# Spike Prime - Fractions with Gears

From RoboWiki

## Let's begin

Fractions...

## Build

Model:

Pictures:

Building instructions:

- Fractions with Gears - version 1 - Basic (PNG)
- Fractions with Gears - version 2 - Rotated Gear Frame of v2 (PNG)
- Fractions with Gears - version 3 - Even More Slow (PNG)

Download building instructions:

- Fractions with Gears v1 - basic (pdf)
- Fractions with Gears v2 - Rotated Gear Frame of v1 (pdf)
- Fractions with Gears v3 - Even More Slow (pdf)

Download stud.io model:

- Fractions with Gears v1 - basic (stud.io)
- Fractions with Gears v1 - Rotated Gear Frame of v1 (stud.io)
- Fractions with Gears v3 - Even More Slow (stud.io)

...description...

Connections:

- motor - B
- light sensor - A

## Programs

Download:

...description...

## Measure, analyze, think

- Make your own recording
- Perform experiments with your model and discuss in your group what has happened.

## Explore and modify

- Pick one of the three versions, build it
- Make your own drawing of the gear systems (i.e. on paper)
- Write down the numbers of teeth on each pair of the gear wheels
- Figure out the ratio of each pair of gear wheels
- Make or calculate your guess about the final ratio of gear wheels
- Perform measurement with the model and program and compare
- Try to invent some other combinations of gears, repeat the whole procedure with them (this can be an alternative project for an advanced group instead of the above)
- Could you list all the possible combinations using these 8 gear wheels that could be built?

## Present

- Think about a manual transmission in cars, how does it work? And how does automatic transmission work?
- What do fractions have to do with the car transmission?
- Is it only the speed of rotation that is being changed in the gear box? What else?

## Additional resources

- Download: Fractions with Gears - all media files