Lesson 2: Stability & Return-to-Center
Duration of Days: 3
Lesson Objective
SWBAT:
Identify Positive and Negative Caster on a vehicle's front spindle.
Explain the relationship between Caster and "steering effort" (how hard it is to turn the wheel).
Why is it easier to ride a bicycle "no-handed" than it is to push a shopping cart in a straight line?
What happens to the driver's control if the Caster is set to zero?
Caster, Steering Axis, Trail, Stability, Pivot, Spindle
CT-CTE.TRANS.D.15: Identify steering system components.
DOK Level: 2 (Application)
Students focus on Caster. The purpose is to understand how the tilt of the steering axis provides "straight-line stability" and allows the steering wheel to return to center automatically.
Misconception: "Caster affects how the tires wear out."
Correction: Caster generally does not cause tire wear; it primarily affects the "feel" and stability of the steering.
Support: Use a shopping cart wheel (caster) to show how the wheel always follows the pivot point.
Extension: Calculate the "Mechanical Trail" based on a specific caster angle and wheel diameter.
Students compare the caster angles of two different race chassis and predict which one will be "twitchier" at high speeds.