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

beam.



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.