Whether you are making a toy car for fun or for a school science project, propulsion for the car can be achieved in a number of ways. You could use your hands to send the car racing down a track, attach a balloon propulsion method or create a pulley system. Creating your own pulley-activated toy car requires just a little bit of time and energy and since you may have most of the supplies around your house, little money to complete.
Use a drill to make two holes through the width of the largest wooden block. Place the holes all the way through the width of the block. Put one about 3/4 inches from one end and the other 1-1/2 inches from the other end. Center the holes in the depth of the block. This will create a place for the axles of the car.
Insert one axle into each of the two drilled holes. You can use a dowel rod or a metal rod. The length of the rods needs to be 5 inches long so that when you insert them, they stick out 1/2 inch on either side of the block. Turn the rods to make sure they are loose and can turn.
Place two rubber washers on each axle. These will be the wheels of your car. Choose washers wide enough that they support the car up off the ground. Place one washer on each protruding end of the axles. If the wheels are loose, you can use hot glue to attach them to the axles.
Paint your car with acrylic paint if desired.
Twist an eye screw in the front edge, the bumper, of the completed car. Feed a 36-inch piece of string through the eye screw and tie one end to the screw to hold it in place. Twist a second eye screw into the side of a second block of wood, approximately 5 inches by 3 inches by 1 inch. Feed the loose end of the string through the eye screw and tie it in place. This will be the load.
Cut a third wooden block with the same dimensions as the previous block into a scalene triangle. The exact dimensions are up to you, but all three sides of the triangle will be different dimensions. One example is 5 inches by 4 inches by 6 inches.
Make an incline plane. Cut two pieces of 1/2 plywood 5 inches wide. Make the length of one 5 inches and the other 6 inches. Place the pieces of plywood on the corresponding sides of the incline plane and hammer them in place. Place the wedge into of the centre of two plywood pieces so that when it is constructed you have a ramp. Attach a pulley to one of the sides of the plywood, opposite where the two pieces of plywood meet at an angle.
Place the incline plane on the edge of a table, with the pulley pointing up and the pulley end hanging over the table slightly. Feed the string from the car over the pulley so that the load block is hanging over the table. Hold the load block in place. Place the car as far away from the ramp as the string allows and then let go of the load block to allow the car to drive towards the ramp.