Building A PV Solar-Powered Quadcopter

November 1, 2025 by Maya Posch 65 Comments

The solar-powered quadcopter from below. (Credit: Luke Maximo Bell)

One of the most frustrating parts about flying a quadcopter is having to regularly swap battery packs, as this massively limits what you can do with said quadcopter, never mind its effective range. Obviously, having the sun power said quadcopter during a nice sunny day would be a much better experience, but how workable is this really? While airplanes have used solar power to stay aloft practically indefinitely, a quadcopter needs significantly more power, so is it even possible? Recently, [Luke Maximo Bell] set out to give it a whirl.

His quadcopter build uses a large but very lightweight carbon fiber frame, with large 18″ propellers. This provides the required space and lift for the solar panel array, which uses 27 razor-thin panels in a 9×3 grid configuration supported by a lightweight support frame.

Due to the lightweight construction, the resulting quadcopter actually managed to fly using just the direct power from the panels. It should be noted however that it is an exceedingly fragile design, to the point that [Luke]’s cat broke a panel in the array when walking over it while it was lying upside-down on a table.

After this proof of concept, [Luke] intends to add more panels, as well as a battery to provide some buffer and autonomous flying hardware, with the goal of challenging the world record for the longest flying drone. For the rest of us, this might make for a pretty cool idea for a LoRaWAN mesh node or similar, where altitude and endurance would make for a great combo.

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POV Globe Takes To The Skies

October 22, 2025 by Tyler August 12 Comments

LED billboards are cyberpunk-dystopian enough for most, but it can get worse. For example, this project by [Concept Crafted Creations] that takes the whole concept and takes it airborn (literally) in the form of a flying POV sphere called “Zippy”.

We love persistence-of-vision (POV) displays, and have featured plenty before, from the very complicated to the fairly simple. The idea is simple: take one or more rings of LEDs and spin them rapidly enough that the persistence-of-vision effect creates a solid image in your visual field. We covered the basics years back. “Zippy” has one ring of addressable LEDs that surrounds the thing that makes it unique: the quadcopter at its core. None of those other projects could fly, after all.

You might imagine a big, spinning ring is going to have a lot of torque to cancel out, and that is true — about 2.3 kgf — and it led to a lot of prototypes crashing early on. After trying to use flaps to direct the downwash of the quadcopter rotors to counter the spin, [Concept Crafted Creations] eventually added two extra props for yaw control, and that seemed to do the trick. We say “quadcopter” because that’s the configuration, but Zippy ended up heavy and needs eight lift motors to fly. PVC pipe and PLA aren’t the lightest build materials, after all. That’s ten props, total, plus another outrunner to spin the POV ring. All those motors, plus the current draw of the LEDs means the flight time might not impress — but Zippy sure does, at last as long as the batteries hold out.

There’s something eye-catching about POV displays, and seeing this one drifting upwards like Kang and Kodos decided to steal the Los Vegas Sphere is even more arresting. That made the crash at the end of the video sad to see, but [Concept Crafted Creations] hasn’t ruled out rebuilding it if his viewers show enough interest. So if you like what you see, head over to YouTube and leave an encouraging comment for him to try, try again. Continue reading “POV Globe Takes To The Skies” →

Making The Tiny Air65 Quadcopter Even Smaller

October 14, 2025 by Maya Posch 15 Comments

First person view (FPV) quadcopter drones have become increasingly more capable over the years, as well as much smaller. The popular 65 mm format, as measured from hub to hub, is often considered to be about the smallest you can make an FPV drone without making serious compromises. Which is exactly why [Hoarder Sam] decided to make a smaller version that can fit inside a Pringles can, based on the electronics used in the popular Air65 quadcopter from BetaFPV.

The 22 mm FPV drone with camera installed and looking all cute. (Credit: Hoarder Sam)

The basic concept for this design is actually based on an older compact FPV drone design called the ‘bone drone’, so called for having two overlapping propellers on each end of the frame, thus creating a bone-like shape. The total hub-to-hub size of the converted Air65 drone ends up at a cool 22 mm, merely requiring a lot of fiddly assembly before the first test flights can commence. Which raises the question of just how cursed this design is when you actually try to fly with it.

Obviously the standard BetaFPV firmware wasn’t going to fly, so the next step was to modify many parameters using the Betaflight Configurator software, which unsurprisingly took a few tries. After this, the fully loaded drone with camera and battery pack, coming in at a whopping 25 grams, turns out to actually be very capable. Surprisingly, it flies not unlike an Air65 and has a similar flight time, losing only about 30 seconds of the typical three minutes.

With propellers sticking out at the top and bottom – with no propeller guards – it’s obviously a bit of a pain to launch and land. But considering what the donor Air65 went through to get to this stage, it’s honestly quite impressive that this extreme modification mostly seems to have altered its dimensions.

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Improving Flying Drones By Mimicking Flying Squirrels

May 6, 2025 by Maya Posch 12 Comments

With the ability to independently adjust the thrust of each of their four motors, quadcopters are exceptionally agile compared to more traditional aircraft. But in an effort to create an even more maneuverable drone platform, a group of South Korean researchers have studied adding flying squirrel tech to quadcopters. Combined with machine learning, this is said to significantly increase the prototype’s agility in an obstacle course.

