What is a design plan? Grade 8 Science IB J.Kelly

Draw a pair of scissors I’m sure most of you drew scissors that look something like this.... These are in fact scissors... But if I asked you to draw a design plan of scissors this drawing would be wrong.

The Design Plan The design plan shows in a simplified way the elements that make up an object or device and explains how they work In other words, your scissors drawing is way too artistic!!!

What to include in a design plan? The parts represented in different colors The name of the parts The movement that each part does The forces Any guides or links Indirect link: there is a linking component (glue, velcro, screw, staple, rivet, tape, nails) that holds two parts together Direct link: two parts are held together WITHOUT a linking component

Other Design plan rules Lines should be made with a ruler 2 parts that come together should be illustrated in 2 different colors Respect proportions of the object but it doesn’t need to be made to scale or measure

Symbols for Force and Motion Unidirectional translation tension Bidirectional translation compression Unidirectional rotation torsion Bidirectional rotation shearing Helical

Symbols for Links

Your Turn On a separate piece of paper, attempt a design plan of a pair of scissors. When you are done, come up and show Ms.Kelly

Design plan for a pair of scissors

A Design Plan for a pair of scissors Free in rotation and fixed in translation Upper Blade F Shearing Paper F 10 Pivot F Lower blade Bidirectional rotation The Components (parts) Movements Forces 10