The simplest way to make a pulley is to find objects to represent each of its component parts. A pulley is made up of an object, a rope or string, a wheel, and a force. The string should be attached to the load and looped over a wheel, or spool, at around the midpoint. A string works by reversing the direction of the work load and, when pulled, lifts the load.
A pulley is considered one of many types of simple machines. Other simple machines include a lever, wheel and axle, and wedge. When more than one simple machine is used, the device is considered a complex machine. Simple machines are used to make work easier.
One way to make a pulley is to use a coat hanger with an empty thread spool attached to the horizontal bar. A string can be threaded over the spool and tied to a load, like a toy. Pulling or releasing the other end of the thread will cause the toy to go up or down. This type of homemade pulley is useful for demonstration purposes in a classroom.
To lift larger loads, it’s possible to make a pulley by using an old bicycle tire, a rope, a beam attached to a fixed object like a ceiling, and some old coat hangers. Once the tire is removed from the bicycle tire, the coat hanger can be twisted into an axle that fits through the center of the wheel. The wire can either be attached by two ropes at the ends and tied to the overhead beam, or it can be twisted into a circular shape big enough to encompass the wheel and then tied to the rope and attached to the beam. Another rope strung through the groove of the bicycle wheel and tied to the object at one end can be pulled by the other end to lift the object.
It’s also possible to make a pulley to help with very heavy loads, like pulling shingles up to a roof or moving items to the top floor of a multi-story building. In this case, it may be necessary to install a small boom crane from pipe or wooden beams as a support for the pulley system. For heavy loads, pulley systems can be purchased and mounted securely, keeping in mind that each additional pulley significantly eases the load. To make a pulley system for extremely heavy loads, it may be best to consult a professional for safety reasons.
