Steering a Car: Investigating the Forces of Rotation

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Discussion Overview

The discussion revolves around the forces involved in steering a car, particularly focusing on the gyroscopic effects of spinning wheels and how they influence the ability to rotate the wheels for steering. Participants explore the relationship between applied torque and resultant rotation while considering constraints on movement.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether the gyroscopic effect of spinning wheels creates a force that opposes the rotation needed for steering, seeking to quantify this opposition.
  • Another participant suggests that the resistance to turning the wheels includes both the gyroscopic effect and additional resistance from the steering system's geometry, which tends to return the wheels to a straight direction.
  • A participant expresses concern about understanding the relationship between the torque applied on the X axis and the resulting rotation about X, while keeping Y constrained, noting their background in electrical engineering rather than physics.
  • A later reply references historical aircraft design to draw parallels with automobile steering dynamics, suggesting that similar gyroscopic effects may influence vehicle behavior, particularly in terms of directional bias.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the specifics of the gyroscopic effect's influence on steering, and multiple competing views regarding the nature of resistance and its implications remain present.

Contextual Notes

Participants acknowledge limitations in their understanding of the gyroscopic effects and the complexities involved in quantifying the relationship between torque and rotation, particularly under constrained conditions.

Who May Find This Useful

This discussion may be of interest to individuals studying vehicle dynamics, physics students exploring rotational motion, and engineers considering the implications of gyroscopic effects in mechanical systems.

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TL;DR
Questions about steering a spinning wheel. Does gyroscopic force oppose me?
In a car we turn the wheels to steer. The wheels however are spinning about their axis of rotation when the car is in motion. Does the revolving motion of the wheels cause a force that opposes trying to rotate the wheels around the other axis to steer? How much opposition is created?

gyro_illustration.JPG


Here's an image to illustrate. Suppose the wheel is quickly spinning about Z. I want to rotate the wheel about X to steer my car. I will not allow any rotation about Y. How hard is it to rotate the wheel about X?
 
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Spinning the steering wheels in the air could give you the actual resistance of the gyroscopic effect.
When rolling on the road and steering, there is additional resistance from the geometry of the steering system, which is built into make the wheels to tend to come back to a straight direction by themselves.

The gyroscopic effect depends on the rotational speed and moment of inertia of the tire.
 
So I'm just concerned about the resistance to turning the wheels due to the gyroscopic effect. To say it more succinctly, I need to know the relationship between the torque I apply on the X axis and the resultant rotation (speed, acceleration) about X all while Y is constrained so it cannot rotate that way. I know the mass of the wheel, its moment of inertia, rotation speed of the wheel etc.

This is out of my area of expertise (I'm an EE not a physicist).

[Post edited by a Mentor]
 
Last edited by a moderator:
cccc said:
Summary: Questions about steering a spinning wheel. Does gyroscopic force oppose me?

Here's an image to illustrate. Suppose the wheel is quickly spinning about Z. I want to rotate the wheel about X to steer my car. I will not allow any rotation about Y. How hard is it to rotate the wheel about X?
Wow, my "google-fu" has slipped big time---WW memoirs mention this effect yielding a "preferred direction" for aircraft turns; https://ww2aircraft.net/forum/threads/the-torque-roll.21319/ . And, P-38 was designed to prefer neither direction (counter-rotating props) https://en.wikipedia.org/wiki/Lockheed_P-38_Lightning .

I would expect automobiles to exhibit similar biases; perhaps the CCW tracks in the northern hemisphere?
 

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