Creating an action wooden crank toy will combine the fun movements of a windup toy with the pleasures of woodworking. A simple crank and slider mechanism converts rotational movement into straight line up and down movements much like the action that drives a locomotive or the motor in a car. By working with thin pieces of balsa wood, a variety of interesting toys can be fashioned.
Cut out a crank similar in shape to the one shown in the illustration from a thin sheet of balsa wood using a craft knife. Make a hole near one end of the crank.
Cut out a shaft with a craft knife from the balsa wood sheet twice as long as the distance between the two holes. Make a hole near each end of the shaft.
Cut out a rectangle with a craft knife from the balsa sheet and make a hole in the middle near one end. This will serve as the slider and must be contained to linear motion. To do this fashion low retainer walls just slightly wider apart than the width of the slider and glue them to either a balsa wood or cardboard base. The walls should be double the length of the shaft and the slider.
Anchor the crank by cutting a hole for it through a piece of balsa wood the same height as the retaining walls. Glue wood squares that are equal in size to the retaining walls on either side of the crank and on both sides of the balsa wood.
Glue wood blocks to the base at a proper position. This ensures that the crank end with the hole is on a line with the mid space between the retaining walls, and is at a distance just slightly longer than the shaft.
Fasten the crank and the shaft together at 90 degree angles using wire strung through holes.
Fasten the other end of the shaft to the slider using wire strung through holes and place the slider between the retaining walls.
Turning the crank will now produce linear motion on the slider that can be used to shake a rattle or make a doll dance or power any number of back and forth toys.
The thicker the balsa used, the more sturdy the design will be, but cutting the material will be more difficult. Those skilled in woodworking can substitute hardwoods for balsa providing greater strength.
Always be careful cutting with a craft knife. Glue objects in a well ventilated space.