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A scissor lift

Converting Motion With Linkages

Linkages are a fundamental part of how machines are designed because of their ability to create such a wide variety of output motion. Linkages can also change the direction of a force. The picture above shows a scissor lift which uses multiple scissor linkages. A scissor lift is often used to raise or lower people. In order for a scissor lift to raise, force is applied to the outer beams at the bottom of the lift. As force on the beams at the bottom pushes them closer to the center, the lift raises. This is a great example of how a linkage can change the direction of a force. In this case the linkage was again a scissor linkage like the Grabber's, but the force was generated by a motor instead of by the user squeezing the bottom beams.

  • Build Expert: explain how a platform might be added to the top of the Grabber to create something similar to a scissor lift.

  • Recorder: sketch and explain the design you decide on in your engineering notebook.