Hackaday Europe 2026: Half Quad, Half Blimp: Test. Fly. Survive.

July 23, 2026 by Zoe Skyforest 8 Comments

A great many drones out there, whether homebuilt or store-bought, follow the same basic format. Four motors, some kind of controller, and a lithium-polymer battery supplying the juice to keep everything in the air. It’s a format that produces a remarkably capable air vehicle, suitable for everything from high-speed camera work to urban search and rescue.

With that said, the format does have its limitations. [Suryansh Sharma] has been working on alternative designs for fancy and interesting drones that are half quadcopter and half blimp, and he came to Hackaday Europe 2026 to tell us all about it.

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A quadcopter with a clear, U-shaped shield up front and red propellers navigates between a close stand of moss-covered trees.

Echolocation For Drones

July 20, 2026 by Navarre Bartz 6 Comments

Bats are remarkable creatures, able to fly at night or inside the confines of caves without light to guide their way. A team of researchers at Worcester Polytechnic Institute (WPI) has determined how to use low power ultrasonic sensors to guide drones in obscured environments.

While radar, lidar, and GPS are all great for navigation and sensing, they can run into issues when light is obscured or can take too much power to be practical for the limited battery life of a drone. The researchers found that a dual sonar array could be used to implement a much lower power sensing system for a drone that performs well in environments that would stymie a computer vision system.

A shield placed behind the array cuts down on the sound of the propellers that would otherwise drown out the signal, and further signal analysis via a neural net separates the echoes of objects in front of the drone from the background. The prototype could navigate in various simulated environments like forests, smoke, and snow. It looks like it even got a chance to go for a flight in the actual woods. All the code and hardware designs are Open Source, so have at it!

We’ve covered mosquito-inspired drone sensors before, and if you want to get into echolocation yourself, apparently humans can learn to do it too.

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Spidery Drone Goes Near-invisible By Spinning Really, Really Fast

July 18, 2026 by Donald Papp 27 Comments

Researchers demonstrate that something interesting happens when a small drone with a spindly airframe spins at a high speed: it very nearly turns invisible. The spidery device is shown mounted in its launcher in the image above. The dark blur at the rightmost side is an outlet on the wall behind the drone, not motion blur from a moving part.

There’s not much to do about the noise, but a high-speed spin becomes nearly invisible.

It’s called the Phantom Twist, and while we’ve seen single-motor drones that spin around a central axis before, they have always incorporated a wing-like structure or cleverly leverage the magnus effect to generate lift.

There’s not a lot of detail about the Phantom Twist’s hardware design but it appears to use a downward-angled motor for lift, relying on a high-speed control system to maneuver and maintain altitude.

This does away with the need for a wing, at the cost of only being stable while rotating at a high speed. We imagine it is also a touchy design that depends greatly on being balanced just so.

A hand launcher spins the device up before releasing it for flight. The visual effect once it is up and running is pretty striking; see for yourself in the short video, embedded just below.

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A Rare Drone Common Sense Outbreak, In Denmark

July 2, 2026 by Jenny List 22 Comments

Last September, Denmark was gripped by a spate of drone sightings near airports. It’s familiar territory for Hackaday, as we reported on a similar drone panic saga at British airports back in the last decade. Back then the British police dragged their feet and hid behind secrecy laws for years to avoid admitting they overreacted, but it seems in Denmark they do things differently (Danish language, Google Translate link.).

The Danish police in Jutland have rolled back their report, and noted that a reported observation alone is not enough to confirm a drone was present. It’s not confirmed why they’ve taken this step, but we’ve been told that there’s been an effort within the drone community to identify possible aircraft flight paths which could have resulted in a false drone sighting at the times in question.

We welcome this correction, and hope that its important message travels widely. Of course it is the right thing to do for a police force to take drone reports seriously, but overreacting as the British police did is of little help. We commend the Danish police for taking this step, and we’re likely to trust any drone reports from them a little bit more in the future. If you’d like to read our plea for a sensible response at the time, it’s here.

Thanks [UAVHive] for the tip.

