hello all,
first, sorry about my bad english,

now back to the problem,
as i wrote in the topic, i have a tail wheel in my F3a model,
I need only a little angle for the Rudder for make the "knife edge",
but the problem is that i need a big angle for the tail wheel to turn back the model after the landing,


I dont have any d\r option for the rudder in my radio controller ( only with elevator and aileron).

so, what can i do .

Mongol,

You will need to drive your tail wheel via a small pushrod from your rudder instead of it being connected directly to your rudder. Your tail wheel would be free swiveling with a control horn and ball link. Then you would connect it to your rudder with another ball link. The increase in travel would come from the connection on the rudder would be at the far end of your rudder horn and the control horn (like a steerable nosegear horn) would be connected as close in as possible. This would give you a LOT of travel at your tailwheel with only a small amount of rudder movement. You would have to play with the distances to get exactly what you want, but this would work and is very simple. I've attached a drawing I made to illustrate this. If you have any questions, let me know.

Dan
Carolina Custom Aircraft

thank you very much, but i have only one more question, how can i connect the pushrod to the tail wheel ?

Mongol,

You will have a free swiveling tailwheel.... just like a steerable nosegear. You will put a control horn on the tailwheel wire and then put a ball link on the tailwheel control wire and a ball link on the rudder control horn. The attached diagram should show you how.. If you have any further questions let me know.


Dan Hines

Carolina Custom Aircraft

If you use the Sullivan tail wheel and mount it so that the tail wheel hinge point is behind the rudder hinge point, it will move more than the rudder. Since there is a limitd amout you can move it behind the rudder, I don't know if it will move enough for your purpose.

If you move the wheel pivot point way forward like on the P51 it will give you more steering with the same movement. It is also easer to install a retractable unit in the forward position.