Flying squirrels (tribe Pteromyini)) have large skin flaps (patagium) between their wrists and ankles which they use to control their flight when they glide from tree to tree, along with their fluffy squirrel tail. With flights covering up to 90 meters, they also manage to use said tail and patagium to air brake, which prevents them from smacking with bone jarring velocities into a tree trunk.

By taking these principles and adding a similar mechanism to a quadcopter for extending a patagium-like membrane between its rotors, the researchers could develop a new controller (thrust-wing coordination control, TWCC), which manages the extending of the membranes in coordination with thrust from the brushless motors. Rather than relying on trial-and-error to develop the controller algorithms, the researchers trained a recurrent neural network (RNN) which was pre-trained prior to first flights using simulation data followed by supervised learning to refine the model.

During experiments with obstacle avoidance on a test-track, the RNN-based controller worked quite well compared to a regular quadcopter. A disadvantage is of course that the range of these flying squirrel drones is less due to the extra weight and drag, but if one were to make flying drones that will perch on surfaces between dizzying feats of agility in the air, this type of drone tech might just be the ticket.

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Why Not Build Your Quadcopter Around An Evaluation Board?

January 31, 2025 by Lewin Day 3 Comments

Quadcopters are flying machines. Traditionally, that would mean you’d optimize the design for lightweight and minimum drag, and you’d do everything in a neat and tidy fashion. The thing is, brushless motors and lithium batteries are so power-dense that you really needn’t try so hard. A great example of that is this barebones quadcopter build from [hebel23] all the way back in 2015.

The build is based around the STM32F4 Discovery Board, which [hebel23] scored as a giveaway at Electronica in Munich way back when. It’s plopped on top of a bit of prototyping board so it can be hooked up to the four controllers driving the motors at each corner. The frame of the quadcopter similarly uses cheap material, in the form of alloy profiles left over from an old screen door. Other equipment onboard includes a GY-273 electronic compass module, a MPU6050 3-axis gyroscope and accelerometer to keep the thing on the straight and level, and the Fly Sky R9B RC receiver for controlling the thing.

It might look crude, but it gets off the ground just fine. We’ve seen quadcopters using the STM32 in more recent years with more refined designs, but there’s something amusingly elegant about lacing one together with an evaluation board and some protoboard in the middle. If you’re working on your own flying projects, don’t hesitate to notify the tipsline!

Modular Multi-Rotor Flies Up To Two Hours

November 24, 2024 by Danie Conradie 27 Comments

Flight time remains the Achilles’ heel of electric multi-rotor drones, with even high-end commercial units struggling to stay airborne for an hour. Enter Modovolo, a startup that’s shattered this limitation with their modular drone system achieving flights exceeding two hours.

The secret? Lightweight modular “lift pods” inspired by bicycle wheels using tensioned lines similar to spokes. The lines suspend the hub and rotor within a duct. It’s all much lighter than of traditional rigid framing. The pods can be configured into quad-, hex-, or octocopter arrangements, featuring large 671 mm propellers. Despite their size, the quad configuration weighs a mere 3.5 kg with batteries installed. From the demo-day video, it appears the frame, hub, and propeller are all FDM 3D printed. The internal structure of the propeller looks very similar to other 3D-printed RC aircraft.

The propulsion system operates at just 1000 RPM – far slower than conventional drones. The custom propellers feature internal ring gears driven by small brushless motors through a ~20:1 reduction. This design allows each motor to hover at a mere 60 W, enabling the use of high-density lithium-ion cells typically unsuitable for drone applications. The rest of the electronics are off-the-shelf, with the flight controller running ArduPilot. Due to the unconventional powertrain and large size, the PID tuning was very challenging.

We like the fact this drone doesn’t require fancy materials or electronics, it just uses existing tech creatively. The combination of extended flight times, rapid charging, and modular construction opens new possibilities for applications like surveying, delivery, and emergency response where endurance is critical.

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Transforming Drone Drives And Flies

November 22, 2024 by Danie Conradie 8 Comments

Vehicles that change their shape and form to adapt to their operating environment have long captured the imagination of tech enthusiasts, and building one remains a perennial project dream for many makers. Now, [Michael Rechtin] has made the dream a bit more accessible with a 3D printed quadcopter that seamlessly transforms into a tracked ground vehicle.

The design tackles a critical engineering challenge: most multi-mode vehicles struggle with the vastly different rotational speeds required for flying and driving. [Michael]’s solution involves using printed prop guards as wheels, paired with lightweight tracks. An extra pair of low-speed brushless motors are mounted between each wheel pair, driving the system via sprockets that engage directly with the same teeth that drive the tracks.

The transition magic happens through a four-bar linkage mounted in a parallelogram configuration, with a linear actuator serving as the bottom bar. To change from flying to driving configuration the linear actuator retracts, rotating the wheels/prop guards to a vertical position. A servo then rotates the top bar, lifting the body off the ground. While this approach adds some weight — an inevitable compromise in multi-purpose machines — it makes for a practical solution.

Powering this transformer is a Teensy 4.0 flight controller running dRehmFlight, a hackable flight stabilization package we’ve seen successfully adapted for everything from VTOLs to actively stabilized hydrofoils. Continue reading “Transforming Drone Drives And Flies” →