Canard angle? sky hunter

[bobogofast]

Have a sky hunter kit laying around really love canard designs so was thinking about putting a canard on the front of the fuse and shorten the rear tail section. My hope is that by adding the canard at the front will help stabilize the plane and counter the shortened length of the tail? As for the canard was wondering if i should just put it in level to the wing or put it with a 2-3 degree of up incidence so that it would stall before the main wing or would this just cause it to pitch up?

 

[earthsciteach]

The canard is a full airfoil generating lift as opposed to the tail of an aircraft that actually generates downforce to counter the tendency of the nose to pitch down. If you are using a flat surface you absolutely must have some up angle for it to be effective.

One of the benefits of a canard aircraft is that the canard is usually designed to stall before the main wing. This prevents a main wing stall as the nose will drop prior to that happening. So, even if you have a full airfoil on the canard you might want to use a couple of degrees of incidence.

Be prepared for the cg location to shift dramatically! You will likely end up moving components forward.

 

[bobogofast]

It will be just a flat piece. Is there an ideal angle or an idea of how many degrees up it should be? hoping to get the cg forward as the plane is very tail heavy and made to carry a lot of weight up front. i am wanting to run the plane very light though so hopefully this will work to my advantage

 

[earthsciteach]

That's a tough one. I would say that it should be at least 2 degrees greater than the angle of incidence of the wing. But, that all depends on the area of the canard and the airspeed.

If the plane is naturally tail heavy, you may be compounding the issue by using a canard. The canard will cause an even greater pitch up unless there is enough weight up front to correct it.

 

[ProfessorFate]

When RC Homebuilts made something like the Long EZ they said the incidence of the canard was 3 degrees and that canards as small as 4" in chord length did not work

I think what may work better for control, is if the canards are like a NACA 9 or 10 at least, that's just a symetrical foil 9 or 10% thick

Have you ever noticed thin wings stall quicker than those with thin foils or flat, you take some kind of stunt/funfly with a fat airfoil like 16%, it would probably be hard to see a hi speed stall, if it's a canard I would want it to have a foil, thinking about, well how does it work with the FT Mustang or Storch, the same stab is flat and works good, I guess because it is pulled from behind instead of a canard

Anyway I have always liked to play with custom funfly planes in RealFlight 3.0 and the wings with fat symmetrical foils handle stalls the best, with a NACA 16 you never see a hi speed stall, course you can sure slow down and hit the limit and force a stall but it comes down real nice and easy

Even tho that's just a sim, with regards to this aspect of wing stall, it's probably close or right on.

You might be sure your canards have at least 5 or 6" of chord to be effective

good luck with that, I like special projects and pushers, seen the long ez, dh2, fe2, bd5 from the bond film?

Leonard

 

[Spastickitten]

just as an experiment, make one with servos moving the canard, adjust it until it flies the way you want it to.

 

[bobogofast]

Wasn't going to be using the canard for control but that is an interesting idea putting it on a servo so can be adjusted. The main reason for adding it was because i wanted to shorten the tail length of the plane and was hoping that would help the plane be more stable in regards to pitch?

 

[saiga556]

Wasn't going to be using the canard for control but that is an interesting idea putting it on a servo so can be adjusted. The main reason for adding it was because i wanted to shorten the tail length of the plane and was hoping that would help the plane be more stable in regards to pitch?

I for one think it would be a waste to not use the canard for pitch control. You may find some interesting effects could be produced by coupling the canard and elevons for pitch.