An All-Electric Plane Takes To The Skies

With climate protests and airline strikes occurring around the world, there is more awareness than ever before for the necessity of environmental sustainability. More importantly, there is more discussion around the immense carbon footprint left by the airline industry, perhaps one of the largest contributors to climate change worldwide.

The Slovenian-based Pipistrel ALPHA Electro is one of the leading electric planes today, with bragging rights as the world’s first mass-produced electric aircraft. While NASA may have announced their X-57 Maxwell, the plane is still undergoing testing for its first planned flight in 2020. The ALPHA Electro, marketed as a trainer plane for flight students and recreational flyers, features a 34’6″ wingspan and low running costs.

The two-person flyer is equipped with a 60 kW electric motor, with a cruising speed of about 157 km/hr. A 21 kW battery provides the plane with enough energy for a 55 minute flight, with a half hour reserve, and takes about an hour to charge back up. An additional perk of flying an electric plane is the low noise and zero CO2 emissions, which allows the flights to take place near large cities with exhaust and noise emission standards.

With airplanes, a majority of the fuel is used for takeoff and landing, making short haul flights particularly troublesome – compare 107 lbs CO2 flying from New York to Boston versus 62 lbs CO2 driving. While refraining from frequent flights is still the best idea for reducing your carbon footprint, we’re hopefully headed towards more environmentally-friendly options for air travel.

Check out the ALPHA Electro’s teaser video below.

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Wiping Your Windscreen To The Beat

Nothing spoils your mood quite like your windscreen wipers not feeling it when the beat drops. Every major car manufacturer is focused on trying to build the electric self driving vehicle for the masses, yet ignoring this very real problem. Well [Ian Charnas] is taking charge, and has successfully slaved his car’s wipers to beat of its stereo.

Starting with the basics, [Ian] first needed to control the speed of the wiper motor. This was done using a custom power supply adapted from another project. The brain of the system is a Raspberry Pi 3B+ which runs a phase locked loop algorithm to sync the music and the motor. Detecting the beat turned out to be the most difficult part of the project, and from the research [Ian] did, there is no standard solution. He ended up settling on “madmom“, a Python audio and music signal processing library, which runs a neural net to detect the beat in real time. The Raspi sends the required PWM and Enable signals to an Arduino over serial, which in turn controls the power supply. The entire system was neatly integrated in the car, with a switch in the dash that connects the motor to the new power supply on demand, to allow the wipers to still be used normally (and safely).

[Ian] filed a provisional patent application for the idea, and will be putting it on auction on eBay soon, with the hope that some major car manufacturer would be interested. For older cars, you can shove an Arduino into the stereo, or do a super cheap bluetooth upgrade. Check out the video after the break. Continue reading “Wiping Your Windscreen To The Beat”

Student-Built Rocket Engine Packs A Punch

A group of students at Boston University recently made a successful test of a powerful rocket engine intended for 100km suborbital flights. Known as the Iron Lotus (although made out of mild steel rather than iron), this test allowed them to perfect the timing and perfect their engine design (also posted to Reddit) which they hope will eventually make them the first collegiate group to send a rocket to space.

Unlike solid rocket fuel designs, this engine is powered by liquid fuel which comes with a ton of challenges to overcome. It is a pressure-fed engine design which involves a pressurized unreactive gas forcing the propellants, in this case isopropanol and N2O, into the combustion chamber. The team used this design to produce 2,553 lb*ft of thrust during this test, which seems to be enough to make this a class P rocket motor. For scale, the highest class in use by amateurs is class S. Their test used mild steel rather than stainless to keep the costs down, but they plan to use a more durable material in the final product.

The Boston University Rocket Propulsion Group is an interesting student organization to keep an eye on. By any stretch of the imagination they are well on their way to getting their rocket design to fly into space. Be sure to check out their other projects as well, and if you’re into amateur rocketry in general there are a lot of interesting things you can do even with class A motors.

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How To Make An Electric Scooter Chain Sprocket With Nothing But Hand Tools

Sometimes, mechanical parts can be supremely expensive, or totally unavailable. In those cases, there’s just one option — make it yourself. It was this very situation in which I found myself. My electric scooter had been ever so slightly bested by a faster competitor, and I needed redemption. A gearing change would do the trick, but alas, the chain sprocket I needed simply did not exist from the usual online classifieds.

