As a South African, and despite it practically being our national sport, I’m not much one for patriotism or national pride. Yet, sometimes a fellow countryman does something so undeniably cool that I can’t help but feel a little undeserved secondhand smugness.
So it is with father and son team Mike and Luke Bell, who have (once again) designed and built the world’s fastest quadcopter drone. That might not sound impressive at first glance, but once you see how much engineering had to go into keeping the title of world’s fastest, I think you’ll be proud of them too.
How fast did they go? The drone hit 585 kilometers per hour, which is 363.502MPH!
The Mission: Speed Changes Everything
The drone in question is the Peregreen 3, which is their third record-breaking drone design. The dynamic duo put up records in 2023 and 2024, but that last record was toppled by a Swiss competitor known as Sammy.
In order to reclaim the title, they would have to go faster. However, as the various land, sea, and air speed records have shown over the years, progress slows to a crawl at the limits. You can’t just, for example, double your horsepower and get twice the speed. The harder you push, the more physics pushes back and having the last word in quadcopter speed wasn’t going to be quick or easy.
The eventually successful record-breaking attempt required Mike and Luke to go back to the drawing board, and the new design rested on three core pillars. First, a new fully 3D-printed structure to replace the previous carbon fiber frame. Second, a water cooling system to deal with the immense energy release required, and finally the pursuit of aerodynamic perfection to eke out every additional ounce of speed.
Drag, Shape and Passive Stability
At hundreds of miles per hour, air becomes a brick wall if you aren’t careful. In this case, the pursuit of speed revealed that the key to going faster was going to be about a better drag coefficient more than putting more wattage into the mix.
What I found interesting is how the team used a tool called AirShaper that allowed them to simulate airflow on their 3D models instead of using an expensive wind tunnel. This is the sort of software sim that companies paid millions for in the past, and it still amazes me that regular folks can now just access this power from a web browser.
Credit: Luke Maximo Bell via YouTube
Even so, no simulation is perfect, and they did do practical testing with smaller scale models in real wind. How? By mounting the scale model on a swivel and sticking it out the window of a moving car. If the model naturally stayed stable and pointed into the wind, they were on to something. This “passive stability” was what they were looking for, regardless of whether the shape that gave them that result looked strange or not.
Credit: Luke Maximo Bell via YouTube
To reduce drag even more, the team sealed up the canopy, giving the final model a smooth, closed top. Every opening was a source of turbulence, so even the electronics layout was dictated by airflow.
Power, Props and the Limits of Thrust
Credit: Luke Maximo Bell via YouTube
While power alone would not be enough, it’s a necessary ingredient here. We’re talking between 15 and 16 kilowatts of power at full throttle. This is why the top speed runs are brief. At full taps, the batteries would be empty in slightly over 20 seconds. According to the team, they have about 20% battery power left when the Peregreen 3 comes in for a landing after a run, which is not a fat safety margin by any measure.
That’s an almost absurd amount of energy for something that fits in a backpack. The drone’s RCN Power Supernova 3220 motors spin high-pitch APC 7×5-inch props, designed for thrust efficiency at high speed. Choosing the wrong propeller pitch can ruin performance; too steep, and the motors can’t spin fast enough; too shallow, and the drone runs out of “gearing” before terminal velocity.
The tips of those props can easily breach the speed of sound, which causes oscillation and instability. So getting the pitch wrong, or if the air density isn’t right at that moment, can lead to a fast unscheduled disassembly. That’s exactly what the Peregreen 3 team had to tune out through countless test flights.
Powering those motors required special batteries: Speedrun Drag Series V4 packs from SMC, designed for short, violent bursts of current. Each pack delivers enormous amperage for a few seconds before heat becomes an issue. Speaking of heat, oh boy…
Thermal Engineering: From Flaming ESCs to Water Cooling
Credit: Luke Maximo Bell via YouTube
With all that power onboard, and given how quickly and violently it has to be released to achieve these speeds, heat will always be an issue.
While there are various places heat can accumulate in a drone like this, for the Peregreen 3 the ESC (Electronic Speed Controllers) that convert the battery power into the energy pulses that turn the motors would literally catch fire.
To keep them alive, the team devised one of the wildest cooling systems ever put on a drone. They milled aluminum heat sinks, used thermal pads for direct contact, and then enclosed the ESCs in a resin-printed water chamber. This is one of the coolest solutions I’ve ever seen on a drone, and looks like it draws directly on PC water cooling designs.
Credit: Luke Maximo Bell via YouTube
Air ducts weren’t sufficient because it’s not possible to get the volume of air through the drone to cool it effectively. Also, adding vents makes the drag problem worse, so water cooling seems like the only solution that’s not self-defeating.
Materials, Manufacturing and Real-World Tradeoffs
Credit: Luke Maximo Bell via YouTube
That move to 3D printing had a long list of advantages. The structure was printed in a nylon-carbon composite, and using a printer meant exact control of both the internal and external structure.
They printed the main structure in Fibbron PA6 CF, a heat-resistant nylon with embedded carbon fibers, while structural inserts, gaskets, and cooling components came from resin and TPU prints. Even the aluminum heat sinks were CNC-milled in-house.
Credit: Luke Maximo Bell via YouTube
But there were tradeoffs. At 6lbs, the drone was heavier than ideal, and its flight endurance barely cracked two minutes under normal throttle. The 3D-printed body was tough but not indestructible, and each speed run risked a total loss if anything failed.
Credit: Luke Maximo Bell via YouTube
Still, the payoff was huge. After countless prototypes, crashes, and redesigns, the father-and-son team took Peregreen 3 to a test field and watched the telemetry climb: 570 km/h, then 585 km/h, making it (unofficially) the fastest quadcopter in the world.
Credit: DJI
9/10
Brand
DJI
Camera
1/1.3-inch CMOS, 48 MP
App
DJI Fly
Speed
16 m/s (S Mode)
The DJI Mini 4 Pro does just about everything you would want out of a drone in an incredibly compact, convenient, and highly functional package. The ease-of-use and image quality are best in class.
