Unit 2 - Gear Ratios and Drive Trains

Unit Objectives

This unit teaches students about the various gears available in a VEX robotics kit. They will understand how to calculate a gear reduction and how to apply these calculations to manipulate the speed of their robot.

Unit Teacher Notes

Click here to download teacher notes for Unit 2

Lesson 2.1 (60 minutes)

This lesson will teach students about gears and the trade off between speed and torque as it relates to drivetrains.

Outcomes

  • Identify the different types of gears
  • Explain the difference between speed, power and torque and vary the gear ratio (and the mechanical advantage) in a system, which gives them the versatility necessary to accomplish whatever work needs to be done.
  • Demonstrate the correct use of the calculations needed to choose a gear reduction for either high speed or low speed.

Lesson 2.2 (60 minutes)

Students will apply their newfound knowledge of gear reduction to calculate the distance that a robot travels based on the input speed of the robot and the wheel size.

Outcomes

  • Describe the relationship between radius, diameter, circumference, revolutions and distance for a wheels

Lesson 2.3 (420 minutes)

Students will apply their newfound knowledge of gear reduction to calculate the distance that a robot travels based on the output speed of the robot based on different gear reductions.

Outcomes

  • Analyze the features of their robot and identify/synthesize how to change them to get different results for high speed or low speed
  • Graph the results of their experiment in a meaningful way and discuss situations where the results did not follow the expectation.

Quiz (30-60 minutes)

Quiz on the unit

Outcomes

  • Check for Understanding