With the advancements in quadrotor parts and technology over the years, it’s become possible to make just about anything fly if you can strap some high-speed rotors to it. Introducing the first edible quadrotor!
[Michael] enjoys building and flying quadrotors. His girlfriend enjoys baking and making chocolates. One day she had a crazy idea — what if they made a quadrotor together, combining their unique skill sets? [Michael] was a bit skeptical at first. After all, chocolate doesn’t really compare to aluminum or carbon for a frame material… and chocolate melts at room temperature. Regardless — they were curious enough to try it out and see for sure.
First they built a wooden prototype and then created a silicone mold from it. Using Styrofoam and metal spacers for the electronics mounts they filled the mold with chocolate and let it set. A bit of assembly later and they had a chocolate quadrotor. It flies too.
Continue reading “Chocolate Quadrotor Proves You Can Make Anything Fly”
Inverted Quadcopter? That generally means a crash is soon to follow. Not so for a new crop of quadcopter fliers. These new quadcopters are capable of sustained inverted flight. We’ve seen inverted quadcopters before here on hackaday. However, previous inverted quadcopters always used collective pitch to control the thrust produced by the blades. Collective pitch on a quadcopter is much simpler than it is on the main rotor of a traditional helicopter. R/C and full-scale helicopters mix collective and cyclic pitch to articulate the main rotor blades. A quadcopter only needs the collective portion, which is similar to a traditional helicopters tail rotor mechanism, or a variable pitch prop on an airplane.
These new quadcopters are using a much simpler method of flying inverted: Spin the motors backwards. Quadcopters control their flight by quickly varying the speed of rotation of each motor. Why not completely reverse the motor then? Today’s brushless outrunner motors have more than enough power to quickly reverse direction. The problem becomes one of propellers. Standard propellers are designed to create thrust in one direction only. Every quadcopter uses two clockwise rotation and two counterclockwise rotation propellers. Propellers will generate reverse thrust if they are spun backwards, however they will not be as efficient as they would when spinning the direction they were designed for. The quad fliers have found a partial solution to this problem: Remove the curve from the blade. R/C propeller blades are sold by diameter and blade pitch. The pitch is a measure of the angle of attack of the blades. R/C blades also have an airfoil style curve molded into them. Removing this curve (but not changing the pitch) has helped the problem.
This final problem is control systems. Since quadcopters already are relying on computer control for basic flight, it’s simply a matter of loading custom firmware onto your flight board to support motor rotation reversal. Speed controls also have to be capable of reverse rotation, which means new firmware as well. We’re curious to see how the quadcopter community settles on the control systems for inverted flight. The R/C helicopter community went through several iterations of control systems over the years. At one point they were using “Invert switches” which reversed controls as well as handled the collective pitch changes. As time went on, these switches fell out of favor and are now known as “Crash switches” due to the result of accidentally hitting one while flying, or before engine start.
Continue reading “Quadcopters Go Inverted by Reversing Their Motors”
In recent years, quadrotors have exploded in popularity. They’ve become cheap, durable, and can do some really impressive things, but are they the most efficient design? The University of Queensland doesn’t think so.
Helicopters are still much more efficient and powerful due to their one big rotor, and with the swashplate mechanism, perhaps even more maneuverable — after all did you see our recent post on collective pitch thrust vectoring? And that was a plane! A few quick searches of helicopter tricks and we think you’ll agree.
The new design, which is tentatively called the Y4, or maybe a “Triquad” is still a quadrotor, but it’s been jumbled up a bit, taking the best of both worlds. It has a main prop with a swashplate mechanism, and three smaller rotors fixed at 45 degree angles, that provide the counter torque — It’s kind of like a helicopter with three tails.
Regarding efficiency, the researchers expect this design could achieve an overall increase of about 25% in performance, compared to that of a standard quadrotor. So, they decided to test it and built a quad and a Y4 as similar as possible — the same size, mass, batteries, arms, and controller board. The results? The Y4 had an increased run time of 15%! They think the design could very well make the 25% mark, because in this test study, the Y4 was designed to meet the specifications of the quad, whereas a more refined Y4 without those limitations could perhaps perform even better.
Unfortunately there’s no video we can find, but if you stick around after the break we have a great diagram of how (and why) this design works!