Thus, I grabbed the only tools I had, busied myself with my task. This is a build that should be replicable by anyone comfortable using a printer, power drill, and rotary tool. Let’s get to work!

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Solar Powered Weeding Tractor Uses Manual Labour

You might not have realised this, but there’s a group of hackers out there without whom you wouldn’t be able to put food on the table. They hack under the blazing sun and pouring rain, and have been doing it for thousands of years. Known more commonly as farmers, their creative problem solving skills with whatever is lying around can be absolutely jaw dropping. [Andrew Mans] is one such individual. He built a solar powered weeding tractor that uses human labour to do the actual weeding.

We’ll be honest, this made us go “Wait, what?” for a few seconds, until the ingenuity of it all sank in. Crawling at a snails pace across the onion fields at Mans Organics, the contraption allows 3 workers to lie comfortably on their stomachs in a shaded tent, while pulling weeds that grow too close to the crop for conventional mechanised weeding methods. While this might seem like a slightly crappy job at first glance, there are definitely worse jobs a farm (or in an office) and actually looks quite relaxing. While the picking could of course be automated, this is no small task, especially when your business is food production, not robotics.

Power is provided from four 250 W solar panels on the roof, which charge a bank of deep cycle batteries and the drive train. A pure sine wave converter provides power to a 240 V motor driver which turns it back into DC to run the drive motor. [Andrew] admits this back and forth voltage conversion is overcomplicated and inefficient but it’s the sort of thing that quickly happens when you hack a hacked design. The axle and 5-speed gearbox was salvaged from an old 3 ton truck and is mounted vertically to save space. The hydraulic steering is controlled by one of the human weed pickers, who just makes small course corrections as required.

We love the weird combo of old and new in this hack. Check out the machine in action and detailed walk-around after the break. Continue reading “Solar Powered Weeding Tractor Uses Manual Labour”

How To Build The Strongest Arches

When it comes to architectural features, there are probably not many as quintessentially memorable as arches. From the simplicity of the curved structure to the seemingly impossible task of a supposedly collapsable shape supporting so much weight in mid-air, they’ve naturally fascinated architects for generations.

For civil engineers, learning to calculate the forces acting on an arch, the material strength and properties, and the weight distribution across several arches may be familiar, but for anyone with only a basic physics and CAD background, it’s easy to take arches for granted. After all, they grace the Roman aqueducts, the Great Wall of China, and are even present in nature at Arches National Park. We see them in cathedrals, mosques, gateways, and even memorialized in the case of the St. Louis Gateway Arch. Even the circular construction of watch towers and wells, as well as our own rib cages, are due to the properties of arches.

But what really goes into constructing a strong arch? Continue reading “How To Build The Strongest Arches”

Military Gliders Are Making A Comeback, This Time In Unmanned Form

Sun Tzu said, “The line between disorder and order lies in logistics.” This is as true in the modern world as it was 2500 years ago, and logistics have helped win and lose many wars and battles over the centuries. To this end, Logistical Gliders Inc. is developing one-time use, unmanned delivery gliders, for the US Military.

Reminiscent of the military gliders used in WW2, the gliders are designed to be dropped from a variety of aircraft, glide for up to 70 miles and deliver supplies to troops in the field. Specifically intended to be cheap enough to be abandoned after use, the gliders are constructed from plywood, a few aluminum parts for reinforcement and injection molded wing panels. There are two versions of the glider, both with huge payloads. The LG-1K, with a payload capacity of 700 lbs/320 kg and the larger LG-2K, with a payload capacity of 1,600 lbs/725 kg. Wings are folded parallel to the fuselage during transport and then open after release with the help of gas springs. The glider can either do a belly landing in an open area or deploy a parachute from the tail at low altitude to land on the crushable nose.

Gliders like these could be used to deliver supplies after natural disasters, or to remote locations where road travel is difficult or impossible while reducing the flight time required for conventional aircraft. Powered UAVs could even be used to carry/tow a glider to the required release point and then return much lighter and smaller, reducing the required fuel or batteries.

Drones are already used to deliver medical supplies in Rwanda and Ghana, and it’s possible to build your own autonomous unmanned glider. Check out the video after the break to see the big boys in action. Continue reading “Military Gliders Are Making A Comeback, This Time In Unmanned Form”