Why is there a 3° variation in angles when calculating the Ackerman percentage?

[Reddy]

Hiii...
I hav caluclated my inner wheel lock angle(38.25°) and outter wheel lock angle(26.16) from formulae ...and I tried to caluclate for X degree rotation of my inner wheel how much my outter wheel rotates...ex:- at 20° rotation of inner wheel...17.7° of outter wheel ...nd at 38.25 I got outter wheel angle as 29.35° ...but actually that should be 26.16°, ryt?
Why this happens ??
And i reduced my tie rods length by 0.1inch on each in my calculations...I got the required outter wheel angle 26.16°..
But I can't reduce my tie rods lengths according to geometry...
If reducing tie rods length is d solution, thn how to satisfy geometry too??

 

[insightful]

If reducing tie rods length is d solution, thn how to satisfy geometry too??

Because, reducing tie rod lengths is not the solution. Ackerman geometry is mainly a function of the steering knuckle arm placement, i.e., tie rod end joint placement relative to the steering axis of rotation for the wheel. Since these axes are not vertical, the geometry gets complicated. If you're getting only 3^o deviation from true Ackerman geometry at full lock, you're doing well.

 

[Reddy]

Tq ..
3° varaiation in angles giving me 71% Ackerman .i.e..,less than true Ackerman..I didn't fix it for less than true Ackerman ...it came automatically... I don't know what makes in design