GE’s Engine To Reignite Civil Supersonic Flight

October 24, 2018 by Tom Nardi 110 Comments

On October 24th, 2003 the last Concorde touched down at Filton Airport in England, and since then commercial air travel has been stuck moving slower than the speed of sound. There were a number of reasons for retiring the Concorde, from the rising cost of fuel to bad publicity following a crash in 2000 which claimed the lives of all passengers and crew aboard. Flying on Concorde was also exceptionally expensive and only practical on certain routes, as concerns about sonic booms over land meant it had to remain subsonic unless it was flying over the ocean.

The failure of the Concorde has kept manufacturers and the civil aviation industry from investing in a new supersonic aircraft for fifteen years now. It’s a rare example of commercial technology going “backwards”; the latest and greatest airliners built today can’t achieve even half the Concorde’s top speed of 1,354 MPH (2,179 km/h). In an era where speed and performance is an obsession, commercial air travel simply hasn’t kept up with the pace of the world around it. There’s a fortune to be made for anyone who can figure out a way to offer supersonic flight for passengers and cargo without falling into the same traps that ended the Concorde program.

With the announcement that they’ve completed the initial design of their new Affinity engine, General Electric is looking to answer that call. Combining GE’s experience developing high performance fighter jet engines with the latest efficiency improvements from their civilian engines, Affinity is the first new supersonic engine designed for the civil aviation market in fifty five years. It’s not slated to fly before 2023, and likely won’t see commercial use for a few years after that, but this is an important first step in getting air travel to catch up with the rest of our modern lives.

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Building An Electric Scooter That’s Street Legal, Even In Germany

October 23, 2018 by Dan Maloney 47 Comments

Sometimes a successful project isn’t only about making sure all the electrons are in the right place at the right time, or building something that won’t collapse under its own weight. A lot of projects involve a fair amount of social engineering to be counted as a success, especially those that might result in arrest and incarceration if built as originally planned. Such projects are often referred to as “the fun ones.”

For the past few months, we’ve been following [Bitluni]’s DIY electric scooter build, which had been following the usual trajectory for these things – take a stock unpowered scooter, replace the rear wheel with a 250 W hub motor, add an ESC, battery, and throttle, and away you go. Things took a very interesting turn, however, when his street testing ran afoul of German law, which limits small electric vehicles to a yawn-inducing 6 kph. Unwilling to bore himself to death thus, [Bitluni] found a workaround: vehicles that are only assisted by an electric motor have a much more reasonable speed limit of 25 kph. So he added an Arduino with a gyro and accelerometer module and wrote a program to only power the wheel after the rider has kicked the scooter along a few times – no throttle needed. The motor stops after a bit, needing another push or two to kick it back on. A brake lever kills the motor, as does laying the scooter on its side. It’s quite a clever design, and while it might not keep the Polizei at bay, you can’t say he didn’t try.

[Bitluni] has quite a range of builds, from software-defined television to bad 3D-scanners to precision wine glass whacking. You should check out his stuff. Continue reading “Building An Electric Scooter That’s Street Legal, Even In Germany” →

DIY Arc Light Makes An Unnecessarily Powerful Bicycle Headlight

October 17, 2018 by Dan Maloney 39 Comments

Remember when tricking out a bike with a headlight meant clamping a big, chrome, bullet-shaped light to your handlebar and bolting a small generator to your front fork? Turning on the headlight meant flipping the generator into contact with the front wheel, powering the incandescent bulb for the few feet it took for the drag thus introduced to grind you to a halt. This ridiculous arc-lamp bicycle headlight is not that. Not by a long shot.

We’re used to seeing [Alex] doing all manner of improbable, and sometimes impossible, things on his popular KREOSAN YouTube channel. And we’re also used to watching his videos in Russian, which detracts not a whit from the entertainment value for Andglophones; subtitles are provided for the unadventurous, however. The electrodes for his arc light are graphite brushes from an electric streetcar, while the battery is an incredibly sketchy-looking collection of 98 18650 lithium-ion cells. A scary rat’s nest of coiled cable acts as a ballast to mitigate the effects of shorting when the arc is struck. The reflector is an old satellite TV dish covered in foil tape with the electrodes sitting in a makeshift holder where the feedhorn used to be. It’s bright, it’s noisy, it’s dangerous, and it smokes like a fiend, but we love it.

Mounting it to the front of the bike was just for fun, of course, and it works despite the janky nature of the construction. The neighbors into whose apartments the light was projected could not be reached for comment, but we assume they were as amused as we were.

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Can A Motorized Bicycle Run On Trees?

October 17, 2018 by Brian Benchoff 59 Comments

Some of the earliest automobiles weren’t powered by refined petrochemicals, but instead wood gas. This wood gas is produced by burning wood or charcoal, capturing the fumes given off, and burning those fumes again. During World War II, nearly every European country was under gasoline rations, and tens of thousands of automobiles would be converted to run on wood gas before the war’s end.

In the century or so since the first car rolled on wood gas, and after hundreds of books and studies were published on the manufacturing and development of wood gas generators and conversion of internal combustion engines, there’s one question: can someone convert a moped to run on wood gas? [NightHawkinLight] finally answered that question.

