Dual Canard idea

[GeorgeC525]

I had this thought in my dreams, a dual canard system, I had some plane that looked like an F-22 in my dream but it had canards, the leading edge was slaved to the ailerons, the trailing edge was slaved to the elevators.

That sounds aerodynamically implausible though, so I thought how about having two sets of canards on the front of the plane, that work on a computer to give the plane stability/manouverability, where each canard set is slaved to a different flight control. I have no idea wheter this would improve aerodynamic effiecnty or make the plane really unstable, but here is a terrible drawing I done in MS paint to try and portray my idea

http://img84.imageshack.us/my.php?image=67060871eb6.jpg

[bevers01]

The short moment arm on the canards isn't going to give you radically better roll control, and will only drop your aero efficiency due to increased wetted area and induced drag from the low aspect surfaces. Making 2 canards is even worse, since now the aft one operates in the wash of the first, discouraging laminar flow and increasing drag. Plus, canards are mainly needed for deltas at high alpha due to elevator blanking, so they don't radically improve pitch control in normal flight for a conventional planform, either.

Long story short, don't do it for aero reasons. If you think it's cool, though, go for it. Aero efficiency doesn't stop flat plate foamies from being popular.

[GeorgeC525]

Yeah, I thought having them behind eachother would do something like that, disrupting the airflow.
An interesting idea would to be have a set on the rudder fins...

[Cory]

You mean like this:

[NX-687]

Having the canards oriented vertically might work
Giving a delta true yaw instead of the bank and nose down that they currently have from the dihedral of the swept wings

[JetPlaneFlyer]

Having the canards oriented vertically might work
Giving a delta true yaw instead of the bank and nose down that they currently have from the dihedral of the swept wings
If you put the canards vertically then they would not be canards, they would be 'fins'.. Albeit forward mounted ones. 'Vertical de-stabilizer' may be a more technically correct description..

I've seen forward mounted fins on some vintage freeflight flying wing designs, and on some vintage canards. I've never been able to figure out why they were used as any forward mounted fin will be directionally de-stabilising. If you wanted to reduce directional stability then IMHO making the conventional vertical stab smaller would be a better approach than adding a forward fin.

NX-687...What a forward vertical fin WONT do is remove the yaw/roll couple from a delta ;) If you want a model that will yaw without any roll couple build a straight wing model (i.e no sweep) with no dihedral and mid mounted wing/tail.... Any other layout is sure to have some form of yaw/roll couple.

[NX-687]

I will try a straight wing as you suggest

Also a question, seeing you guys are so good I thought I would hit you with this ---

Sloper Steve the guy that runs the slofly site has a fairly good hold on things that fly,, he was saying that on his flying wing delta types that he tried to angle the ailerons with the outboard part closer to the LE , quite a lot , something about curing adverse yaw
Is it worth putting a whole lot of angle on the aileron hinge line like that,,,, say 30 degrees or more

Thanks

Pardon me for hijacking the thread , will remember in future

[NX-687]

A flat LE works good , but makes a delta type plane look like a Pizza Box
Tip rockets work,,,,,,, flat wide ones, and and its going to be kind of fun experimenting with different shapes and lengths

[bbmaker]

i like your drawing- :)

[Texas Buzzard]

As I undersand this post you have the idea if a "delta" but also you want a canard in front near the nose. You want the canard slaved to elevator and the canard also slaved to the ailerons.

Dave Powers of RCSuperPowers ( a small design company located in California) has already sifted through all the radio problems for such a set up. If you go to <http://www.rcpowers.com/EuroFighter/EuroFighterAbout.htm> you will find not only a great video explaining how he did it, but there is a PDF plan for a foamy (6mm Depron) for sale at less than $8.00. He used to sell the kit for $29.00. I bought one last year.

When you pull "UP" elevator the movable surface of the canard goes down (lifting the nose. When to throw left aileron on the stick the canard does jut what the delta's surfaces (on the aft section) do. Left aileron on main surfaces and laso the canard give the same roll effect.

<http://www.rcpowers.com/EuroFighter/EuroFighterAbout.htm> go see.

*** Dave Powers has simlpified the electronics for slaving the canard servos to the main controls...that took him a lot of time to do that. It's worth seeing how he did it.