You don't have to be a carpenter to create your own toy car pulley. Even a novice craftsman can easily build this educational toy made of simple machines. Children enjoy playing with the apparatus while learning about the uses of the lever, inclined plane, screw, wedge, wheel, axle and pulley equipment.
Select three wooden blocks in descending sizes, the largest about the size of your hand and the smallest about 1/3 that size. Choose the large wooden block from which to build your car. Drill holes through the width of each end of the block about 3/4 inch in from the length of the extremities and 1/4 inch in from the bottom depth. Each of these two holes will hold an axle.
Slip a wooden dowel or metal rod through each hole you just created. The rods should fit loosely enough to rotate and should stick out beyond both sides of the wooden block to accommodate wheels.
Use thick rubber washers as tires, or wheels. Use washers whose centres fit snugly around the ends of the rods, or axles, and that have enough thickness to carry the weight of the car. If necessary, glue several washers together to increase thickness.
Screw one of the eyelets the into "front" of car. Tie one end of the string to the eyelet.
Screw the remaining eyelet into one end of small wooden block, or load, and tie the other end of the string onto this eyelet, connecting the car to the load.
Create a wedge by using your handsaw and cutting one block into a scalene triangle (a triangle with no equal sides).
Create an inclined plane by hinging two wooden planks, or levers, together. The width of the planes should accommodate the width of the car with wheels and axles attached. The hinge singe should allow for a 0 to 90 degree range of motion between the planks at minimum, if not 180 degrees. Use screws to attach the short ends of the wooden planks to the hinge.
Attach a small pulley to the end of one of the wooden planks. Do not attach it to a hinged end.
Place the inclined plane assembly pulley side up, with the same end sticking slightly over the edge of the table. Slide the wedge, longest side down, between the two levers of the inclined plane to stabilise and adjust the angle of the upper plane. Hold the car from the bottom of the incline and guide the string over the pulley, allowing the load to hang over edge of table. Let go of the car and allow the load to pull it up to the top of the incline all by itself. Adjust the steepness of the incline with a wedge in order to observe the varying effects of car mobility.
Adjust the weight of both car and load by adding metal washers, coins, etc. (You can drill a recess in the top of the car to serve as a compartment for such items.) Add open-ended rings, hooks or clips to the load-bearing side of the string. Adjusting weights and plane incline will yield different results, allowing children to study the utilities of simple machines and their energy output abilities.
These instructions are not for children. While children may enjoy being part of this building project, children should never use tools, such as a drill or handsaw or any other dangerous equipment, without the proper safety maintenance instruction, abilities and adult authorisation for using such equipment.