BayDesigns
Active member
What's the better choice? Pros and cons? Discrete surfaces can be mixed, but flaperons are lighter. Can someone point me in the right direction?
Flaperons vs Discrete Surfaces?
- Thread starter BayDesigns
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JasonK
Participation Award Recipient
The right direction is what ever works best for your use case.
The weight difference for discrete surfaces is going to be 1-2 extra servos over the flaperons (so if your really light, it might not work as well), however the surfaces are all smaller, so in some cases you might be able to use smaller sized servos, so that you don't end up adding much, if any weight.
The more distinct surfaces, the more control channels that are needed, so that is the other consideration.
Flight wise, I believe separate surfaces would be better as if you get close to a stall, your wing tips (ailerons) are not being used for the extra lift, which means they should be less close to a stall, meaning you would be less likely to end up dropping a wingtip if the wing stalls.
The weight difference for discrete surfaces is going to be 1-2 extra servos over the flaperons (so if your really light, it might not work as well), however the surfaces are all smaller, so in some cases you might be able to use smaller sized servos, so that you don't end up adding much, if any weight.
The more distinct surfaces, the more control channels that are needed, so that is the other consideration.
Flight wise, I believe separate surfaces would be better as if you get close to a stall, your wing tips (ailerons) are not being used for the extra lift, which means they should be less close to a stall, meaning you would be less likely to end up dropping a wingtip if the wing stalls.
quorneng
Master member
I agree with JasonK.
You have to remember that as the flying speed reduces the aileron function (whether separate or flaperons) become less effective. This requires ever greater surface movements to maintain control which, particularly with flaperons, greatly increases the chances of initiating a stall from the tip. At least with separate surfaces the flaps can be set to extreme lift angles with the ailerons undisturbed so the plane can go safely closer to the stalling point.
This is experimental STOL wing. Separate surface with extreme flap deflection.
Aileron authority at full flap requires big stick movements to keep the wing level.
A 40" wing it has a single 5g servo for each flap and a 3.7 g servo for each aileron.
It really depends on what you are trying to achieve. Flaperons are effective if you just want to increase the approach angle without a corresponding increase in speed but if you want to fly slowly then separate flap surfaces are better.
You have to remember that as the flying speed reduces the aileron function (whether separate or flaperons) become less effective. This requires ever greater surface movements to maintain control which, particularly with flaperons, greatly increases the chances of initiating a stall from the tip. At least with separate surfaces the flaps can be set to extreme lift angles with the ailerons undisturbed so the plane can go safely closer to the stalling point.
This is experimental STOL wing. Separate surface with extreme flap deflection.
Aileron authority at full flap requires big stick movements to keep the wing level.
A 40" wing it has a single 5g servo for each flap and a 3.7 g servo for each aileron.
It really depends on what you are trying to achieve. Flaperons are effective if you just want to increase the approach angle without a corresponding increase in speed but if you want to fly slowly then separate flap surfaces are better.
BayDesigns
Active member
Thanks! I’m definitely going to go with separate flaps for my next design. I really have to commit to building these, but I keep getting ideas! 🙄
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