Sig Somethin Extra
 

I have heard a lot of people say that adding another inch to the rudder and adding a couter balance to the top will give a good performance boost to the extra. THe one thing I dont understand is the counter balance. What is it and what is its purpose. Thanks.

Sig Somethin Extra
 

It's the portion of the control surface which resides on the opposite side of the hinge. For example, a way to have a counter balance on the rudder is to make the add-on go up and over the top of the fin. When the main part of the rudder (behind the hinges) goes left, the counter-balance (ahead of the hinges) goes right. It eases the servo load by balancing out some of the force on the control surface.

Sig Somethin Extra
 

Ok, got it. Just for kicks, has anyone got a picture of this. Also, how much should I go over the fin and how many extra inches should I extend the rudder.

Sig Somethin Extra
 

I added an 1 1/2" all along the back of the rudder and an additional 1 1/2" at the top so it forms a counterbalance tab all the way to the leading edge of the vertical fin. The plane will now hover and fly unlimited knife edge with a Saito .72 and a 13 x 6 prop.

A counterbalanced surface serves two purposes; one to give aerodynamic 'help' to turning the surface, and perhaps more important is to help prevent destructive surface flutter by changing the critical flutter speed just like a mechanical counterbalance does.

While you're at it move the CG back a half inch or so behind the factory recomended point and the bird will still fly well, but help in hovering and 3D response. Some folks go even further aft with more flying skill.

quint :D

ARF
 

How would you do this with the ARF version ? Just by gluing a strip of balsa on the trailing edge and top shape it and then cover it ?

Sig Somethin Extra
 

Build a new rudder is the best and easiest option. the construction is quite straight forward and simple.

quint :D

Sig Somethin Extra
 

Here is a picture of my rudder counterbalance for your reference :

I just got some balsa and glued it to the top of my rudder and shaped the way I wanted it. I added about 2"

Sig Somethin Extra
 

I have one of those kits on the way as well. What, if any, mods should be done. You know like: "I wish I would have done that when I was building it." I have high expectations for this one, and want it to turn out best it I can make it.