How to Make a Pulley System to Open a Box

Single Pulley

• 1

  Select a pulley block that can support the weight of the box lid you want to open. Suspend this from a solid support directly above the box. Use a ceiling hook as a support for light loads or an A-frame gantry for heavier loads.

• 2

  Find a piece of cord or rope that is twice as long as the distance between the pulley and the box. Verify it is strong enough to support the weight of the box lid and feed one end over the pulley.

• 3

  Attach one end of the cord or rope to the lid of the box. Pull the other end gently to take up the slack. Once the cord is tight, pull harder to lift the lid and open the box.

Double Pulley

• 4

  Select a pulley block that can support the weight of the box lid you want to open. Suspend this from a solid support directly above the box. Use a ceiling hook as a support for light loads or an A-frame gantry for heavier loads.

• 5

  Fasten a second, identical pulley block to the lid of the box. Find a piece of cord or rope that is three times as long as the distance between the upper pulley and the box. Verify it is strong enough to support the weight of the box lid.

• 6

  Fasten one end of the cord to the ceiling hook or gantry. Feed the other end around the pulley attached to the box lid and over the upper pulley.

• 7

  Pull the free end of the cord gently to take up the slack. Once the cord is tight, pull harder to lift the lid and open the box.