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Thanks and Regards

Rana Basheer

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- Thread starter ranabasheer
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- #1

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Thanks and Regards

Rana Basheer

- #2

tiny-tim

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I am trying to fitgure out the turning radius of a simple car with front wheel steering based on the velocity difference between the front wheels.

Hi Rana! Welcome to PF!

I think the turning radius depends only on the

I expect you're thinking that the outer wheel has to go further than the inner wheel, and so must go faster … but I think there's some sort of tracking arrangement on the front axle so that that

Anyway, imagine a three-wheeled car, with only one front wheel … it still turns, doesn't it?

- #3

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He is referring to the purpose of the differential in the car. Basically that the outer wheel (wrt the turn) must turn faster than the inner wheel and this relationship or ratio of the two speeds is a function of the turning radius of the car.

It can be easily shown that

wt * rt = ww * rw

and

rt = ro - wb/2, rt = ri+wb/2

where:

wt = angular velocity of the car

wb = wheel base of the car (width)

rt = radius of the turn

ww = angular velocity of the wheel (wo,wi as outside and inside)

rw = radius of the wheel

ro = outside radius of tire

ri = inside radius of tire

With a little coaxing and simple algebra you get this:

rt = [tex]\frac{-Wb}{2}[/tex] [tex]\frac{wi+wo}{wi-wo}[/tex]

It can be easily shown that

wt * rt = ww * rw

and

rt = ro - wb/2, rt = ri+wb/2

where:

wt = angular velocity of the car

wb = wheel base of the car (width)

rt = radius of the turn

ww = angular velocity of the wheel (wo,wi as outside and inside)

rw = radius of the wheel

ro = outside radius of tire

ri = inside radius of tire

With a little coaxing and simple algebra you get this:

rt = [tex]\frac{-Wb}{2}[/tex] [tex]\frac{wi+wo}{wi-wo}[/tex]

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I appreciate your help. I never looked at that way. I will test your equation on my RC car and let you know how accurate my turning radius are.

- #5

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i jus read ur post cos i had the same question.. now can u explain how did u derive it.. ? cos according to my calculation rt= rw - (Wb/2)(wi+wo)/(wi-wo) but urs say differently.... lemme know how u got the equation.

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