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Hackaday Links: February 5, 2023

February 5, 2023 by 33 Comments

Well, this week’s Links article is likely to prove a bit on the spicy side, thanks in no small part to the Chinese balloon that spent the better part of the week meandering across the United States. Putting aside the politics of the whole thing — which we’ll admit is hard to do, given the state of the world today — there are some interesting technical aspects to this story, which the popular press has predictably ignored. Like the size of this thing — it’s enormous. This is not even remotely on the same scale as the hundreds of radiosonde-carrying balloons sent aloft every day, at least if the back-of-the-envelope math thoughtfully sent to us by [Dr_T] holds up. If the “the size of three buses” description given in most media reports is accurate, that means a diameter of about 40 meters, for a volume of 33,500 cubic meters. If it’s filled with helium — a pretty safe bet — that makes its lifting capacity something like three metric tons. So maybe it was a good idea to wait until it was off the Carolinas to shoot it down.

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Hackaday Links: January 22, 2023

January 22, 2023 by 48 Comments

The media got their collective knickers in a twist this week with the news that Wyoming is banning the sale of electric vehicles in the state. Headlines like that certainly raise eyebrows, which is the intention, of course, but even a quick glance at the proposed legislation might have revealed that the “ban” was nothing more than a non-binding resolution, making this little more than a political stunt. The bill, which would only “encourage” the phase-out of EV sales in the state by 2035, is essentially meaningless, especially since it died in committee before ever coming close to a vote. But it does present a somewhat lengthy list of the authors’ beefs with EVs, which mainly focus on the importance of the fossil fuel industry in Wyoming. It’s all pretty boneheaded, but then again, outright bans on ICE vehicle sales by some arbitrary and unrealistically soon deadline don’t seem too smart either. Couldn’t people just decide what car works best for them?

Speaking of which, a man in neighboring Colorado might have some buyer’s regret when he learned that it would take five days to fully charge his brand-new electric Hummer at home. Granted, he bought the biggest battery pack possible — 250 kWh — and is using a standard 120-volt wall outlet and the stock Hummer charging dongle, which adds one mile (1.6 km) to the vehicle’s range every hour. The owner doesn’t actually seem all that surprised by the results, nor does he seem particularly upset by it; he appears to know enough about the realities of EVs to recognize the need for a Level 2 charger. That entails extra expense, of course, both to procure the charger and to run the 240-volt circuit needed to power it, not to mention paying for the electricity. It’s a problem that will only get worse as more chargers are added to our creaky grid; we’re not sure what the solution is, but we’re pretty sure it’ll be found closer to the engineering end of the spectrum than the political end.

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Hackaday Links: December 25, 2022

December 25, 2022 by 21 Comments

Looks like it’s lights out on Mars for the InSight lander. The solar-powered lander’s last selfie, sent back in April, showed a thick layer of dust covering everything, including the large circular solar panels needed to power the craft. At the time, NASA warned that InSight would probably give up the ghost sometime before the end of the year, and it looks like InSight is sticking to that schedule. InSight sent back what might be its last picture recently, showing the SEIS seismic package deployed on the regolith alongside the failed HP3 “mole” experiment, which failed to burrow into the soil as planned. But one bad experiment does not a failed mission make — it was wildly successful at most everything it was sent there to do, including documenting the largest marsquake ever recorded. As it usually does, NASA has anthropomorphized InSight with bittersweet sentiments like “Don’t cry, I had a good life,” and we’re not quite sure how we feel about that. On the one hand, it kind of trivializes the engineering and scientific accomplishments of the mission, but then again, it seems to engage the public, so in the final rinse, it’s probably mostly harmless.

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Mazda Patents Spinning Dorito To Extend EV Range

December 16, 2022 by 44 Comments

OK, so a Wankel engine doesn’t really use a Dorito as its cylinders, but it sure looks like one. The company has announced it will offer a range extender rotary engine for the MX-30 electric “crossover” vehicle, but [CarBuzz] dug into the patent papers to find out that it has some interesting twists.

The MX-30 is an EV with a relatively small 35.5 kWh battery. Like a hybrid vehicle, the car includes a small internal combustion engine that can charge the battery. It does not, however, directly drive the wheels at any time. The Wankel has several improvements, including a secondary port that allows more air into the combustion chamber when the engine has to produce high power. But there’s a problem…

The secondary port is great when you are pushing hard, but at low speed, it produces inefficiency. To combat that, Mazda includes a valve to seal off the second port when it doesn’t make sense to open it. But that’s not the strange part. The strange part is that the engine also has its own electric assist motor that runs off the main battery.  That’s right. The battery you are charging provides some energy to operate the electric assist motor to help the engine that is charging the battery. If that makes your head spin like the Wankel’s rotor, you aren’t alone.

