Shifting Gears Connecticut Invention Convention http://upload.wikimedia.org/wikipedia/commons/thumb/1/15/2010-10-30_Geeste%2C_Moormuseum_032_%285207510676%29.jpg/800px-2010-10-30_Geeste%2C_Moormuseum_032_%285207510676%29.jpg Shifting Gears Connecticut Invention Convention www.ctinventionconvention.org

Parts of a Toy: Gears http://upload.wikimedia.org/wikipedia/commons/4/42/Clockworksapprentice.jpg

Parts of a Toy: Wheels http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Wheel_chair.jpg/448px-Wheel_chair.jpg

Parts of a Toy: Screws http://upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Ruuvit.jpg/800px-Ruuvit.jpg

Preparing the Gears Cut out the gears from the pieces of paper passed out by your teacher Each student should have several gears of multiple sizes

3-D Gear Models

Printouts

Moving the Gears Put a point on the gear and turn the gear all the way until the point is in the same place that it began. Has anything about the gear changed? Put two gears together of the same size. When one moves, does the other move in the same direction? Do they move the same distance? Put two gears together of different sizes. When one moves, does the other move in the same direction? Do they move the same distance? What is the relationship between the size of the gear and the distance that its spokes move?

Exploration https://woodgears.ca/gear_cutting/template.html Play with the gears. Try to understand how they move together.

Modeling In groups of 3-4 students each, model what you think is happening when you ride a bicycle with gears? What do the gears do? What happens when you shift a gear going up a hill? Going down a hill?

Discussion Present a 1-2 minute summary about your model to the group. Begin discussing each other’s models. Focus on your reasoning. What made you draw or write what you did? What parts of your models are accurate? Which need to be improved?

Reflection Write a 1 paragraph reflection about what changes you would like to make to your models? What information do you need to learn about to be more certain about your model? Did you gain any ideas from listening to your classmates’ models?