3 ms·

How does this perform cross wind compared to a traditional micro quad? That main rotor will act like an umbrella does in a gust of wind. The micro quads don't

How does this perform cross wind compared to a traditional micro quad? That main rotor will act like an umbrella does in a gust of wind. The micro quads don't suffer the same problem. I'm not sure of the physics involved (and if anyone knows i'd love to learn more!) but just from hands-on piloting both micro quads and larger helis, the micro quads are some of the least susceptible to cross winds i've ever flown.

loup-vaillant 13y ago
Accelerometers are bound to detect such adverse effects. Correcting roll and pitch automatically shouldn't be hard. Also, I would guess that the higher the main rotor (compared to the centre of mass), the more susceptible the device. So, if you build the main rotor as close to possible as the centre of mass, you should have a more neutral design. While we're at it, I've flown a little toy with two main rotors, rotating in opposite directions, controlling power and yaw, while the tail rotor controlled pitch (the whole thing was auto-stable, so there was no need for roll control). It worked like a charm. So, if we're willing to suffer the complexity of an actual swashplate[1], we could try a design with 2 main rotors, one above, and one below, hereby getting a neutral, manoeuvrable, and (hopefully) efficient design. [1]: https://en.wikipedia.org/wiki/Swashplate_%28helicopter%29 https://en.wikipedia.org/wiki/Swashplate_%28helicopter%29
- CraigJPerry 13y ago
  AIUI there's all sorts of considerations & trade-offs. E.g. the motors have a limit to how quickly they can change output (up to around 400Hz today). Because there's no swashplate on the upper rotor of those wee co-axial rotor designs, they're really ineffective in cross wind. You can't apply the required corrective input when the top rotor gets blown off axis.
  - loup-vaillant 13y ago
    The design I was thinking about puts the lowest rotor below the gravity centre. First, it would lower the highest rotor, and second, crosswind would have the opposite effect on the low rotor. I really expect such a design to be neutral.
Dave_Rosenthal 13y ago
The conventional wisdom is that rc quads are _more_ susceptible to winds than rc acrobatic helicopters (and have lower max speeds) largely because they usually have a "cupped" shape to their props (to maximize efficient static thrust) which can catch catch a cross wind. In contrast an acrobatic rc heli has perfectly straight/flat blades that change pitch to create lift and are quite "invisible" from the side. That said, in this design, having two different types of rotors mounted non-symmetrically seems bound to induce some yaw from winds.

loup-vaillant 13y ago

Accelerometers are bound to detect such adverse effects. Correcting roll and pitch automatically shouldn't be hard. Also, I would guess that the higher the main rotor (compared to the centre of mass), the more susceptible the device. So, if you build the main rotor as close to possible as the centre of mass, you should have a more neutral design. While we're at it, I've flown a little toy with two main rotors, rotating in opposite directions, controlling power and yaw, while the tail rotor controlled pitch (the whole thing was auto-stable, so there was no need for roll control). It worked like a charm. So, if we're willing to suffer the complexity of an actual swashplate[1], we could try a design with 2 main rotors, one above, and one below, hereby getting a neutral, manoeuvrable, and (hopefully) efficient design. [1]: https://en.wikipedia.org/wiki/Swashplate_%28helicopter%29 https://en.wikipedia.org/wiki/Swashplate_%28helicopter%29

CraigJPerry 13y ago
AIUI there's all sorts of considerations & trade-offs. E.g. the motors have a limit to how quickly they can change output (up to around 400Hz today). Because there's no swashplate on the upper rotor of those wee co-axial rotor designs, they're really ineffective in cross wind. You can't apply the required corrective input when the top rotor gets blown off axis.
- loup-vaillant 13y ago
  The design I was thinking about puts the lowest rotor below the gravity centre. First, it would lower the highest rotor, and second, crosswind would have the opposite effect on the low rotor. I really expect such a design to be neutral.

Dave_Rosenthal 13y ago

The conventional wisdom is that rc quads are _more_ susceptible to winds than rc acrobatic helicopters (and have lower max speeds) largely because they usually have a "cupped" shape to their props (to maximize efficient static thrust) which can catch catch a cross wind. In contrast an acrobatic rc heli has perfectly straight/flat blades that change pitch to create lift and are quite "invisible" from the side. That said, in this design, having two different types of rotors mounted non-symmetrically seems bound to induce some yaw from winds.