The assist motor can assist or retard the output shaft during the intake stroke. This can optimize the intake to the combustion chamber. Of course, this will cause odd movement in the engine’s output, but since it doesn’t drive the car, who cares? The battery isn’t going to mind if the output isn’t smooth.

The Wankel shows up in a lot of odd places. We’ve seen Wankel air compressors. Despite detractors, there have been many improvements in the design over the years.

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Hackaday Links: December 4, 2022

December 4, 2022 by 25 Comments

Well, this is embarrassing! Imagine sending a multibillion-dollar rover to an ancient lakebed on Mars only to discover after a year of poking around at the rocks that it might not actually have been a lake after all. That seems to be the impression of Jezero Crater that planetary scientists are forming after looking at the data coming back from Perseverance since it nailed the landing in what sure as heck looked like a dried-up lake, complete with a river delta system. A closer look at the sediments Perseverance has been sampling reveals a lot of the mineral olivine, which on Earth is rare near the surface because it readily reacts with water. Finding lots of olivine close below the surface of Jezero suggests that it either wasn’t all that watery once upon a time, or that what water was there was basically ice cold. The results are limited to where the rover has visited, of course, and the nice thing about having wheels is that you can go somewhere else. But if you were hoping for clear signs that Jezero was once a lake teeming with life, you might have to keep waiting.

In other space news, we have to admit to taking NASA to task a bit in the podcast a couple of weeks back for not being quite up to SpaceX’s zazzle standards with regard to instrumenting the SLS launch. Yeah, a night launch is spectacular, but not having all those internal cameras like the Falcon has just sort of left us flat. But we should have been more patient, because the images coming back from Artemis 1 are simply spectacular. We had no idea that NASA attached cameras to the solar panels of the Orion spacecraft, which act a little like selfie sticks and allow the spacecraft to be in the foreground with Earth and the Moon in the background. Seeing Earth from lunar distance again for the first time in 50 years has been a real treat, and getting our satellite in the frame at the same time is a huge bonus.

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The J1772 Hydra Helps You Charge Two EVs At Once

December 2, 2022 by 20 Comments

There are plenty of electric vehicle (EV) chargers out there that are underutilized. This is particularly common where older EVs are involved, where the cars may only be able to charge at a few kW despite the charger being capable of delivering more. [Nick Sayer] regularly found 6.6 kW chargers being used by vehicles that could only draw down 3.3 kW at his work. Thus, he built the J1772 Hydra as a nifty double-adapter to charge two cars at once.

The Hydra comes in two versions. One is a “splitter,” which is designed to be plugged into an existing J1772 AC charger. The other is a version designed for permanent installation to an AC power supply as an EV charger in its own right. Either way, both versions of the Hydra work the same way. In “shared” mode, the Hydra splits the available AC power equally between both cars connected to the charger. When one completes, the other gets full power. Alternatively, it can be set up in “sequential” mode, allowing one car to first charge, then the other. This is great when you have two cars to charge overnight and don’t want to wake up to shift the plugs around.

It’s a neat hack that could be useful if you’re running older EVs that rely on slower AC charging. We’ve seen other DIY EV chargers before, too. Expect hacking in these areas to become more commonplace as EVs grow in popularity.

This Electric Outboard Conversion Makes For A Quiet Day On The Water

November 29, 2022 by 21 Comments

Nothing beats a day on the lake in a little boat with an outboard motor putt-putting along behind you. It’s great fun, if perhaps a little noisy with all that putting going on. And maybe that oily sheen on the water in your wake is not so nice. it could be that the fish are a little annoyed with your putting, too. Come to think of it, outboard motors are a bit of a problem.

Fortunately there’s a better way, like converting an old outboard motor to electric. It comes to us by way of [Anton], who happened upon the perfect donor platform — a 5-hp outboard by Crescent, sporting a glorious 1970s color scheme and a motor housing shell perfect for modding. He started by ripping the old engine and drivetrain out of the housing to make room for the BLDC motor and its driver. The motor was a project in itself; [Anton] rewound the original stator with much thicker wire and changed the coil configuration to milk as much torque as possible out of it. What started as a 180-kv motor ended up at 77 kv with much more copper and new Hall sensors for the controller. He also put a ton of effort into waterproofing the motor with epoxy resin. With a 3D-printed prop and a streamlined fairing, the new motor looks quite at home on the outboard. In fact, the whole thing barely looks customized at all — the speed control is even right on the tiller where you’d expect it.

The video below shows the build and a test run, plus an analysis of the problems encountered, chief of which is water intrusion. But as [Anton] rightly points out, that’s easily solved by reusing the original driveshaft and mounting the motor above the waterline, like this. Still, we like the look of this, and the idea of knocking around on the water nearly silently seems wonderful.

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