazing robot arm built with modified hobby servos. Basically, he’s taken apart and re-built some affordable off-the-shelf servo motors, and like the 6-Million-Dollar Man, he’s rebuilt them better, stronger, faster. OK, and smoother. We have the technology.

The results are undeniably fantastic, and enable the experienced hacker to get champagne robot motion control on a grape-juice budget by employing some heavy control theory, and redundant sensors to overcome geartrain backlash, which is the devil of cheap servos. But this didn’t come out of nowhere. In his writeup, [Adam] starts off with “You could say this project started when I ordered six endless servos in middle school, more than 15 years ago.” And it shows.

Go check out this video of his first version of the modified servos, from a six-axis arm he built in 2009(!). He’s built in analog position sensors in the motors, which lets him control the speed and makes it work better than any other hobby servo arm you’ve ever seen, but there’s still visible backlash in the gears. A mere twelve years later, he’s got magnetic encoders on the output and a fast inner loop compensates for the backlash. The result is that the current arm moves faster and smoother, while retaining accuracy.

Twelve years. I assume that [Adam] has had some other projects on his plate as well, but that’s a long term project by any account. I’m stoked to see his work, not the least because it should help a lot of others who are ready to step up their desktop servo-arm projects. But the real take-home lesson here is that if you’ve got a tough problem that you’re hacking on, you don’t have to get it done this weekend. You don’t have to get it done next weekend either. Keep hammering on it as long as you need, but keep on hammering. When you get it done, the results will be all the better for the long, slow, brewing time. What’s the longest project that you’ve ever worked on?

Ask Hackaday: How Do You Prepare?

March 24, 2021 by Jonathan Bennett 140 Comments

Last month, large parts of the southern United States experienced their coldest temperatures since the 1899 Blizzard. Some of us set new all-time lows, and I was right in the middle of the middle of it here in Southwestern Oklahoma. Since many houses in Texas and Oklahoma are heated with electricity, the power grids struggled to keep up with the demand. Cities in Oklahoma experienced some short-term rolling blackouts and large patches of the Texas grid were without power for several days. No juice, no heat.

In places where the power was out for an extended period of time, the water supply was potentially contaminated, and a boil order was in effect. Of course, this only works when the gas and power are on. In some places, the store shelves were empty, a result of panic buying combined with perishables spoiling without the power to keep them cold. For some, food and drinkable water was temporarily hard to come by.

There have been other problems, too. Houses in the south aren’t built for the extreme cold, and many have experienced frozen pipes, temporarily shutting off their water supply. In some cases, those frozen pipes break open, flooding the house once the water starts flowing again. For instance, here’s an eye-witness account of the carnage from The 8-bit Guy, who lives at ground zero in the DFW area.
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How The LIGO Observatory Detects Gravitational Waves

March 24, 2021 by Lewin Day 43 Comments

Gravity is one of the more obvious forces in the universe, generally regarded as easily noticeable by the way apples fall from trees. However, the underlying mechanisms behind gravity are inordinately complex, and the subject of much study to this day.

A major component of this study is around the concept of gravitational waves. First posited by Henri Poincaré in 1905, and later a major component of Einstein’s general theory of relativity, they’re a phenomena hunted for by generations of physicists ever since. For the team at the Laser Interferometer Gravitational-wave Observatory, or LIGO, finding direct evidence of gravitational waves is all in a day’s work.

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Hey Google, Is My Heart Still Beating?

March 23, 2021 by Tom Nardi 18 Comments

University of Washington researchers studying the potential medical use of smart speakers such as Amazon’s Echo and Google’s Nest have recently released a paper detailing their experiments with non-contact acoustic heartbeat detection. Thanks to their sensitive microphone arrays, normally used to help localize voice commands from the user, the team proposes these affordable and increasingly popular smart home gadgets could lead a double life as unobtrusive life sign monitors. The paper goes so far as to say that even with multiple people in the room, their technique can be used to monitor the heart and respiratory rate of a specific target individual.

Those are some bold claims, but they aren’t without precedent. Previous studies performed at UW in 2019 demonstrated how smart speaker technology could be used to detect cardiac arrest and monitor infant breathing. This latest paper could be seen as the culmination of those earlier experiments: a single piece of software that could not just monitor the vitals of nearby patients, but actually detect a medical emergency. The lifesaving potential of such a program, especially for the very young and elderly, would be incredible.

So when will you be able to install a heart monitor skill on the cheap Echo Dot you picked up on Prime Day? Well, as is often the case with this kind of research, putting the technique to work in the real-world isn’t nearly as easy as in the laboratory. While the concept is promising and is more than worthy of further research, it may be some time before our lowly smart speakers are capable of Star Trek style life-sign detection.

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Bringing Some Coulter To The Bench: Measuring Tiny Particles With Nanopore Sensing

March 22, 2021 by Adam Zeloof 6 Comments

We’ve all been there: you’re sitting at your bench, with a beaker full of some conductive fluid with a bunch of tiny particles suspended in it, and you want to measure the sizes of each particle.

Okay, maybe this isn’t a shared experience we’ve all had, but It’s at least an ordeal Hackaday alum [Nava Whiteford] has been through, and he was able to carry out the measurements in question using a neat apparatus known as a Coulter counter.

Imagine a container full of a conductive fluid. If you place an electrode at each end, the fluid will carry a current. Now, drop an insulating divider in the middle of the container, and the current will stop flowing. Finally, poke a small hole (or nanopore) in the divider. Huzzah! The current is flowing again… but how does this let us measure particle sizes? Well, now think about a tiny particle moving through the hole in the divider. As the particle passes through, the hole will be partially blocked, and the current flow will be partially interrupted. It turns out, the resulting dip in current is proportional to the volume of the particle — a fun property known as the Coulter principle.

[Nava] built a great demo of the system with a macropore in place of the nanopore. The pore in question was a hole melted into a bottle cap, which was suspended in a beaker by two toothpicks. [Nava] used small chips of Acrylic as the particles to be measured, which they pipetted into the solution of KCl. They then passed a current through the solution and used an oscilloscope to sense the interruptions. Be sure to check out their write up for a video of the system in action!

Of course, this technique has a much wider range of applications than measuring little bits of plastic — obtaining blood cell counts, for one. We’ve seen particle counters for use in the air before, but it’s great to see that there’s a way to measure particles in an aqueous solution — you know, in case we ever find ourselves in such a situation.