Mountain Models Tantrum
55
situated, the landing gear will miraculously stay in place without glue or anything
else.
The good thing about using the 1/16" wire for the landing gear wire is that it's
lightweight. The bad thing about using this wire is that it can just barely hold
the airplane up when you use heavier batteries. With that being said, it's a
good idea to brace the gear by running some of the leftover pull-pull cable
across the gear about 2” up from the wheels.
Setting the Throws
You need to adjust your radio trim so that the elevator, rudder, and ailerons are all
level. The throws are all the same for the Tantrum, with the low rates being 30
°
and the
high rates being 45
°
. If you don't have an exponential- capable computer radio, 45
°
might be too much in which case you should limit the throws to 30
°
.
If your radio is capable of mixing, you may want to mix 50% flaps to elevator, so that
when the elevator goes up, the flaps go down. This will allow the Tantrum to perform
very tight loops.
Setting the Center of Gravity
The Center of Gravity (CG) will affect how the airplane recovers from a nose up or nose
down condition (pitch stability). With the CG too far forward, the plane will be quite
stable, but require a lot of up elevator to fly level. This will result in an increased low
end speed. On the other hand, too far back and the plane will be hard to control,
requiring constant input to keep the plane flying straight and level. For the Tantrum, the
CG should be 1/2" - 3/4" behind the rear of lower spar cap.
Flying
For your first flight, be patient and wait for a calm day. Choose a large field where you
have a smooth surface to use as a runway. Set the plane down, pointing away from you,
and if everything goes well, which of course it WILL, when you apply full power, your
plane will take off nicely after a slight rollout.
Bottom of the F2
bulkhead slot
Upside down view of the landing gear
