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davethemenace
10-12-2011, 11:03 AM
Hey All,

I know I am new to the forum and I have already read up "If you are new here, click here and read this first..." http://fsae.com/groupee_common/emoticons/icon_smile.gif

I have also read and searched in the forum. However, I noticed that there are not many links for Steering Design. I am in the process of designing steering mechanism for the car and needed some help so I ask this question in best possible English known to me. :P

1) How to determine the Steering Geometry with the Wheelbase and Track-width given? (ie how to find out length of rack, steering arm length and angle, tie rod length)

2) How determine the co-relation between the rack displacement and steer angle given the steering geometry?

3) How to know if the design will meet the requirements?

Kindly provide help or relevant links in this regard.

Thanks,

davethemenace
10-12-2011, 11:03 AM
Hey All,

I know I am new to the forum and I have already read up "If you are new here, click here and read this first..." http://fsae.com/groupee_common/emoticons/icon_smile.gif

I have also read and searched in the forum. However, I noticed that there are not many links for Steering Design. I am in the process of designing steering mechanism for the car and needed some help so I ask this question in best possible English known to me. :P

1) How to determine the Steering Geometry with the Wheelbase and Track-width given? (ie how to find out length of rack, steering arm length and angle, tie rod length)

2) How determine the co-relation between the rack displacement and steer angle given the steering geometry?

3) How to know if the design will meet the requirements?

Kindly provide help or relevant links in this regard.

Thanks,

woodsy96
10-12-2011, 10:33 PM
Most of the answers you seek aren't available online, but good text books will point you in the right direction. If you can get hold of Race Car Vehicle Dynamics by Milliken & Milliken, and maybe a Carrol Smith book such as Tune to Win, they will put you in the right direction.

1) Most of these questions will be answered through iterative process using a Suspension Kinematics program, such as OptimumK or Susprog3D.

2) The answer to your second question should be obvious: it depends on the length (and to some degree angle) of your steering knuckle on your upright.

3) Read the rules but try and get as much steering angle as possible.

davethemenace
10-14-2011, 12:02 PM
Thanks a lot!

DougMilliken
10-16-2011, 06:12 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">1) Most of these questions will be answered through iterative process using a Suspension Kinematics program...
</div></BLOCKQUOTE>
Since you are starting from zero, I recommend you take a little time to understand the basics. Software is not necessary to get started (and software often hides the fundamentals). Make a top view drawing (can be a sketch to start) of the parts in different positions. Calculate 2D angles and displacements (analytic geometry), iterate the drawing.

Maurice Olley (in our book, "Chassis Design", published by SAE) works through steering and suspension calculations "by hand", he used a slide rule. All the simple math is shown, ready to make your own spreadsheet.
-- Doug Milliken

jeffryder12
12-17-2011, 11:20 PM
Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radius.

Altair
03-07-2012, 10:44 AM
hey guys,

is it really important for our tie rod to pass through the IC always. i am not looking for 0 bump steer this time.