The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1910-11-13

Bamboo or Cane Should Be
ChOsen-lmpOrtance of the
Curve and Double Motor.


aeroplane possible.
IL is only within the past few years
that we have guessed the secret of the
graceful flight of birds In the early
attempts to build flying machines, the
wings were made TO flap up and down.
The sad fate of Darius Green is case
in point; nor did the other imitators,
dating far back into ancient times, fare
any better When it was discovered,
however, that the birds might balance
themselves merely by bending the tips
of their wings, tho modern aeroplane
became possible.
A great MANY experiments have been
made to find whether the flat or the
curved wings give the better support,
and how sharply the curve should be
drawn. The wings of birds are curved
Slightly upward, and in the end, after
all the experiments, it has been found
that this curve is Just the right one.
All forms of aeroplanes will fly more
swiftly and steadily if the planes be
slightly bowed or flexed. After YOU
have built your aeroplane with flat
wings it will pay you to replace them
with flexed planes, and you will find
that your previous experience in build
ing models will make this construction
very simple.
Light Planes Best,
The lighter and more flexible mate
rials. such as bamboo or cane are best
for the curved planes After you have
decided upon the dimensions of the
wings, cut the pieces for the ends slight
'ly longer than the depth of your planes.
These pieces may then be bent by
steaming them over kettle of boiling
water and bendino TO the desired curve.
When dry they will hold their shape re
markably well Another plan is to
use a flexible strip and pull the ends
together by a strong thread or wire
until the wood is bowed to just the
right curve. A corset steel or whalebone
may readily be curved in the same way.
1t is common mistake to curve the
plane too sharply, when the resistance
offered to the air will be greater than
with the flat plane. In every case, the
end pieces of the planes and the inter
mediate stiffening ribs are bent with
the convex curve uppermost, so that
when the planes are covered with silk
or muslin, the whole plane will have the
convex side uppermost
a plane two or three feet In width
cannot be held in shape merely by cnrv-
ing the end. pieces, A series Of ribs
must be added at equal distances, each
having. of course, exactly the same up
ward curve. The ribs may be fastened
to the sides of the planes with small
brads or simply with glue or wire. The
covering should then be drawn tightly
over this frame and sewed or pasted
down. A very smooth covering may be
made of rice paper. Cut the sheets the
proper size and lay them for a few
minutes between moestened cloths. Now
stretch the paper carefully over the
frame and glue in position. When dry
the paper will contract and leave a
smooth, taut surface like the head of
q drum.
Curve Is Important.
Much depends upon the curve Of the
plane. A wing whose curve is not a
perfect arc of circle. but which is
Just back of the front edge
and 1attened at the rear, will be found
to offer the least resistance to the air. |
The best plan is to study the curves
of the large aeroplsnes and models and
initiate them. Different models require
planes. 1t is a problem which
each young aeronaut must work out for
himself.
The question of rudders or guiding
planes is very important. II is too
much to expect even Of the best model
that it will fly in an answering line.
Any simple vertical plane which may
be turned from side to side and held
in position will act as q rudder. There
is great difference of opinion as to guild. |
ing surfaces. 1t is argued by some
aviators that the rudder should be
placed above the plane, where the air
is undisturbed, while others believe that
the partial vacuum created above the
wings in flight makes this rudder inef-
feetive. Still others argue that rud |
der placed back of the planes affords |
a leverage, and is therefore more effec
tive. Try rudder IN each position. 1t |
is impossible to lay down law for all |
models
Twin Propellors Needed.
The larger models should be equipped |
With twin propellers, In building these |
the greatest care should be taken to |
have them exactly the same size, weight !
and pitch. Twin propellers should, as
q rule. be placed at the front of the
not push the planes. If by any accident |
the motor of one should fall, the sec
Ond propeller will continue to keep the
leroplane afloat and retard its fall on |
descending. With the propellers at the |
stern of the little airship, the failure
Of one would cause the plane to pitch |
downward, and the remaining propeller
would drive 1t down to possible disaster
In winding up the two motors care
should be taken to give both the same
number of turns. The aeroplane may
be launched by holding propeller in
either hand and releasing simutane-
ously. The double motor insures stead
Ter as well as longer flight Always
turn the propellers in opposite diree-
ions, In flying they must spin around
either toward each other or away from
each other IF they turn the same way
they will give the model torque which
no rudder could possibly overcome.
AS general rule. for plane three
Feet across make single propeller
fourteen inches in length. Should you
use two propellers with this machine,
make each twelve inches long.-Francis
Arnold Collins in St Nicholas
FRED GHARMAN AFTEP