A collar is fixed on to the tube by a 6-mm. bolt. It will prevent the
tube from sliding in the rubber shook absorber, in the same way that the block holds the
latter under the skid of the body. Do not drill any hole in the axle at this spot. A piece of 8-mm. rod goes through the axle at its middle point, and a tube made out of sheet metal of 1 mm. is rolled round. The rubber washers are then inserted between the two metal washers and the whole is held in place by a nut. This prevents the axle from turning, by supporting it on the front planking through the hole.
The axle bears down on the pad of rubber of a thickness of 12 mm. cut from
the tread of an old motor-car tyre (Fig. 19). This pad is fixed on the .6-mm. aluminium washer and held by two screws and a plate.
Elastic Suspension
The rubber shock absorber of 12 mm. diameter, which commences to stretch under a pull of 40 lbs., and which has a length of 1 metre 90 mm., is fixed at each end into a metal fastening in metal of 1 mm. with a bolt of 4 mm. One end of the shook absorber is fixed under the axle by a screw in 4 mm. x 20 mm. The shock absorber passes behind the stop, and afterwards six times round the axle, and under the skid, an shown in the drawing. One pulls on it until it is just slightly stretched.
The other end receives a wire 2 mm. diameter, which will he securely attached to a screw placed conveniently under the seat planking. The screw prevents the last turn slipping.
Before cutting the shock absorber, bind it with rubber tape (two turns), and cut in the middle of the binding with a knife.
In its longitudinal view the suspension appears as shown in Fig. 19, which shows the axle, its collar, its pad of rubber, the strip of aluminium, the longeron of the fuselage, the skid which reinforces it, and the lower stop with the three turns of the shock absorber on eitherside; which make altogether, on each side of the body, twelve turns of shock absorber. The machine could roll on one wheel without stretching the shock absorber, except over bumps.
The wheels are fixed on the ends o f the axle by washers and collars (using a 5 mm bolt horizontally) cut out in metal of 2 mm. thickness. Pieces of tube 40 mm. x 44 mm diameter, of a length of 15 mm., will also be quite suitable. Interpose a washer between the wheel and the sleeve.
The Wheels
The dimensions of the tyres should be 450 mm. x 100 mm., which, when lightly inflated, absorb most of the roughnesses of the ground. Only the bigger shocks will have to be taken by the shock absorber.
One blows up these pneumatic tyres so that they hardly preserve their roundness. Frequently grease the axle.
The body of the fuselage is 35 in. from the ground. It may seem rather small, but it is quite sufficient. However, make a careful inspection of the ground from which you are taking off, and flatten with blows from a spade any bumps which seem a bit too high.
The Control Stick
A tube traverses the fuselage from side underneath the rectangular hole.The centre of the tube is held between two blocks and two cheek pieces by four bolts 5 mm. diameter. Between these strips, and the 6 mm. bolt and the washers of 1 mm., the control stick pivots. On the top of this stick is riveted a steel hook of 2 mm., which will prevent your hand from slipping of, and also will enable you to join the stick to the dashboard bv rubber strips cut from an old pneumatic tyre. These strips will relieve the pilot of the continuous pull of the stick in a forward direction.