How Do You Build a Pulley for a Science Project?

To build a pulley for a science project, first cut three circles out of heavy cardboard, glue them together, slide a bolt through the center and wind with string. To make a sturdier pulley, thin fiberboard or plywood works well.

Instead of storebought pulleys for a science project, it is easy for a student to make her own. The only supplies needed are heavy corrugated cardboard, a compass to draw circles, scissors, a nail, strong glue, nuts and bolts and a wire coat hanger.

  1. Make the circles
  2. Use the compass to draw three circles on the cardboard. Two of them should have a radius of 1.5 inches. The third circle should be slightly smaller, with a radius of about 1 to 1.25 inches. Cut the circles out with sharp scissors. Three circles make one pulley, therefore if a pulley system is the goal, make more sets.
  3. Glue the circles together
  4. Use a sharp nail or the points of the scissors to punch a hole through the center of each circle. Place three circles onto the nail and glue them all together. Let dry.
  5. Attach the pulley to the bolt
  6. Once the glue is dry, remove the pulley from the nail and thread the bolt through the center hole. Cut a piece of wire from the hanger about 8 inches long, bend it and attach it to each end of the bolt. Place the nut on the bolt and tighten just enough so the pulley still spins freely.