The mixer tab on the Taranis made this prettty easy. Not sure how you would do it on other radios. Dont think i could have done it on my turnigy.
Each canard is done like the other control surface. Beveled, taped and hot glue reinforced. The version in the pic was the first version and more curvy. I straightened a lot of the lines to make hand cutting easier.
There is a way to fit variable foreplanes on the TT Based canard but it is a little involved.
Fit a 3.7Gram servo in the fuselage side under the foreplane in EACH side of the nose. Then you have 2 separate methods to follow.
1. Connect the right foreplane servo to the left elevon channel, (Y Harness), and fit foreplane servo so that the foreplane operates in the opposite direction to the left side elevon repeat the same connection for the left foreplane servo to the right side elevon. In this setup mode the maneuverability can be extreme, (especially in roll).
2. Modify the wing such than it has outboard ailerons and "Flaps". Connect the flaps to the foreplane elevator servos and plug them into the elevator port of the Rx. Mechanically ensure that the foreplane servos deflect the control surface in the opposite direction to that of the wing elevon/elevators. Fit the Aileron servos into the Aileron channel on the Rx (Optional - Mix flaps into the elevator channel). The Elevon mixing is NOT used! As usual rudder function is optional. The maneuverability is quite good especially in pitch/loops.
If using TX mixing for the elevons then splitting out the elevator will be impossible and so removing the Tx mix and mixing in a "V" tail mixer, (External), would be required.
You can set the wing to have ailerons only and the forward elevating canard but the distance between the canard and the wing would need to be far shorter than on the TT based version for elevator function to be very responsive.
The most important rule to remember CG may be KING but Expo RULES!
Whilst not strictly foam board although all the flying surfaces are very thin this has functioning canards set as elevators working in conjunction with the elevons at the back.
Originally it flew without any canards at all just as a plain delta but its pitch control effectiveness was rather limited despite the CofG set about as far back as possible and still remain flyable.
Even with the CofG moved forward (the weight of the canard is a long way ahead of the CofG!) the 'elevator' canards improved the pitch control to almost match that of roll so much so that it can perform a very non scale tight radius loop that a Eurofighter would be proud of!
On the full size the canards did not function as elevators. The whole canard was a 'fully flying' surface for trim and what looked like the elevator was only used as a 'flap' to hold the high angle of attack required for landing without having to use big rear elevator movement.