The basic setup for this experiment is a tiny, tiny internal combustion engine attached to a bicycle. Add a gas tank, and you have a moped, no problem. But this is meant to run on firewood, and for that you need a wood gas generator. This means [NightHawkinLight] will need to burn wood without a whole lot of oxygen, similar to how you make charcoal. There is, apparently, the perfect device to do this, and it’ll fit on the back of a bike. It’s a bee smoker, that thing bee keepers use to calm down a hive of honeybees.

The bee smoker generates the wood gas, which is filtered and cooled in a gallon paint bucket filled with cedar chips. The output from this filter is fed right into where the air filter for the internal combustion engine should be, with an added valve to put more air into the carburetor.

So, with that setup, does the weird bike motorcycle wood gas thing turn over? Yes. The engine idled for a few seconds without producing any useful power. That’s alright, though, because this is just a proof of concept and work in progress. Getting this thing to run and be a useful mode of transportation will require a much larger wood gas generator, but right now [NightHawkinLight] knows his engine can run on wood gas.

Cheating The Perfect Wheelie With Sensors And Servos

September 24, 2018 by Dan Maloney 8 Comments

Everyone remembers popping their first wheelie on a bike. It’s an exhilarating moment when you figure out just the right mechanics to get balanced over the rear axle for a few glorious seconds of being the coolest kid on the block. Then gravity takes over, and you either learn how to dismount the bike over the rear wheel, or more likely end up looking at the sky wondering how you got on the ground.

Had only this wheelie cheating device been available way back when, many of us could have avoided that ignominious fate. [Tom Stanton]’s quest for the perfect wheelie led him to the design, which is actually pretty simple. The basic idea is to apply the brakes automatically when the bike reaches the critical angle beyond which one dares not go. The brakes slow the bike, the front wheel comes down, and the brakes release to allow you to continue pumping along with the wheelie. The angle is read by an accelerometer hooked to an Arduino, and the rear brake lever is pulled by a hobby servo. We honestly thought the servo would have nowhere near the torque needed, but in fact it did a fine job. As with most of [Tom]’s build his design process had a lot of fits and starts, but that’s all part of the learning. Was it worth it? We’ll let [Tom] discuss that in the video, but suffice it to say that he never hit the pavement in his field testing, although he appeared to be wheelie-proficient going into the project.

Still, it was an interesting build, and begs the question of how the system could be improved. Might there be some clues in this self-balancing motorized unicycle?

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Open Source Paramotor Using Quadcopter Tech

September 17, 2018 by Tom Nardi 24 Comments

Have you ever dreamed of flying, but lack the funds to buy your own airplane, the time to learn, or the whole hangar and airstrip thing? The answer might be in a class of ultralight aircraft called powered paragliders, which consist of a soft inflatable wing and a motor on your back. As you may have guessed, the motor is known as a paramotor, and it’s probably one of the simplest powered aircraft in existence. Usually little more than big propeller, a handheld throttle, and a gas engine.

But not always. The OpenPPG project aims to create a low-cost paramotor with electronics and motors intended for heavyweight multicopters. It provides thrust comparable to gas paramotors for 20 to 40 minutes of flight time, all while being cheaper and easier to maintain. The whole project is open source, so if you don’t want to buy one of their kits or assembled versions, you’re free to use and remix the design into a personal aircraft of your own creation.

It’s still going to cost for a few thousand USD to get a complete paraglider going, but at least you won’t need to pay hangar fees. Thanks to the design which utilizes carbon fiber plates and some clever hinges, the whole thing folds up into a easier to transport and store shape than traditional paramotors with one large propeller. Plus it doesn’t hurt that it looks a lot cooler.

Not only are the motors and speed controls borrowed from the world of quadcopters, but so is the physical layout. A traditional paramotor suffers from a torque issue, as the big propeller wants to twist the motor (and the human daring enough to strap it to his or her back) in the opposite direction. This effect is compensated for in traditional gas-powered paramotor by doing things like mounting the motor at an angle to produce an offset thrust. But like a quadcopter the OpenPPG uses counter-rotating propellers which counteract each others thrust, removing the torque placed on the pilot and simplifying design of the paraglider as a whole.

If you still insist on the fixed-wing experience, you could always get some foam board and hope for the best.

[Thanks to Luke for the tip.]

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Adding Upgrades To A Stock Motorcycle

September 11, 2018 by Bryan Cockfield 28 Comments

In today’s world of over-the-air firmware upgrades in everything from cars to phones to refrigerators, it’s common for manufacturers of various things to lock out features in software and force you to pay for the upgrades. Even if the hardware is the same across all the models, you can still be on the hook if you want to unlock anything extra. And, it seems as though Suzuki might be following this trend as well, as [Sebastian] found out when he opened up his 2011 Vstrom motorcycle.

The main feature that was lacking on this bike was a gear indicator. Even though all the hardware was available in the gearbox, and the ECU was able to know the current gear in use, there was no indicator on the gauge cluster. By using an Arduino paired with an OBD reading tool (even motorcycles make use of OBD these days), [Sebastian] was able to wire an LED ring into the gauge cluster to show the current gear while he’s riding.

The build is very professionally done and is so well blended into the gauge cluster that even we had a hard time spotting it at first. While this feature might require some additional lighting on the gauge cluster for Suzuki to be able to offer this feature, we have seen other “missing” features in devices that could be unlocked with a laughably small amount of effort.

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