From time to time it’s good to be reminded that mechanical engineering can also be art. [José Manuel Hermo Barreiro], also known as [Patelo], is a retired naval mechanic with a love for scale model engines. Using only basic tools and a lathe, he has built a non-flying hexacopter display model, each propeller turned by a tiny single cylinder motor that runs on compressed air. From the tiny components of the valve systems, the brass framed acrylic windows into the crankcases, and the persistence of vision disc on the exhaust, the attention to detail is breathtaking.
[Patelo] started the project on paper, and created a set of detailed hand-drawn blueprints to work from. Sadly a large part of the build took place during lockdown, and was not filmed, but we still get to see some work on a crankcase, connecting rod, camshaft, propellers, flywheel, and exhaust tubes. It is very clear that [Patelo] knows his way around his lathe very well, and is very creative with custom tools and jigs. The beautiful machine took approximately 1,560 hours to build, consists of 265 individually made parts held together with 362 screws.
We previously featured tiny V-12 engine that [Patelo] built around 2012. At that time he was 72 years of age, which means he should be around 80 now. We can only hope to come to emulate him one day, and that we get to see more of what comes out of his workshop. Hats off to you, sir.
Modern radio-controlled multi-rotor drone can be incredibly agile, but can only make orientation changes around the yaw axis while remaining in approximately the same position. Researchers at ETH Zurich have again built and tested multirotor with controllable motion six degrees of freedom, this time dramatically improving efficiency.
We covered a similar design from ETH Zurich previously which was hexacopter with arms with limited rotation. This new design is also a hexacopter, but with 2 coaxial motors on each rotating arm. Each arm has an increased range of rotation over the previous design, beyond 360 degrees. With the range of rotation and the very complex control system, the drone can efficiently fly in any orientation, while still being able to apply effective torque or linear force in any direction. This opens up a lot of possibilities for tasks that drones can perform, like close-up industrial inspection, using tools or pulling cables while keeping the rotors clear.
The arms do have a limited amount of rotation before winding the motor cable tight, but the control system keeps track of this and can unwind during or after movement. See the video after the break to see it in action. The complete scientific paper is not light reading, but definitely interesting. We’re looking forward to seeing if and when these type designs get used in real-world applications.
There are without a doubt a lot of drones in our future, and probably the most successful project to date is the Zipline fixed-wing drones in Rwanda and Ghana, which have made over 35000 deliveries of emergency medical supplies since 2016.
If your favorite movie is Ratatouille, now would be a good time to read a different article. Rats on the Galápagos Islands are an invasive species and eradication is underway. This is not a first for the islands, and they are fiercely protected since they are the exclusive home to some species including the distinctive tortoise from which the island derives its name and of course finches. Charles Darwin studied the finches while writing On the Origin of Species. So yeah, we want to keep this island from becoming unbalanced and not disturb the native wildlife while doing it. How do we check all these boxes? Technology! Specifically, hexacopters carrying rat poison.
The plan is simple, drive a truck to a central location, release the hounds drones and fifteen minutes later they come back after flying high above the indigenous wildlife and dropping pest control pellets. The drones save time and labor, making them a workhorse rather than a novelty. This work experience on their resume (CV) could open the door to more dirty work or more wholesome activities. Who is to say that the same drones, the exact same ones, couldn’t deliver plant seeds, or nourishing food to the dwindling species harmed by the rat population explosion.
For those who haven’t read [Ayn Rand’s] philosophical tome Atlas Shrugged, there’s a pretty cool piece of engineering stuffed in between the 100-page-long monologues. Although fictional, a character manages to harness atmospheric static electricity and convert it into kinetic energy and (spoilers!) revolutionize the world. Harnessing atmospheric static electricity isn’t just something for fanciful works of fiction, though. It’s a real-world phenomenon and it’s actually possible to build this motor.
As [Richard Feynman] showed, there is an exploitable electrical potential gradient in the atmosphere. By suspending a tall wire in the air, it is possible to obtain voltages in the tens of thousands of volts. In this particular demonstration, a hexacopter is used to suspend a wire with a set of needles on the end. The needles help facilitate the flow of electrons into the atmosphere, driving a current that spins the corona motor at the bottom of the wire.
There’s not much torque or power generated, but the proof of concept is very interesting to see. Of course, the higher you can go the more voltage is available to you, so maybe future devices such as this could exploit atmospheric electricity to go beyond a demonstration and do useful work. We’ve actually featured the motor that was used in this demonstration before, though, so if you’re curious as to how a corona motor works you should head over there.
[Robert’s] been hard at work becoming a hexacopter expert over the past two years, and he’s offered up a retrospective of his multi rotor build experience since he first clicked the “buy” button on Hobbyking. He’s come a long way from his first build, which used inexpensive carbon rods and 3D-printed parts for a frame, supported by scrap wood and hot glue. It met its end in his car; exposed to direct sunlight, the 3D-printed components melted.
The latest iteration—seen above on the right—is a complete redesign, with a laser-cut frame that dramatically reduced the overall weight and new “Donkey” motors off Hobbyking. It’s strong enough to lift a 1.6kg (3.5lbs) stuffed animal suspended from a rope! Most recently [Robert] has worked out streaming first-person video after fitting a camera to the hexacopter via a 3D-printed attachment and pairing the experience with Zeiss Cinemizer 3D glasses. He still has some bugs to work out, namely screws loosening from vibrations and adding a HUD to the display so he’ll know when the battery levels are low. You can see the poor teddy bear getting hanged along with some other videos, including the first-person video flight, after the break.
When you’re in need of some breadboarding action with your Raspberry Pi and want to make it as painless as possible you need to build your own Pi Cobbler. This is the diy version of an Adafruit product, built using a couple of pin headers, stripboard, and an IDE cable.
Perhaps this coded entry system will inspire a future project for you. It uses piezo elements to enter a code which unlocks the back door to the company. The glass door already had a series of large dots painted on it. This turns out to be a nice interface for a four button code system.
Many projects use a Raspberry Pi as a web server. But there is more than just one flavor available. [Jeremy Morgan] performed a variety of Pi server benchmarks using Nginx, Monkey, Lighttpd, and Apache. [Thanks Walter]
Online RC store Hobby King is once again encouraging people to push the limits of what quadcopters and other multirotor remote control vehicles can do. They call it the beerlift and the goal is simple: build a multirotor craft capable of carrying the greatest amount of beer (or water, everything is measured by weight).
The competition is over, but the results were spectacular. The vehicle with the largest lift capacity – pictured above – was built by [Olaf Frommann] and carried 58.7 kilograms, or nearly 128 pounds to a hover a few feet off the ground. Last year the biggest lift was a mere 47 kg with an eight-rotor craft.
It was still an impressive showing all around. The biggest lift in the 700 class – 700 mm from rotor to rotor – was done by [David Ditch] with 19.6 kg. You can check out some of the best entries below, including an amazing aerobatic quadcopter that can successfully loop carrying a cup of beer,