New Quadcopter Speed World Record Set At Nearly 500 Km/h

May 13, 2024 by 20 Comments

Making a quadcopter go fast would seem to be quite simple: just strap on powerful motors, aim the quadcopter roughly at where you want it to go fast, and let ‘er rip. Because of aerodynamics and other pesky physical laws there are a few complications to this, of course, but this didn’t deter [Luke Bell] and his father [Mike Bell] from nailing the Guinness World Record for remote-controlled quadcopters on April 21, 2024. During the official run, a top speed of 480.23 km/h was recorded, making it considerably faster than the first version they made, which hit a measly 400 km/h.

For this second iteration of the ‘got to go fast’ quadcopter, the design was scaled up, with more powerful motors and associated electronics added. Naturally, when you’re pushing brushless motors and their ESCs to their limits, stuff can get a bit hot due to the immense currents flowing through the system. This resulted in a number of battery, wire and other fires. Fortunately, the worrying aspect of in-flight stability got addressed pretty well courtesy of a professional drone trainer, and ultimately the world record attempt went off without a hitch.

An endurance test was also attempted, which reached 7.5 km at 180 km/h, and with the clear canopy in from of the camera removed, visual performance was pretty stunning, while still easily reaching 400 km/h. This might make it the perfect high-speed chase camera system.

Thanks to [Craig] for the tip.

Continue reading “New Quadcopter Speed World Record Set At Nearly 500 Km/h” →

A Deep Dive Into Quadcopter Controls

January 1, 2024 by 3 Comments

In the old days, building a quadcopter or drone required a lot of hacking together of various components from the motors to the batteries and even the control software. Not so much anymore, with quadcopters of all sizes ready to go literally out-of-the-box. While this has resulted in a number of knock-on effects such as FAA regulations for drone pilots, it’s also let us disconnect a little bit from the more interesting control systems these unique aircraft have. A group at Cornell wanted to take a closer look into the control systems for drones and built this one-dimensional quadcopter to experiment with.

The drone is only capable of flying in one dimension to allow the project to more easily fit into the four-week schedule of the class, so it’s restricted to travel along a vertical rod (which also improves the safety of the lab).  The drone knows its current position using an on-board IMU and can be commanded to move to a different position, but it first has to calculate the movements it needs to make as well as making use of a PID control system to make its movements as smooth as possible. The movements are translated into commands to the individual propellers which get their power from a circuit designed from scratch for this build.

All of the components of the project were built specifically for this drone, including the drone platform itself which was 3D printed to hold the microcontroller, motors, and accommodate the rod that allows it to travel up and down. There were some challenges such as having to move the microcontroller off of the platform and boosting the current-handling capacity of the power supply to the motors. Controlling quadcopters, even in just one dimension, is a complex topic when building everything from the ground up, but this guide goes some more of the details of PID controllers and how they help quadcopters maintain their position.

Continue reading “A Deep Dive Into Quadcopter Controls” →

3D Printed Mini Drone Test Gimbal

October 9, 2023 by 4 Comments

Drones are a pain, especially mini ones. When you are designing, building (or even reviewing) them, they inevitably fly off in some random direction, inevitably towards your long-suffering dog, hit him in the butt and send him scuttling off in search of a quieter spot for a nap.

[Tristan Dijkstra] and [Suryansh Sharma] have a solution: a mini-drone test gimbal. The two are in the the Networked Systems group and the Biomorphic Intelligence Lab who use CrazyFlie drones in their work, which require regular calibration and testing. This excellent design allows the drone to rotate in three dimensions, while still remaining safely contained. That means I could test the flight characteristics of a drone without endangering my dogs important napping schedule.

Efforts involved attaching a light tether that restricts the drone until we know how the it flies, but what usually happens is that the tether gets trapped in a rotor, or the tether gets tight and the drone freaks out and crashes into the ground.

Using a gimbal is far more elegant, because it allows the drone to rotate freely in three dimensions, so the basic features of the drone can be established before you let it loose in the skies.

The gimbal was designed with the CrazyFlie in mind, but as there’s nothing more exotic holding the craft down than a zip tie, it should work with similarly sized quadcopters.

Continue reading “3D Printed Mini Drone Test Gimbal” →

Hefty 3D Printed Quadcopter Meets Nasty End

September 1, 2023 by 26 Comments

You can readily buy all kinds of quadcopters off the shelf these days, but sometimes it’s more fun to build your own. [Michael Rechtin] did just that, with a hefty design of his own creation.

The build is an exploration of all kinds of interesting techniques. The frame itself uses generative design techniques to reduce weight while maintaining strength, while the motors themselves make heavy use of 3D-printed components. The design is modular and much of it slots together, too, and it uses a homebrewed flight controller running dRehmflight. It draws 2.5 kW from its lithium polymer batteries and weighs over 5 kg.

The DIY ethos led to some hurdles, but taught [Michael] plenty along the way. Tuning the PID control loop posed some challenges, as did one of the hand-wound motors being 5% down on thrust.  Eventually, though, the quad flew well enough to crash into a rectangular gate, before hitting the ground. Any quad pilot will tell you that these things happen. Drilling into the quad with a battery still inside then led to a fire, which did plenty of further damage.

[Michael’s] quad doesn’t appear to be specifically optimized to any one task, and it’s easy to see many ways in which it could be lightened or otherwise upgraded. However, as a freeform engineering thinking exercise, it’s interesting to watch as he tackles various problems and iteratively improves the design. Video after the break.

