Control arm/rocker ratio algorithm

[SvenPHX]

Hi,

My first post ... long time listener, first time caller so to speak. I am based in Phoenix, AZ and I am designing a racecar for personal entry into SCCA solo II type events, autocross, etc.

I am in the process of designing my front suspension which will comprise of non-parallel, non-equal length control arms and inboard coilover shock absorbers actuated by a linkage/bellcrank that is itself actuated by a pushrod connected to the lower control arm. Pretty classical design, I believe.

Anyway, my question regards if an algorithm exists to determine shock movement (inner rocker arm movement) based on lower control arm movement, actually it's probably lower balljoint travel relative to the ground. As my lower balljoint raises 1" from static the inner rocker pivot moves downwards in quite a predictable way, obviously, so it seems logical that an algorithm would exist.

Thanks!

-Sven

 

[GregLocock]

I doubt that a general, accurate, algorithm exists, unless your geometry is very straightforward.

The usual method is to draw the suspension at design, full jounce and full rebound, and measure it. This has the advantage of being pretty much foolproof, and highlights any sub standard clearances.



Cheers

Greg Locock

 

[SvenPHX]

Thank you. Ihave already started the modelling process using solidworks, which makes geometry changes quite trivial. The less trivial part seems to be making a model in such a way to actually take or identify measurements without using the 'measure' tool.

-Sven