Details

The AOS 3.5" was born from an analysis of quadcopter weight against prop size. The result was the identification of disc loading as a key parameter that could be compared between quads of different sizes and was a strong predictor of flight performance for freestyle flying.

By looking at the flight performance of a large number of quads it was possible to identify the ideal disc loading for a freestyle drone and thereby calculate the ideal prop size for an FPV freestyle drone of a given weight.
When that analysis is performed for 250g the ideal prop size turns out to be very close to 3.5" and several good 3.5" props are available.

AOS used Blackbox logging and harmonic analysis to visualize the vibrations of the AOS 3.5 V2 during the design process. For the V2, theys combined this with topology optimisation to tune the geometry of each part of the frame, moving the frame resonances up and away from the motor frequencies and separating them as far as possible. This avoids, as far as possible, the situation where the motor frequencies match a frame resonant frequency and so amplification is minimized.

As a result, you can run less filtering. Every layer of filtering adds delay that’s mathematically related to how effectively it removes vibrations. This delay prevents the flight controller from responding rapidly enough to propwash leading to poor propwash handling. Reducing the amount of filtering is the best way to improve propwash handling. With the AOS 3.5 V2 you’ll be in the best possible position to reduce your filtering to an absolute minimum.​

Another advantage of lower noise is the ability to run higher PID gains. Higher PID gains allow the quad to track your stick movements with less delay and more precision. The result is greater confidence, particularly when flying tight lines where fast reactions are vital.