A Toy Derrick Crane With Clockwork Motor 230

All boys are interested in making things that "run," yet, surprisingly, few who have not had the possibilities demonstrated to them through the author's handicraft books and articles, think of utilizing clockwork for motive power. Those of you readers who have built the models described in The Boy Craftsman, Handicraft for Handy Boys, and Home-Made Toys for Girls and Boys, know that clockwork toys are among the best of home-made mechanical toys. You will not need to be told that the derrick-crane illustrated in Figs. 373 and 374 is well worth the time and effort required to make it.

One of the good points about using

Clockwork for Toy Motors is that any boy can obtain a set. The lifetime of the common form of alarm-clock is short enough to make discarded clocks plentiful, and all that a boy has to do, in case there isn't a worn-out clock at home, is to make inquiry of a friend or relative. Almost every one would be glad to have turned to account the clock that has become useless to him.

Figure 375 shows a clockwork converted into a motor for the toy derrick-crane. Besides removing the clock hands, it is necessary to remove the balance-wheel {A, Fig.

376) and the little lever (B) pivoted next to it. This is done to increase the speed of the clockwork. The wheel and pivot can be flipped out of their positions after the nuts which hold the frame together have been loosed.

A Toy Derrick Crane With Clockwork Motor 231

Fig. 375. - Detail of Clockwork Motor, Rubber-Band Belts, Spool Pulleys and Drums Fig. 376. - Balance-Wheel and Lever to be Removed from Clockwork Fig. 377. - Detail of Drum Frame Upright

The Pulley Wheel for belting up the clockwork motor to the toy is a short silk-thread spool (C, Fig. 375), fastened to the pivot from which the clock hands were removed. This spool may be fastened either with sealing-wax or solder. Lay the clockwork upon its back, center the spool on the pivot, and pour in the melted wax or solder; but be sure to protect the surrounding wheels by placing a piece of paper over them, especially if you use solder, otherwise you are likely to spill the solder on the wheels and unite them into a solid mass.

A Toy Derrick Crane With Clockwork Motor 232

For Pulley-Belts, buy a couple of rubber-bands 3/16 inch wide and 2 1/4 inches long (D, Fig. 375). The purpose of one of the rubber-band belts is to turn the drum on which the cable is wound that raises the derrick boom; the purpose of the other rubber-band belt is to turn the drum on which the hoisting-cable is wound. The belts run from the spool pulleys F joined to the spool drums E, to the spool pulley C on the clock work motor (Figs. 375 and 378). By the two-belt arrangement, one or both winding-drums can be turned at a time, by slipping one or both belts upon pulley C on the clockwork motor. When only one belt is connected up, the other is slipped over the nail I (Fig. 375) to lock the winding-drum which it turns. By giving the belt a half twist before slipping it over the pulley, as shown in Fig. 375, the drum will turn in the direction opposite to that in which it turns when it runs straight over the pulley; therefore, the winding and unwinding of the drums depend upon whether the belts run straight or are twisted. Five operations can be controlled. The cable can be wound upon one drum while the other drum is locked (Fig. 375), or it can be unwound, both cables can be wound or unwound simultaneously, and one cable can be wound while the other cable is being unwound. Also, both belts can be thrown off the motor pulley, and looped on to the nails I (Fig. 378), to lock the drums and allow the motor to run free.

The Winding-Drums are common thread spools (E, Figs. 378 and 379), the pulleys on their ends (F) are short silk spools. Nail the pulley spools to the drum spools with brads. Cut the axle for mounting the drums and pulleys enough smaller in diameter than the spool holes so the spools will turn easily (G, Fig. 379). The axles are mounted on supports H (Fig. 378), a pattern for which is given in Fig. 377. The axle holes are located on the pattern.