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.
- Make the circles 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.
- Glue the circles together 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.
- Attach the pulley to the bolt 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.