PUTTING ON THE RUDDER.
Gliders as a rule have only one rudder, and this is in
the rear. It tends to keep the apparatus with its head to
the wind. Unlike the rudder on a boat it is fixed and
immovable. The real motor-propelled flying machine,
generally has both front and rear rudders manipulated
by wire cables at the will of the operator.
Allowing that the amateur has become reasonably expert
in the manipulation of
he glider he should, before
constructing an actual flying machine, equip his glider
with a rudder.
Cross Pieces for Rudder Beam.
To do this he should begin by putting in a cross piece,
2 feet long by 1/4x3/4 inches between the center struts,
in the lower plane. This may be fastened to the struts
with bolts or braces. The former method is preferable.
On this cross piece, and on the rear frame of the plane
itself, the rudder beam is clamped and bolted. This
rudder beam is 8 feet 11 inches long. Having put these
in place duplicate them in exactly the same manner and
dimensions from the upper frame The cross pieces on
which the ends of the rudder beams are clamped should
be placed about one foot in advance of the rear frame
The Rudder Itself.
The next step is to construct the rudder itself. This
consists of two sections, one horizontal, the other vertical.
The latter keeps the aeroplane headed into the wind,
while the former keeps it steady--preserves the equilibrium.
The rudder beams form the top and bottom frames of
the vertical rudder. To these are bolted and clamped
two upright pieces, 3 feet, 10 inches in length, and 3/4
inch in cross section. These latter pieces are placed about
two feet apart. This completes the framework of the
vertical rudder. See next page (59).
For the horizontal rudder you will require two strips
6 feet long, and four 2 feet long. Find the exact center
of the upright pieces on the vertical rudder, and at this
spot fasten with bolts the long pieces of the horizontal,
placing them on the outside of the vertical strips. Next
join the ends of the horizontal strips with the 2-foot
pieces, using small screws and corner braces. This done
you will have two of the 2-foot pieces left. These go in
the center of the horizontal frame, "straddling" the
vertical strips, as shown in the illustration.
The framework is to be covered with cloth in the
same manner as the planes. For this about ten yards
will be needed.
Strengthening the Rudder.
To ensure rigidity the rudder must be stayed with
guy wires. For this purpose the No. 12 piano wire is
the best. Begin by running two of these wires from the
top eye-bolts of stanchions 3 and 4, page 37, to rudder
beam where it joins the rudder planes, fastening them
at the bottom. Then run two wires from the top of the
rudder beam at the same point, to the bottom eye-bolts
of the same stanchions. This will give you four diagonal
wires reaching from the rudder beam to the top
and bottom planes of the glider. Now, from the outer
ends of the rudder frame run four similar diagonal wires
to the end of the rudder beam where it rests on the
cross piece. You will then have eight truss wires
strengthening the connection of the rudder to the main
body of the glider.
The framework of the rudder planes is then to be
braced in the same way, which will take eight more
wires, four for each rudder plane. All the wires are
to be connected at one end with turn-buckles so the
tension may be regulated as desired.
In forming the rudder frame it will be well to mortise
the corners, tack them together with small nails, and
then put in a corner brace in the inside of each joint.
In doing this bear in mind that the material to be thus
fastened is light, and consequently the lightest of nails,
screws, bolts and corner pieces, etc., is necessary.