Lesson 2 Preparation: Model Dog Door

This video demonstrates the how to prepare the model dog door for the YES Unit: Engineering Magnetic Dog Doors, Lesson 2
With the paperboard box laid flat, use a pair of scissors to cut off all the top and bottom panels except the large 4" x 4" flap top, which will become the door. Save all of the scrap box pieces that you cut off!
Cut off the thin panel on the end of the flap top (this is the narrow part that would normally tuck into the box).
Bend the sides of the box into shape.
Use a long piece of masking tape to secure the thin panel to the opening of the box opposite of the fold. It should be taped flush with the corners of the box so that the door can close.
Place the box on top of the Dog Door Scene so that the door swings open toward the dog kennel.
Use at least two long strips of masking tap to attach the door to the scene.
To reinforce the doorframe:
Fold the 2" x 12" strip of cardboard at 4" and 8" to create three equal 4" sections along the strip.
Holding this strip in an "upside down U" shape, slide the strip into the door frame to reinforce the top and sides of the box.