Continue reading “Hefty 3D Printed Quadcopter Meets Nasty End” →

UAV Flight Controller Saves Weight

May 26, 2023 by 12 Comments

When building autonomous airborne vehicles like drones or UAVs, saving a little bit of weight goes a long way, literally. Every gram saved means less energy needed to keep the aircraft aloft and ultimately more time in the air, but unmanned vehicles often need to compromise some on weight in order to carry increased computing abilities. Thankfully this one carries a dizzying quantity of computer power for an absolute minimum of weight, and has some clever design considerations to improve its performance as well.

The advantage of this board compared to other similar offerings is that it is built to host a Raspberry Pi Compute Module 4, while the rest of the flight controllers are separated out onto a single circuit board. This means that the Pi is completely sandboxed from the flight control code, freeing up computing power on the Pi and allowing it to run a UAV-specific OS like OpenHD or RubyFPV. These have a number of valuable tools available for unmanned flight, such as setting up a long range telemetry and camera links. The system itself supports dual HD camera input as well as additional support for other USB devices, and also includes an electronic speed controller mezzanine which has support for quadcopters and fixed wing crafts.

Separating non-critical tasks like cameras and telemetry from the more important flight controls has a number of benefits as well, including improved reliability and simpler software and program design. And with a weight of only 30 grams, it won’t take too much cargo space on most UAVs. While the flight computer is fairly capable of controlling various autonomous aircraft, whether it’s a multi-rotor like a quadcopter or a fixed wing device, you might need a little more computing power if you want to build something more complicated.

Screenshot of the SDR software in action, with decoded data in a terminal, and a map that shows the location received from the decoded data

Loudmouth DJI Drones Tell Everyone Where You Are

March 26, 2023 by 43 Comments

Back when commercial quadcopters started appearing in the news on the regular, public safety was a talking point. How, for example, do we keep them away from airports? Well, large drone companies didn’t want the negative PR, so some voluntarily added geofencing and tracking mechanisms to their own drones.

When it comes to DJI, one such mechanism is DroneID: a beacon on the drone itself, sending out a trove of data, including its operator’s GPS location. DJI also, of course, sells the Aeroscope device that receives and decodes DroneID data, declared to be for government use. As it often is with privacy-compromising technology, turns out it’s been a bigger compromise than we expected.

Questions started popping up last year, as off-the-shelf quadcopters (including those made by DJI) started to play a part in the Russo-Ukrainian War. It didn’t take long for Ukrainian forces to notice that launching a DJI drone led to its operators being swiftly attacked, and intel was that Russia got some Aeroscopes from Syria. DJI’s response was that their products were not meant to be used this way, and shortly thereafter cut sales to both Russia and Ukraine.

But security researchers have recently discovered the situation was actually worse than we expected. Back in 2022, DJI claimed that the DroneID data was encrypted, but [Kevin Finisterre]’s research proved that to be a lie — with the company finally admitting to it after Verge pushed them on the question. It wouldn’t even be hard to implement a worse-than-nothing encryption that holds up mathematically. However, it seems, DroneID doesn’t even try: here’s a GitHub repository with a DroneID decoder you can use if you have an SDR dongle.

Sadly, the days of companies like DJI standing up against the anti-copter talking points seem to be over, Now they’re setting an example on how devices can subvert their owners’ privacy without reservation. Looks like it’s up to hackers on the frontlines to learn how to excise DroneID, just like we’ve done with the un-nuanced RF power limitations, or the DJI battery DRM, or transplanting firmware between hardware-identical DJI flight controller models.

Continue reading “Loudmouth DJI Drones Tell Everyone Where You Are” →

Turning A Pair Of Syringes Into A Tiny Water Pump

July 31, 2022 by 6 Comments

There is something inherently fascinating about tiny mechanical devices, especially when you’re used to seeing much larger versions. This is the case with [Penguin DIY]’s tiny centrifugal water pump built from 5 ml syringes.

The pump is powered by a small 8 mm diameter brushed DC motor, likely the same type that is used for small toy-grade quadcopters. The tiny impeller is a section of the syringe’s original plunger, with its cross-shaped body acting as the impeller blades. [Penguin DIY] first experimented with the original plunger seal to protect the motor from water, but it quickly melted from friction with the spinning shaft. Silicone sealant was used instead, and the motor shaft was covered with a layer of oil to prevent the sealant from sticking to it. Then the blob of sealant was flattened with a translucent plastic disc to allow clearance for the impeller.

A hole was drilled in the side of the syringe where the impeller sits, and a nozzle cut from the tip of another syringe was glued in place as the outlet. It’s notoriously difficult to get anything to stick to polypropylene syringes, but [Penguin DIY] says in the comments he was able to find an “organic superglue” that worked. With the motor and impeller inserted, the remaining space was also sealed with silicone.

This tiny pump packs a surprising amount of power, and was able to empty a 1.5 l bottle in about one minute with enough pressure to send the jet of water flying. There are still some issues that need to be addressed, though. With the motor completely sealed, it could burn itself quite quickly. A commenter also mentioned that it might suck water into the motor past the shaft after a hot run, as the air inside the motor cools and contracts. Even so, this little pump might be practical for applications that only require short runs, like watering potted plants. If you need more power you could always 3D print a larger pump.

Continue reading “Turning A Pair Of Syringes Into A Tiny Water Pump” →