# Steering Wheel Radius - 2 Wheels

1. Oct 21, 2008

### 2know

On a Go-Kart you have two independent steerable front wheels that can be adjusted to steer at different rates. What I am trying to figure out is a formula I can use, converted to degrees or MM, to give the turn angle each wheel must achieve to turn the kart and not create mutual drag and binding?

Example:

The Kart is turned to the right. The left wheel turns 5 degrees right (or, say, 5cm right measured 1 foot in front of the wheel). How many degrees (or, MM) will the right wheel turn to create an arc that will parallel the left wheel. Obviously the right wheel will turn more than the left because it arcs a smaller circle. I just need a very simple formula to deduct this, "wheel parallel" for all angles. I have a device that will measure wheel movement in mm 1 foot in front of the wheel. Intuitively the answer will depend on wheel track width also.

thank you,

2know

2. Oct 23, 2008

### dodo

Time to speak of what I don't know.

It occurs to me that the main difficulty is not knowing the radius of the curve your kart is taking. But the driver sees it, makes a quick estimate, and turns the steering wheel accordingly.

So suppose you model the curve radius R after the wheel turning angle w, say, R = f(w) = k/w for some constant k (you can refine your model later). Now you set the outer wheel tangent to a circle of radius R, and the inner wheel tangent to a circle of radius R-d, where d is the distance between wheels.