Force and motion
Pop-ups
11. The Peek-a-Boo and the Hand-waver
Overview
This lesson introduces two new constructions, each of which uses an angle-fold in combination with a parallel-fold. In the Peek-a-boo, the motion of the angle-fold is hidden by the parallel-fold, so it appears to “come from nowhere.” The Hand-waver uses a series connection to move the angle-fold so the action is on the side of the page, not along the gutter. These two constructions are the basis for many of the pop-ups in commercial cards and books.
Procedure
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Make a Peek-a-boo. Provide each student with a Peek-a-boo template and show them how to make a Peek-a-boo. Provide time for them to explore what this construction does and how it moves.
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Make a Hand-waver. Provide each student with a Peek-a-boo template and show them how to make a Hand-waver. Provide time for them to explore what this construction does and how it moves.
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Peek-a-boo vs. Hand-waver. Ask students to compare these two constructions. They can use the Worksheet to record their findings. See a video exploring similarities and differences. A good way to compare them is to make a system diagram of each one.
Outcome: Each construction uses both a parallel-fold and an angle-fold. In the Peek-a-boo, the two pop-ups are in parallel, while in the Hand-waver the angle-fold is in series with the parallel-fold. As a result, the Peek-a-boo produces up-and-down motion along the gutter, while the Hand-waver uses the parallel-fold to move the motion to the middle of the page. -
Finding hand-wavers and peek-a-boos. Provide commercially made pop-up books that have these constructions. Students should look through these books to see how professional paper engineers have used the same constructions they have just made.
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Extensions. Here are some experiments and design challenges: How long can the Peek-a-boo’s flag be?
- How long can the Peek-a-boo’s parallel fold be?
- How can you make a Hand-waver that works like a bird with two wings, both on the same page?
- How can you make a Hand-waver that works like a turtle with four legs, two on each page?
Peek-a-boo Template
Hand-waver Template
Peek-a-boo & Hand-waver Worksheet
Troubleshooting
Students may have trouble seeing the angle-fold in the Hand-waver. See a video that shows where the angle-fold is located, by making a similar angle-fold from a separate piece.