Custer’s Revenge: EVTOL Drone Brings Back Channel Wings

June 15, 2026 by Tyler August 7 Comments

You have to be a pretty big aviation nerd to know about [Willard Ray Custer] and his channel wing concept, but if you are, you’ll be giddy to hear about the semicircular profile of the HopFlyt Cyclone drone’s tandem wings. If you’re not quite that much of a nerd, please keep reading, because it’s a really neat concept that never — er — quite got off the ground.

[Custer]’s idea was pretty simple, and born of a shift in reference frame — he realized that only the relative wind over the wing mattered, not the airspeed of the entire aircraft. The same idea drives every blown-wing short-takeoff-and-landing (STOL) project from the DHC-7 turboprop airliner to the An-72 cargo jet: air from the engines washes over the wings, creating lift. Where [Custer] went further is that rather than blowing air over a straight wing, he wrapped the wing under the propeller in a semicircle to maximize the area of lower pressure — and thus lift — creating the “channel wing” that bears his name.

Theoretically, an aircraft with channel wings and powerful enough engines might be able to do vertical takeoffs just from the blown lift, but none of [Custer]’s prototypes demonstrated that — just excellent short-field capability. The HopFlyt drone would be the same, except that, being a tandem, it has double the channel wings of [Custer]’s more-conventional designs, and it’s also a tilt-wing to boot. In that mode, the added low-speed lift from the channel wing makes transitions easier than they otherwise would be — which isn’t anything to sneeze at, since transitioning from vertical to horizontal flight has always been the real bane of VTOL projects.

They’re claiming a reduced fuel burn of 10% in hover and transition thanks to the extra lift from the channel wings. You can see their prototype in action in the demo video embedded below. We once featured a project that went even further, blowing air across a special hollow wing for propulsion and blown lift. The easiest eVTOL project still starts with a quadcopter, though.

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Variable-Pitch Propellers For More Efficient Quadcopter

April 8, 2026 by Tyler August 20 Comments

Quadcopters tend to have very poor efficency because of their high disk loading. High disk loading– that is, how much weight each square meter of area swept by the propellers must carry–is almost unavoidable with conventinal quadcopters, which are controlled by throttling the four props. Make the propellers too big, and their inertia slows down that control loop, leading to stability problems. [rctestflight] had an idea to solve this, by borrowing a technology from the world of fixed-wing aviation: variable-pitch propellers.

In aircraft use, they are not new, dating back to the end of the first world war. They’re made for everything from the largest turboprops to the 75 kW(100 HP) Rotax 912. By varying the propeller pitch, you can keep the engine turning in its ideal RPM range but still vary thrust by taking a larger or shallower ‘bite’ out of the air with each sweep of the prop. You can probably see how this applies to the quadcopter: a well-designed pitch-change mechanism is going to be much quicker than throttling a big prop with lots of rotational inertia. That’s the theory.

To test it, [rctestflight] builds some large 3D-printed variable pitch props, hooks them up to regular drone motors via a belt drive, before going on–you guessed it–an RC test flight. To make that work, he’s got the pitch servo being driven from what should be the flight controller’s thrust output to each motor. Aside from the vibrations from imperfect balance on the 3D-printed props, it flies quite well– and much better with pitch control than trying to vary the RPMs of those heavy props. He’s even able to reverse the propeller pitch, making this perhaps the first quadcopter capable of autorotation. Well, almost, given that it lost control and came apart when he cut the throttle.

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A laptop communicating with the drone via an Arduino

Reverse-Engineering The Holy Stone H120D Drone

March 31, 2026 by Julian Scheffers 5 Comments

There are plenty of drones (and other gadgets) you can buy online that use proprietary control protocols. Of course, reverse-engineering one of these protocols is a hacker community classic. Today, [Zac Turner] shows us how this GPS drone can be autonomously controlled by a simple Arduino program or Python script.

What started as [Zac] sniffing some UDP packets quickly evolved into him decompiling the Android app to figure out what’s going on inside. He talks about how the launch command needs accurate GPS, how there’s several hidden features not used by the Android app, et cetera. And it’s not like it’s just another Linux SoC in there, either. No, there’s a proper Real-Time Operating System (RTOS) running, with a shell and a telnet interface. The list of small curiosities goes on.

After he finished reverse-engineering the protocol, he built some Python scripts, through which you can see the camera feed and control the drone remotely. He also went on to make an Arduino program that can do the latter using an Arduino Nano 33 IoT.