| First let's understand
the difference between a hunt and a wag. It's important to know which
symptom you have because the cause is entirely different. |
|
| Hunting is a
fast violent change of direction at least 5 times per second. The fix
for this is simply reducing the gain or controlling your headspeed.
Other possible fixes are shortening the tail rotor servo arm or using
shorter tail blades.
|
Hunting can
damage your model! If you let the t/r hunt, it's just a matter of time
before you strip gears or take teeth off your belt. FIX IT. |
| Here are the
things to check when you have a wag. Any or all of them can create
the
problem. |
A wag is a much slower
change in direction. I sometimes refer to a wag as "Looking around".
|
|
|
Do whatever it takes to make your t/r
control rod as smooth as silk. Spare no effort because this is the key
to a good tail. |
|
|
When this is the case, the tail seems very sensitive and moves with the
slightest change in rudder or pitch. It overshoots when you let go of
the rudder stick. Try raising the gain a few points. |
- Improper installation of thrust
bearings is one of the most common causes of wagging. The
illustration shows the proper assembly.
|
You should check this, even if your model
was an ARF. Thrust bearings have three parts. An inner race, a ball cage
and an outer race. The inside diameter of the outer race is smaller than
the inside race. The race that goes on the shaft first has to be a loose
fit. If it is tight, the t/r grip can't rotate freely and you will get a
wag. |
- Lack of oil on the t/r output
shaft
|
Electric and gas models are especially prone to this problem. A single
drop of Tri-Flow on the tail rotor output shaft could make the
difference. |
|
|
Depending on what type of flying you do, you might be able to get away
with a slower servo here. However, it is generally best to use a servo
designed for the tail rotor. Even some of these aren't as good as
others. You definitely get what you pay for |