Canard

On Mon, 19 Feb 2007 16:27:02 GMT, Terence Lynock (MSW) wrote in :

Yes and no.

It obeys the same laws of aerodynamics.

The effects are different because of the different position. Considered only with the pressures on the moving surface, they are the same (pressure on top or pressure on the bottom).

If you rotate the canard (or its moving parts) against the relative wind in the same direction as "up elevator", the nose will be driven downward.

That rotation of the surface on the tail of the plane drives the tail downward and elevates the nose. But that's because the elevators are at the back of the plane, behind the CG, while the canard is at the front of the plane, ahead of the CG.

Moving the canard (or its moving parts) in the same direction as "down elevator" will lift the nose of the plane. When the elevator does that, it lifts the tail of the plane and depresses the nose.

Hope that helps.

Marty

Define "opposite".

When you move the elevator down, the canard goes up. When you move the elevator up, the canard goes down. This part is exactly the same as a horizontal stabilizer with an elevator. What the plane does is different.

Just hook up the radio, hold the plane at arms length in your left hand while moving the stick with your right. Move the plane the way it'll go in the air (making motor noises is optional). It should all be clear.

The message from "Martin X. Moleski, SJ" contains these words:

What I am thinking on is the servo would have to be linked up the opposite way round to a servo actuating a normal elevator on a tailplane?,

regards, Terry

On Mon, 19 Feb 2007 18:49:14 GMT, Terence Lynock (MSW) wrote in :

It depends on where you need to locate the servo to get the Center of Gravity (CG) right for the aiframe.

I prefer control horns under the movable surfaces--just for aesthetics.

Depending on the size of the aircraft, you might have the linkage inside the fuselage, out of sight, and could put the control horn above or below the hinge line as suited your taste.

Just hook it up the way you like. Then you can reverse the servo direction on the transmitter for that channel so that pulling the stick back causes the movement that would lift the nose (canard trailing edge goes down) or lower the nose (canard trailing edge goes up).

Marty