From the lower ends of these struts CC, Fig. 27, diagonal struts DD run back to the fuselage. These are of ash, 1 3/16 by 2 1/2 inches and 2 feet inches long. The rear ends of the struts DD are fastened to the fuselage beams by the projecting ends of the U-bolts of the horizontal fuselage struts, and also by angle plates of sheet steel. At the lower front ends the struts DD are fastened to the struts CC and the beam E by steel angle plates, and the beam is reinforced by other plates on its under side.
Trussing. In the genuine Bleriot, the framework is trussed by a single length of steel tape, 1 1/8 by 1/16 inch and about 11 feet long, fastened to U-bolts in the beam A, Fig. 27. This tape runs down one side, under the beam E, and up the other side, passing through the beam in two places, where suitable slots must be cut. The tape is not made in this country, but must be imported at considerable expense. Ordinary sheet steel will not do. If the tape can not be obtained, a good substitute is 1/8-inch cable, which then would be made in two pieces and fastened to eye bolts at each end.
Fig. 27. Details of Bleriot Running Gear
Fig. 28. Details of Various Fittings for Bleriot Monoplane
The two steel tubes are 2 inches in diameter, 18-gauge, and about 4 feet 10 inches long. At their lower ends they are flattened, but cut away so that a 2-inch ring will pass over them. To these flattened ends are attached springs and wires which run from each tube across to the hub of the opposite wheel. The purpose of these is simply to keep the wheels normally in position behind the tubes. The tubes, it will be noticed, pass through the lower beam, but are sunk only 1/8 inch into the upper beam. They are held in place by sheet-steel sockets on the lower side of the upper beam and the upper side of the lower beam. The other sides of the beams are provided with flat plates of sheet steel. The genuine Bleriot has these sockets stamped out of sheet steel, but as the amateur builder will not have the facilities for doing this, an alternative construction is given here.
In this method, the plates are cut out to pattern, the material being sheet steel 1/16 inch thick, and a 1/2-inch hole drilled through the center, a 2-inch circle then being drawn around this. Then, with a cold chisel a half dozen radial cuts are made between the hole and the circle. Finally this part of the plate is heated with a blow-torch and a 2-inch piece of pipe driven through, bending up the triangular corners. These bent up corners are then brazed to the tubes, and a strip of light sheet steel is brazed on to cover up the sharp edges. Of course, the brazing should not be done until the slides GG, Figs. 27 and 28, have been put on. When these are once in place, they have to stay on and a breakage of one of them, means the replacement of the tube as well. This is a fault of the Bleriot design that can not well be avoided. It should be noticed that the socket at the upper end, as well as its corresponding plate on the other side of the beam, has extensions which reinforce the beam where the eye bolts or U-bolts for the attachment of the steel tape pass through.
Forks. Next in order are the forks which carry the wheels. The short forks JJ, Figs. 27 and 28, which act simply as radius rods, are made of 1- by 3/8-inch oval tubing, a stock size which was specified for the overhead truss frame. It will be noticed that these are in two parts, fastened together with a bolt at the front end. The regular Bleriot construction calls for forged steel eyes to go in the ends of tubes, but these will be hard to obtain. The construction shown in the drawings is much simpler. The ends of the tubes are heated and flattened until the walls are about 1/16 inch apart inside. Then a strip of 1/16-inch sheet steel is cut the right width to fit in the flattened end of the tube, and brazed in place. The bolt holes then pass through the combined thickness of the tube and the steel strip, giving a better bearing surface, which may be further increased by brazing on a washer.
The long forks FF, which transmit the landing shocks to the springs, are naturally made of heavier material. The proper size tubing for them is 1 1/8 by 5/8 inches, this being the nearest equivalent to the 14 by 28 mm French tubing. However, this is not a stock size in this country and can only be procured by order, or it can be made by rolling out 15/16-inch round tubing. If the oval tubing can not be secured, the round can be employed instead, other parts being modified to correspond. The ends are reinforced in the same way as described for the small forks.