Fig. 163.—Fitting Wheels
Fitting Skid.—Steel-wire skids can be fixed to model aeroplanes as in [Figs. 162] and [162A]. The wheels can be obtained of any model aeroplane firm, and can be fixed to the machine as shown in [Fig. 163]. This would increase the weight of the machine, and more rubber may have to be used and the main planes adjusted to suit. Use No. 21 b.w.g. wire (steel).
Elevator Adjustment.—Elevators are sometimes fixed to the fuselage as shown in the accompanying sketch ([Fig. 164]), which shows it fixed above the spar. It is claimed that, in this position, the elevator is more efficient.
Fig. 165.—Fixing Struts to Biplane
Fig. 164.—Elevator Adjustment
Loading per Square Foot.—Generally speaking, the loading per square foot of supporting surface for rubber-driven models should not exceed 6 oz., nor be less than 3 oz., while to obtain good stability the ratio of machine length to span should be somewhere in the neighbourhood of 3: 2.
Fixing Struts to Biplane.—One very suitable method of attaching the inter-struts to wings of model biplanes, that admits of dismantling the model for packing, is shown at A ([Fig. 165]). A short length of brass tubing of ³/₃₂-in. bore is bound with fine florist’s tinned iron wire to the wing spar, the inter-struts being bent to the shape given at B, so that they spring tightly into the sockets. A simpler method is illustrated by C. Here the inter-struts are bent at right angles on the ends, bound to the wing spar, and soldered. Much will depend on whether a fuselage is one-or two-membered, but a frame attachment capable of adaptation to either is given by D and E. Wire crutches are bent to take the cross-section of the frame member or members, and fixed by binding and solder to the central inter-struts. Yet another method is shown at F, which is self-explanatory.
