In most modern house construction trusses are used instead of rafters. They come prefabricated and a contractor will often rent a crane for a day to sway the trusses into position.
Today’s paper crane uses cutting, gluing and braiding to make a crane with its own truss to lift.
3 colors of construction paper for the body, arm and tracks of the crane
1 piece of cardstock to mount the crane on.
2 craft/popsicle sticks
18 inches of yarn or cord
this pattern [download id=”31″]
Cut out the arm, body and tracks of the crane. Glue the tracks and the body to the cardstock as shown in the example below. Using a small piece of tape carefully wrap the narrow end of the arm to strengthen the paper, then secure the wide end of the arm to the body with a brad.
Break one of the craftsticks in half and break the curved ends off of the other one. Position the three pieces in the shape of a triangle to make a truss. Glue or staple together.
Cut the yarn into three equal length pieces and braid into a “chain” for the crane. Tape one end of the chain to the crane arm and one end to the top of the truss. Now the crane can lift trusses up to the top of the building.
Trusses take advantage of the properties of a triangle for their strength. Discuss how the weight of the roof is distributed by the triangles. You can visit the Construction Truck Preschool Pinterest Board for links to more information about trusses and cranes!