Take a thin metal sleeve—this is merely a hollow tube of aluminum or brass open at each end—8 inches long, and slip it over either the tongued or grooved end of one of the frame timbers. It is well to have the sleeve fit snugly, and this may necessitate a sand-papering of the frame pieces so the sleeve will slip on.
Push the sleeve well back out of the way. Cover the tongue thoroughly with glue, and also put some on the inside of the groove. Use plenty of glue. Now press the tongue into the groove, and keep the ends firmly together until the glue is thoroughly dried. Rub off the joint lightly with sand-paper to remove any of the glue which may have oozed out, and slip the sleeve into place over the joint. Tack the sleeve in position with small copper tacks, and you will have an ideal splice.
The same operation is to be repeated on each of the four frame pieces. Two 20-foot pieces joined in this way will give a substantial frame, but when suitable timber of this kind can not be had, three pieces, each 6 feet 11 inches long, may be used. This would give 20 feet 9 inches, of which 8 inches will be taken up in the two joints, leaving the frame 20 feet 1 inch long.
Installation of Motor.
Next comes the installation of the motor. The kinds and efficiency of the various types are described in the following chapter (IX). All we are interested in at this point is the manner of installation. This varies according to the personal ideas of the aviator. Thus one man puts his motor in the front of his machine, another places it in the center, and still another finds the rear of the frame the best. All get good results, the comparative advantages of which it is difficult to estimate. Where one man, as already explained, flies faster than another, the one beaten from the speed standpoint has an advantage in the matter of carrying weight, etc.
The ideas of various well-known aviators as to the correct placing of motors may be had from the following:
Wrights—In rear of machine and to one side.
Curtiss—Well to rear, about midway between upper and lower planes.
Raich—In rear, above the center.
Brauner-Smith—In exact center of machine.