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Design & Technology

Printing, finishing, packaging, and paper engineering.

Paper engineering

Mechanisms are used to provide movement in models, pop-up books [pop up book: A pop up book is a book with card mechanisms that pop or stick out as the page opens. ] and other products with moving parts.


A lever is a rigid piece of material that turns about a fixed pivot point called a fulcrum. An input force (the effort) applied to one end of a lever is transmitted to the other end of the lever to move the output force (the load).

Levers can be used to:

  • apply a force
  • change the amount of force
  • change the amount of movement
  • change the direction of movement

The fulcrum of a lever does not have to be in the middle of the lever. The position of the fulcrum changes how much the load will move and the amount of effort required to move it.


Linkages are mechanisms which allow force or motion to be directed where it is needed.

A reverse-motion linkage changes the direction of motion. By pulling (or pushing) the linkage in one direction, it creates the exact opposite motion in the other direction. If the fixed pivot was not central, it would create a larger or smaller motion in the opposite direction.

A parallel-motion linkage creates an identical parallel motion. By pulling (or pushing) the linkage in one direction, it creates an identical parallel motion at the other end of the linkage.

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