This is the worlds largest RC magnus-effect aircraft.
A huge project that’s taken months of work just to see if we can actually get it to fly using these strange spinning rotors to create lift.
The Magnus Effect, in case you didn’t know, is where a spinning object redirects the oncoming air.
As the spinning object moves through the air, it drags air around and redirects it, creating a pushing force.
A while ago I had a go at building a plane that used this principle to fly, but it didn’t work too well! Check out that project below.
So, our challenge? To successfully build the world’s largest RC giant Magnus effect plane to get it to fly and land safely.
Step 1. Initial Experiments
I thought the best approach would be to modify a micro RC plane through replacing its wing with a magnus effect rotor, to learn exactly how to make the most effective magnus effect wing.
We got our mini cub from our friends at The Vintage Model Company.
Planes stay in the air by balancing four important forces: lift, weight, thrust, and drag.
To get our small RC plane flying with the magnus effect, the magnus effect wing needed to create enough lift to overcome the plane’s weight.
So, with a bit of balsa wood I put together some basic magnus effect wings.
For the spinning part, I used a strong but light carbon rod as the axle.
It was then time to put the wing onto an RC plane and take it outside for a test flight.
Unfortunately, enough lift wasn't being generated by out rotating wing and our plane immediately crashed into the dry stone wall below.
After some iterations, I came up with a much better spinning rotor with multiple sections to better balance the wing as it span and more importantly, I made the spinning part much smoother, so it could rotate more freely.
After another test, we saw our wing was working, but it still had a lot of problems we would need to fix.
Step 2. Building a more optimised aircraft
After learning so much from the first tests, we designed a brand-new plane from scratch.
I started with the fuselage, keeping it lightweight but strong and followed similar principles for the tail
I used foam sheets to construct it, keeping the design simple but functional.
Next was the rotary wing. It would be around three times larger than the tiny balsa-wing prototype, meaning it had to handle much greater forces.
It needed to be perfectly straight, incredibly strong, and able to rotate as smoothly as possible.
To achieve this, I went with another carbon tube from Easy Composites and mounted it on precision bearings to keep friction to a minimum.
I had some concerns about how accurately everything was built, but at the end of the day, this was still just a prototype we would use for research and development.
At the first sign of half-decent February weather, we headed to the field for the plane’s first flight which proved that the aircraft was, at the very least, stable.
At full throttle, the plane climbed steadily, gaining enough altitude but it quickly became clear that the plane was severely underpowered.
The spinning rotors created a huge amount of drag, and the motors just weren’t strong enough to fully overcome it.
It just about stayed in the air, but only just.
Step 3. Attempting to increase power
The next step was to upgrade the plane with a much more powerful electronics system.
This involved swapping out the small drone motors for two twin electric ducted fans— which were far more powerful providing much more thrust, but this also meant the new power system was heavier.
Although the plane now had more thrust—it effectively had less lift to keep it in the air.
Another test flight was needed to give us much needed answers and although we had clear skies, the wind was picking up.
The plane had far more thrust than before and could climb more aggressively but it wasn't coping with the wind well.
The added weight meant that stalls were much sharper and more aggressive.
On one particularly wild flight, the plane climbed beautifully into the wind—only to suddenly stall at the top and nose-dive straight down.
For a brief moment, it was heading directly for a drystone wall at full speed.
At this point, we’d learned something important: we had officially reached the weight limit of this aircraft.
Step 4. Attempting to increase lift
We had a big problem with this plane and that was the four forces of flight were out of balance.
What we needed to do was to increase the plane’s lift so our next idea was to power the spindles directly with a motor.
Instead of relying on the airflow to spin it passively, we could force it to rotate using a motor.
If this worked, it could massively increase lift and help counteract the extra weight.
This meant designing and assembling a system with a powerful brushless motor, a belt drive, and a set of 3D-printed pulleys to transfer power to the carbon axle.
It did seem to spin well, and at this stage, things were looking positive but a lot of weight had been added to the system and to make matters worse, we noticed some nasty vibrations.
There was only one way to find out whether these would impact the functionality, and that was through another sketchy test flight.
During the test flight we were definitely generating more lift, but it still wasn’t quite enough to offset the mass of the new powered rotor system so, it had to go.
Step 5. Scaling it up
The main problem with our plane was that it didn’t have enough lift to stay in the air, especially with the relatively heavy electronics we had fitted.
The plan had always been to scale up the design, but what I didn’t realise at the time was that scaling up was exactly what we needed to do to get more lift.
For anyone who’s not an aerospace engineer, when you double the wing area, the lift doesn’t just double—it actually quadruples.
So, if we scaled the plane up to twice its current size, we would theoretically get four times the lift.
After a couple of weeks of hard work, the new aircraft was ready for its first test flight!
After a few runs up and down the car park, I was starting to get a good feel for how the larger plane handled.
The world’s largest RC Magnus effect aircraft could just about take off and fly, and we were nearly ready for the final test flight in the field!
At this point, I felt it could really use a bit more power to be on the safe side, so I swapped the ducted fans for propellers.
They should give us much more thrust at lower speeds, which was exactly what we needed.
Starting small, we have overcome each challenge one by one, proving that these unusual spinning wings can actually lift a conventional aircraft and I finally think we have all four forces of flight balanced, but obviously anything can happen on a test flight and success isn’t guaranteed.
Thank you for reading and keep an eye out on the channel for updates on this experimental aircraft!