Continue reading “Should all Quadrotors Look like This?”
[Oscar] has been busy lately building DIY mini quadcopters. We saw his controller design earlier in the month. Back then he was using it with his walking robot designs. Now [Oscar] has posted up some information on his quadcopter work. Even though [Oscar] is new to mini quads, he began by designing his own frame. He started his frame design by using a cut down version of the well-known 949 frame. [Oscar] chose polystyrene for his motor mounts, which turned out to be the downfall of the frame. Polystyrene proved to be much too flimsy to handle the vibrations of the motors and props. The vibrations were transmitted to the accelerometers, which resulted in a model that was very hard to control. You can see this in the first video after the break.
For his second attempt, [Oscar] started with a proven design from HobbyKing. HobbyKing’s fiberglass mini quadcopter frame is sturdy, but heavy, and expensive to replace (If the parts are even in stock). The frame did work though, so he used it as a starting point for his second DIY frame. The new frame is based upon fiberglass shafts. [Oscar] used hot glue to join the shafts to the motor mounts. Each joint was wrapped in string, which was then coated with hot glue. We’d suggest thin cyanoacrylate glue in the future for these types of joints. Only a few drops of CA soaks up into the string, creating an extremely light and strong joint. [Oscar’s] frame ended up at about half the weight of the HobbyKing frame, but was stiff enough for a successful flight test, as can be seen in the second video after the break.
Continue reading “DIY Mini Quadcopter Frame is Light and Strong”
[FlorianH] has all kinds of new features to show off with this generation of his quadcopter project. Just about everything has seen an upgrade or some other kind of tweak since we looked in on the last version of the aircraft.
You’ll find some outdoor flight demo clips after the break. Right off the bat we’re impressed at the rock solid stability of the quadrotor while in flight. Even indoors the last version had a hint of a wobble as the control loop calculated stabilization. Here he borrowed some code from the open source Aeroquad project which helps account for this improvement. But the hardware choices lend a hand too. He moved from an ATmega32 up to an STM32F405RG processor. That’s an ARM chip which he programs using one of STM’s Discovery boards. The motors have all been upgraded as well (if you listen in the demo videos for both models you can hear a difference) and he redesigned the frame, which combines carbon tube with 3D printed parts to keep it light yet strong. The upgrade is every bit as impressive as the original build!
Continue reading “[FlorianH] shows off MinimaBL, the next generation of his quadcopter project”
If you’ve been trying to decide between building an autonomous quadcopter or a fixed wing UAV, you may not have to choose anymore. [Team ATMOS] from Tu Delft University in the Netherlands, has developed a UAV that can autonomously transition from quadcopter flight to that of a fixed-wing aircraft. Although the world has seen several successful examples of transitioning-flight or VTOL aircraft, team [ATMOS] claims to have made the first autonomous transition of this type of craft.
This UAV was featured in their school newspaper, which provides a write-up about the work that went into creating this hybrid UAV. When you’re done with that, be sure to check out the two videos after the break. The first shows the [ATMOS] taking off vertically and flying off as a flying-wing fixed aircraft. The second video shows this and other UAVs in the [DARPA] competition that it was designed for. Fast forward to 2:24 to see this aircraft do a fly-by.
Thanks for the tip [Dirk]!
In case quadrocopters aren’t cool enough, here’s an orchestrated quadrotor light show that was shown at the Cannes Lions International Festival of Creativity this last week. With 16 quadrotors and a few can lights, it’s a light show not to be missed.
This quadrotor show was created by a collaboration between KMel robotics and Marshmallow Laser Feast. The guys behind KMel are the same brilliant minds behind this nanocopter swarm that can play the [James Bond] theme. For this light show, the guys at KMel Robotics used a Vicon motion capture system to coordinate the flock of quadrotors, as seen in this picture.
With a servo-controlled mirror on the bottom of each quatrotor, each vehicle in the fleet is able to reflect beams of light around the stage and into the audience. Now it’s only a matter of time until a setup like this is used for a showing of Laser Floyd.
Tip ‘o the hat to [cesar] for sending this one in. Via IEEE Spectrum.
Edit: They’re not can lights. After watching in 1080p, [Impulse405] is pretty confident they’re High End studio spots or a wash with a tight focus. Thanks for keeping us honest, [Impulse405]!