Vertical stabilizer

[GDN]

I have a model 2

I have to apply a constant effort tu left rudder when i fly and it becomes hard during long flight.
I've heard that they increase the vertical stabilizer since Model 3 to have better yaw control.
I heard too that someone increase himself his one.
Is anybody have some measurement of the Model 3 and perhaps knows if it's better after increasing it.

Thanks.

[rwaltman]

You could ad a trim tab.

[Mnflyer]

Hi GDN, go to my photo album, I have pictures posted of my Model III that I increased the vertical fin area and add a small dorsal fin. These mods make a big difference in how the plane fly's. I added 2 inches to the leading edge of the vertical fin you can see it in the pictures.
http://www.teamkitfox.com/Forums/album.php?albumid=18
I also installed a trim tab but the additional of fin area is what really made the plane fly better the trim tab will reduce the needed pedal input.

[GDN]

I have one but no sufficient.

[Av8r3400]

Why not make it larger or increase its deflection?

[HighWing]

In readin this thread, it brings up a couple of observations and some related questions.

Observation: There is no thrust offset in any of the Kitfox engine mounts - at least Models I-IV. This means that with the 912, a bit of right rudder is common in cruise and with the counter rotating prop with the two cycle engines it usually requires a bit of left rudder. Like it or not, this is designed into the airplane. In most cases, a trim tab has reduced the work load or eliminated it as in my first Model IV.

Observation: The inprovemt in adverse yaw with the Model IV and later over the earlier models is attributable only partially to the larger rudder size. Much of the fix is in the flaperon mixer that gives proportional flaperon difflection in a bank. The draggy down flaperon movement is reduced about 50% relative to the less draggy up flaperon.

The questions are; how is a larger vertical stabilizer and rudder going to reduce the need for rudder difflection in cruise unless twist is added to the vertical stab? Is the inability to correct yaw with a trim tab common with this model and if not, is there something unique to this airframe that is causing the problem. is the ball centered in cruise? Flying one wing low will require rudder input to maintain heading. Which brings up wing rigging - will the wings remain level hands off with rudder input to maintain heading? If not, can the wings be adjusted with the lift strut rod ends. Can the engine mount be shimmed with washers, to add a bit of thrust offset?

I think before I would remake the vertical stab and rudder, I might try to see if there are other less invasive fixes. I just finished covering and painting my tail parts, and remaking the vertical stab and rudder will not be real easy and with the cost of materials, won't be particularly inexpensive.