trying2fly
Is there a plan for the use of Canards and Elevons working off the same servos?  Is so what plane would  incorporate  these ?   Is there in existence such a diagram or pictorial illustration that shows this?  Thanx to the forum !!!
Quote 1 0
F1wanabe
The only plane that did that was the rcpowers T50 but the problem is that the canard should move oppesite of the elevons and should never move up at the leading edge or else you will block the airflow over the wing and stall it! I call it the death dive where you go to pull up out of a dive and all control is lost as canards block all airflow over elevons and wing. It just drops. The best thing to do is use a separate servo or not activate them at all. I have an old thread on canards. They are meant to help route airflow over the wing at different angles of attack. They do not work as control surfaces for pitch. On the Eurofighter they are used to trim the plane while cruising. If you look up LEVCON (leading edge votex controllers ) and you can see how they work on T50's and SU's. They drop to increase airflow over a wing to create lift on the wing. So, that is why having them linked to the elevons would not work because at some point they would be moving upwards and blocking airflow. Hope this helps! 
https://www.rcpowers.com/post/to-canard-or-not-to-canard-that-is-the-question-10015709?pid=1307349635&highlight=canards
Quote 2 0
trying2fly
F1wanabe wrote:
The only plane that did that was the rcpowers T50 but the problem is that the canard should move oppesite of the elevons and should never move up at the leading edge or else you will block the airflow over the wing and stall it! I call it the death dive where you go to pull up out of a dive and all control is lost as canards block all airflow over elevons and wing. It just drops. The best thing to do is use a separate servo or not activate them at all. I have an old thread on canards. They are meant to help route airflow over the wing at different angles of attack. They do not work as control surfaces for pitch. On the Eurofighter they are used to trim the plane while cruising. If you look up LEVCON (leading edge votex controllers ) and you can see how they work on T50's and SU's. They drop to increase airflow over a wing to create lift on the wing. So, that is why having them linked to the elevons would not work because at some point they would be moving upwards and blocking airflow. Hope this helps! 
https://www.rcpowers.com/post/to-canard-or-not-to-canard-that-is-the-question-10015709?pid=1307349635&highlight=canards
      Thanx Greg.  I had another brainstorm I was about to try but now that I read your reply that makes perfect sense I shall give it up.  Thanx for saving me time, $$, and misery...lol!!chas     By the way that Canard link has spawned a whole host of ideas down here in the desert!!
Quote 0 0
quorneng
Pity to give up!
The blocking airflow over the wing issue does rather depend on the relative sizes of the canards to the rear wing and the planes general layout.
In say an XB70 the canards are relatively small and a long way ahead of the big delta but on mine they are pretty effective.
Newcmplt1.jpg
It was seriously lacking in elevator authority when first flown without them but the sheer distance between the elevons and canards does mean they have to have their own servos!           
Quote 5 0
F1wanabe
Yes, those canards would be more for trimming, I would think. The close coupled canards on the su or T50 or "closer coupled" canards like on the EF are what I'm referring to. Even smaller close couple canards and the LEVCON on the T50 has a dramatic effect on the airflow over the wing. 
Quote 2 0
trying2fly
quorneng wrote:
Pity to give up!
The blocking airflow over the wing issue does rather depend on the relative sizes of the canards to the rear wing and the planes general layout.
In say an XB70 the canards are relatively small and a long way ahead of the big delta but on mine they are pretty effective.     Wow you have changed my thinking again.  Now...I know what I want to do!!!  I will be using Canards but smaller and a longer fuse like yours!!!thanx!!!chas
Newcmplt1.jpg
It was seriously lacking in elevator authority when first flown without them but the sheer distance between the elevons and canards does mean they have to have their own servos!           
Quote 1 0
trying2fly
quorneng wrote:
Pity to give up!
The blocking airflow over the wing issue does rather depend on the relative sizes of the canards to the rear wing and the planes general layout.
In say an XB70 the canards are relatively small and a long way ahead of the big delta but on mine they are pretty effective.  Thank you very much!!
Newcmplt1.jpg
It was seriously lacking in elevator authority when first flown without them but the sheer distance between the elevons and canards does mean they have to have their own servos!           
Quote 0 0
trying2fly
quorneng wrote:
Pity to give up!
The blocking airflow over the wing issue does rather depend on the relative sizes of the canards to the rear wing and the planes general layout.
In say an XB70 the canards are relatively small and a long way ahead of the big delta but on mine they are pretty effective.

Please tell me how you made your round fuselage!!!chas
Newcmplt1.jpg
It was seriously lacking in elevator authority when first flown without them but the sheer distance between the elevons and canards does mean they have to have their own servos!           
Quote 0 0
quorneng
Most of my Depron planes fuselages are Depron planks over Depron formers.
For the XB70 the wing was built first and the rear part of the fuselage simply built on top of it.
CntrPlank1.jpg 
The nose section was separate and built as a 'half shell' over the plan with the other half of the formers added once it was lifted.
HalfPlank.jpg 
Does take a bit of patience but when complete the end result is extra ordinarily light and stiff.
Quote 1 0