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Building Tips and technical articles. => Building techniques => Topic started by: Jim Pollock on February 02, 2009, 05:33:22 PM

Title: Tri Canard Linkage
Post by: Jim Pollock on February 02, 2009, 05:33:22 PM

Could someone, Dennis?

Please post a picture representing the correct flight surface linkages for a Tri-Canard aircraft??
I'm trying to figure out how to incorporate a forward canard surface on my project that only has it's
foam wing completed so far......

Thanks in advance,

Jim Pollock   ??? :o 8)

Title: Re: Tri Canard Linkage
Post by: Dennis Adamisin on February 02, 2009, 06:52:21 PM

Hi Jim

Basically you need a pushrod slaved off the flap rod - or even off the flap horn.  The horn on the canard must be over the top (same side as the flap horn) so the canard moves the same direction as the flaps.

As for ratio - your mileage may vary!  Recommend you have some way to adjust the throw.  I would suggest something like 3:2 (more canard than flap) for starters.

Title: Re: Tri Canard Linkage
Post by: Jim Pollock on February 02, 2009, 10:04:26 PM

Thanks Dennis,

That's about what I thought, but it never hurts to get another opinion.
Hmmm, what about the ration of canard to conventional surfaces?  Does 33-40 % sound O.K.?

Jim Pollock   ??? ??? ??? ???

Title: Re: Tri Canard Linkage
Post by: john e. holliday on February 03, 2009, 07:03:21 PM

What is a Tri-Canard?  I have flown and still fly the canard the Dick Sarpolous published years ago.  It has a forward stab/elevator in front of everything and flaps on trailing edge of wing.  The flaps on trailing edge of the wing have the movement cut down to where they barely move.  The elevator in front moves about 30 degrees up and down.  For up the elevator goes down and flap goes up and vice versa for down.  If you make them go the same direction you will not accomplish anything other than make the plane rise or descend.  I have witnesses that the Blue Goose will do a AMA pattern, not a 500 pointer but a recognizable pattern when engine is set right.  DOC Holliday

Title: Re: Tri Canard Linkage
Post by: Dennis Adamisin on February 03, 2009, 09:43:20 PM

Quote from: john e. holliday on February 03, 2009, 07:03:21 PM

What is a Tri-Canard? (snip)

One of these...

Title: Re: Tri Canard Linkage
Post by: john e. holliday on February 04, 2009, 11:45:55 AM

Thanks Dennis,  how did it fly?  I guess it wasn't worth the trouble of pursuing it.  Also is there plans for it?  DOC Holliday

Title: Re: Tri Canard Linkage
Post by: Dennis Adamisin on February 04, 2009, 04:29:20 PM

My brother modified one existing bird then build the yellow "Starship" shown in the pix.   I had drifted away from CLPA by then, but I got a chance to fly the yellow bird.  It had the darndest combination of rock soilid feel in level flight and hard corner.  It definitely deserves further review and refimnement.  As far as I know there is only one full scale Tri canard in production: the Piaggio P180 "Avanti".

Title: Re: Tri Canard Linkage
Post by: L0U CRANE on February 05, 2009, 07:22:46 PM

Denny,

I recall when Archie was having severe vision problems at a Nats. Very narrow 'tunnel vision'. If what he was looking at got outside the field of view, he had trouble recapturing it. One of the brothers was always ready to go help him if that happened. Was it you who bailed him out at a (?)Lake Charles(?) Nats? I was watching, partly because of the unusual layout, and partly because your (?)Eclipse(?) was one of the sharpest turning models I'd EVER seen.

More to the point, I recall being VERY impressed with the tri-surface model's turn ability...