Definition

[uws sae-a]

definition

[Claude Rouelle]

You just opened a can of worms....

This is the way the German DIN 70000 describes a roll center and the SAE definition is not far from that and I like it because it is the best I have found.

The suspended mass roll center is the point in the vertical plane which passes through the wheel center points at which transverse forces can be exerted on the sprung mass without the roll angle due to kinematics occurring.

The suspended mass roll center is therefore the point around which the suspended mass begins to roll when a lateral force acts. The reaction forces are absorbed between wheels (non suspended mass) and body (suspended mass) through the suspension: springs, antiroll bars and dampers.

In simple 3rd grade words: the roll center is a concept, not a physical point but if it was a real, material point it would belong to the chassis (call it body or suspended mass if you want) and if you would apply a lateral force at that point you would not see any suspension moving or any roll angle (possible tire roll angle is not taken into account here)

Note that this is a 2D definition. There is a front wheel and a rear wheel transverse plane but their is only one suspended mass CG.

Now lets' other people speak and lets'the dance start...

[Tim.Wright]

The truth is... there is no spoon

[Jay Lawrence]

Judging by your user name (uws sae-a) I'm assuming you are from UWS in Australia. I don't think UWS has an engineering faculty, let alone a FSAE team.

Judging by your inability to identify yourself, ask a reasonable question, and show some effort, I'm assuming your user name is a lie. Not a good way to start.

[MileyCyrus]

Jay,

UWS does indeed have an engineering faculty at their penrith campus, it was one of my considerations when I was leaving high school, though FSAE reputation pretty well was one of the deciding factors that led me to Wollongong.

It would also seem that UWS has previously looked at starting an FSAE team, with a student in 2007 planning to do that as a thesis, (http://fsae.com/eve/forums/a/tpc/f/1.../m/57810846931) and this could be the result of that effort.

...or the name could indeed be a lie. It's not like mine is...

[Jay Lawrence]

Yeah I know they used to be somewhat involved. My bad
Don't think they offer mechanical any more though

Sincerely,
Taylor Swift

[Big Bird]

Hi Joseph,

Please send us a message at SAE-A headquarters so we can include your team on our mailing list. You can contact me directly on geoff_at_sae-a.com.au

Welcome to the FSAE Oz community!

Cheers,

Geoff

[Claude Rouelle]

uws sae-a,

You always have more to lose and little to gain by not identifying your self. I think each person putting a post here should simply tell who they are and which organization they belong to.

In any face to face conversation or debate educated and/or courteous people introduce themselves before asking a question. It is in their own interest and the interest of the public listening to their questions.

For me a forum is not different.

Up to you.

[Charles Kaneb]

UWS SAE-A, please complete the following assignment.

Get ahold of the following books (purchased or by interlibrary loan).

"Prepare To Win" Carroll Smith
"Tune To Win" Carroll Smith
"Think Fast" Neil Roberts
"Engineer to Win" Carroll Smith
"Mechanical Design of Machine Elements and Machines" Jack Collins

Read through each of them carefully, with a notebook at hand. Make drawings and notes. Think about where each trick of the trade would help with a part of your design.