If you are a watcher of the world of drones, or multirotors, you may have a fixed idea of what one of these aircraft looks like in your mind. There will be a central pod containing batteries and avionics, with a set of arms radiating from it, each of which will have a motor and a propeller on its end. You are almost certainly picturing a four-rotor design, such as the extremely popular DJI Phantom series of craft.
Of course, four-rotor designs are just one of many possible configurations of a multirotor. You will commonly see octocopters, but sometimes we’ve brought you craft that really put the “multi” in “multirotor”. If the computer can physically control a given even number of motors, within reason, it can be flown.
There is one type of multirotor you don’t see very often though, the trirotor. Three propellers on a drone is a rare sight, and it’s something we find surprising because it’s a configuration that can have some surprising benefits. To think about why, it’s worth taking a look at some of the characteristics of a three-rotor machine’s flight.
This week I was approached with a question. Why don’t passenger aircraft have emergency parachutes? Whole plane emergency parachutes are available for light aircraft, and have been used to great effect in many light aircraft engine failures and accidents.
But the truth is that while parachutes may be effective for light aircraft, they don’t scale. There are a series of great answers on Quora which run the numbers of the size a parachute would need to be for a full size passenger jet. I recommend reading the full thread, but suffice it to say a ballpark estimate would require a million square feet (92903 square meters) of material. This clearly isn’t very feasible, and the added weight and complexity would no doubt bring its own risks.
While some of you may have been to see the new Star Wars movie, you might be sad that everything happened a long time ago in a galaxy far away. But there’s a group of RC enthusiasts called [Flite Test] who are trying to bring at least a little bit of that fantasy into real life. They’ve created a truck-sized Star Destroyer that actually flies. It looks kind of terrifying, too.
While it’s not as big as a “real” Star Destroyer, it’s certainly one of the biggest we’ve ever seen in real life. Built out of foam, this monstrosity is 15 feet long and powered by two huge electric motors and a large lithium polymer battery. Of course they didn’t start out by building this huge flying spaceship; they created a smaller model as proof-of-concept and flew that one around for a while to make sure everything was shipshape. While it’s exciting to see the small model in flight, it’s another thing to see the 15-foot version swooping around.
We’re sad to report that the Star Destroyer did meet a similar fate as the one that Rey was scavenging at the beginning of the movie (spoilers: it crashed), we hope that the RC team rebuilds it so it’s space worthy again. Maybe they can even add a real-life ion drive or a few lasers to make it even more real.
This Thursday, December 10th at 5pm PST we will be hosting a live HackChat about aircraft. If it’s man-made and it files, it’s on topic! Full scale and model planes, helicopters, multicopters, gyros, blimps and gliders will be on the agenda. Our host this week will be Hackaday Community Editor [Adam Fabio] who is also the author of this well-written blog entry. In addition to being an electrical engineer, [Adam] brings 30 years of experience as a Radio Control model enthusiast. Over the years he’s worked as a professional R/C Blimp Pilot for the New York Islanders Hockey team and as an aerial photographer. On the full-scale aircraft side, he’s designed radar and air traffic control software used to keep the skies safe over land and sea.
Aircraft HackChat starts Thursday at 5pm PST (here’s a timezone cheat sheet if you need it). Participating in this live chat is very simple. Those who are already part of the Hacker Channel can simply click on theTeam Messaging button. If you’re not part of the channel, just go to the hacker Channel page, scroll to the bottom of the “TEAM” list in the left sidebar and click “Request to join this project”.
HackChat takes place in the Hacker Channel every few weeks and is a friendly place to talk about engineering and the projects you’re working on.
The design goals [tlandford] has set are relatively simple for a bush plane, but building a plane that can fly 200km with a 6kg payload and return to base is a challenge that isn’t usually taken up by RC enthusiasts. For this project, [tlandford] is using an entirely 3D printed airframe, with living hinges printed right into the control surfaces. That in itself is pushing the limits of amateur airframes, but [tlandford] isn’t stopping there.
This UAV system will be completely automated, with a single ground control system taking care of controlling a swarm of planes, pointing a tracking antenna, and connecting to the Internet for observation or control from anywhere in the world.
The project that has seen a lot of improvement since it was entered in last year’s Hackaday Prize. The addition of a completely 3D printed airframe is a big one, and replacing the RVJet with something that looks a bit more like a glider should increase the loiter times over the target. There’s a video of the Icarus flying available below. If you also have a UAV project entered in The Hackaday Prize, there is now one obvious choice of what music you should use.
Armed with a variety of 3D printing techniques and years of model-building experience, [Steve] is taking the lid off a number of previously undocumented techniques, many of which are especially relevant to the model-builder equipped with a 3D printer in the workshop.
As he continues his video log, [Steve] takes you through each detail, evaluating the quality of both his tools and techniques. How does a Makerbot, a Formlabs, and a Shapeways print stand up against being used in the target application? [Steve] evaluates a number of his turbine prints with a rigorous variable-controlled test setup.
How can we predict the plane’s center-of-gravity before committing to a physical design? [Steve] discusses related design decisions with an in-depth exploration of his CAD design, modeled down to the battery-pack wires. Though he’s not entirely finished, [Steve’s] work serves as a great chance to “dive into the mind of the engineer,” a rare opportunity when we usually discover a project after it’s been sealed from the outside.
3D printing functional parts with hobbyist-grade printers is still a rare sight, though we’ve seen a few pleasant and surprisingly practical components. With some tips from [Steve], we may complete this video journey with a few techniques that bump us out of the “novelty” realm and into a space where we too can start reliably printing functional parts. We’re looking forward to seeing the maiden voyage.
While you’re trying to come up with an idea for your next project this guy’s been building his own helicopter from whatever parts he can find. He’s just one of the aeronautical hackers featured in a story in the Daily Mail. The article’s narrative leaves us with many questions, but there’s enough info to make it worth a look.
In addition to the heli seen above there are also a couple of airplane builds to gawk at. Africa has already produced a couple of very ingenious hacks like [William Kamkwamba’s] projects which improved his village infrastructure. He gained enough notice from his work to land a scholarship to continue his education and that opportunity has also been afforded the creators of these aircraft.
At first we figured this helicopter project was possible because of lack of air traffic regulation in this part of the world. That’s not the case as [Onesmus Mwangi] — who makes his living as a farmhand — has been forbidden to fly the craft by local police. There may be another opportunity for him to fly later in life. He’s received funding to study aircraft maintenance abroad.+
Unfortunately we couldn’t find any video of this thing in action. If that’s unacceptable to you try getting your fix from this human-sized octocopter.