The Forktop Kite
This kite is given its name because its backbone is divided into two curved prongs at the top. It has the double advantage of being bow shaped, and possessing a large sail area. The operator will find that it will move in a lively manner. Correct balance and shape are essential for successful flying. These are achieved by paying careful attention to all the constructional details. It is one of the largest kites described in the book, consequently the bridle and kite line must be correspondingly strong. The backbone, A, is 3 ft. 6 in. in length. Use 3/8 in. square strip-wood, which should be straight and smooth, and free from knots or any other defect. Notch the ends as shown (Fig. 9) and with a fine fretsaw blade saw down from the top end to a depth of 6 in. This makes two prongs, which are bent to a fork shape. First, soak the prongs in water for about an hour. Then bind round the backbone just below the prongs with strong thread. This will prevent the saw cut from developing into a split. Now, gently but firmly prise the prongs apart, and insert a wedge at the top of the opening. Use a piece of stripwood 3/8 in. square x 1 in. Glue and nail it in place, and drill small holes to start the fretwork nails, which are 1/2 in. long.
The crossbar, B, is 3 ft. in length. Use split cane about 1 in. thick, or as an alternative, 1/4 in. square stripwood. The ends are grooved and two small holes are drilled through, 1/2 in. from each end. Following this, the crossbar is curved to a bow shape. If cane is used, apply dry heat, for example, a gas jet, whilst bending it. This will stop it splitting. Soaking for a while in water is recommended if stripwood is used. See the section on 'Methods' in Chapter 7. Details of the shaping are as follows. Take a length of good quality string. Thread it through one of the holes and tie it, leaving a 5 in. tail to the knot. Pass the string over the end of the crossbar and over to the other end, where it is threaded through the second hole. Applying firm pressure, bend the crossbar to a curve. To do this rest one end of it on the floor. Press firmly downwards, at the same time drawing the string taut. Bind the end of this once or twice round the crossbar and tie. The depth of the curve at the centre should be about 3 in. This bowstring has to withstand considerable strain so make sure that it is tough.
The next stage is to attach the crossbar to the backbone, 7 in. from the top. Two small anchor blocks, each measuring 1/4 in. x 3/8 in. x 1 in. are glued to the backbone on either side of the crossbar. The latter is then glued and also lashed in place with thin string. Smear the binding with glue to stiffen it. Treat all subsequent bindings in the same way. It is highly important that the joint be properly made, for upon it depends the firmness of the framework. The framework is now ready to be braced. Use thin string which is capable of withstanding considerable strain. Tie a length to the bowstring, making use of the 5 in. tail which has been left. Pass it over the top end of the backbone, bind it round the other end of the crossbar and tie securely. Check that the bracing is really taut. Next, tie a length of string to one end of the crossbar, pass it over the bottom end of the backbone, and pass round and tie to the end of the crossbar. The finished bracing should sound a musical note when plucked with the fingers. If stripwood is used for the crossbar, a reinforcing strip is used, C. This is 1 ft. 5 in. in length and is cut from 1/4 in. square strip-wood. This is placed between two small anchor blocks of the same wood, 1 in. in length, which are glued to the crossbar. The centre of the strip comes over the centre of the backbone. Bind the ends of the strip, and also the blocks, to the crossbar with thin string. A small stripwood bridge, D, is placed between the backbone and the reinforcing strip, and is held in place with glue and a small fretwork nail.
The bridle is attached to the backbone in the form of a loop. Tying points are shown in Fig. 9. Use stout string, 7 ft. in length. A small anchor block is glued underneath the bottom tying point to prevent the bridle from slipping down. The framework is covered with pure unbleached greaseproof paper, or better still, lightweight cotton material. It may be necessary to join two pieces of the material together to make the cover. Lay the frame upon the material and with a soft grade pencil, mark out the shape allowing a margin of 2 in. all round for overlapping, and cut out. Cut narrow V-shaped slits in the margin. The cover may be decorated at this stage. A bright bold design looks most effective. Small details are useless. A pleasing design is illustrated in Chapter 7 under the heading 'Accessories'. It is advisable to produce the design on a separate piece of paper if a paper cover is used, and then glue it in place. One of the proprietary brands of lacquer goes well on paper and is easy to apply. If a cloth cover is used, then either a paper pattern may be glued on, as above, or the design may be painted on direct, using fabric painting oil colours.
Apply glue to the backbone and the crossbar and lay the cover in place. If it is a paper cover, apply glue to the outer half of the margin, fold over the bracing strings and fasten down. A cloth cover is sewn down. Note that the cover is divided at the top by the prongs. Glue extra strips of material around these for strengthening. The kite line is attached to the bridle by means of a bowline knot and a reef knot. The line is generally located a little way above the centre of gravity. To find this, place the kite by its backbone upon the end of a stick. The point at which the kite balances is the centre of gravity. A tail is fitted which is about 7 ft. in length. Two tassels may be suspended on strings from the ends of the crossbars. The ends of the framework should be protected by strips of insulating tape. It may be said, by way of general comment, that this kite is of the traditional style which is a great favourite because of its satisfactory performance. To achieve the latter, however, it may be found necessary to make certain adjustments, such as altering the position of the line on the bridle, or increasing or decreasing the weight of the tail by adding or removing paper pieces.