Locating COG in 3planes

[chassis 33]

Can anyone offer any advice on locating the position, most specifically the height of the COG for a car. The position in the front back and left right is easy enough, but height?

Regards
Iain

[splatspeed]

if you can hang the car from a single point

the plumb line will go throught the centre of gravity

do this 2 - 3 times you have the centre point

not really easy to do unless you have a kit os something with a frame

[jwb]

This is not easy. There are 3 ways.

1) Put solid links on one side of the suspension to replace the springs. Then lift up one side of the car until you reach a balance point. The C of G lies on a vertical line from the contact point with the ground. If you have equal left right weight distribution the C og G will be in the middle of the car.

2) Corner weight the car. This gives you the front to back placement. Now lift one end as high as you dare still with corner weight scales. Note the hieght and weight distribution change. This will give you the C of G hieght.

3) Estimate.

Like I said not easy.

John

[Sam_68]

Basically as JWB says, but Allan Staniforth's 'Race & Rally Car Source Book' gives diagrams and formulae for working it out, IIRC.

E-mail me via my profile, and I can scan it for you (though may take a few days - about to go away for the weekend).

Gatting any degree of accuracy is quite difficult, though, so TBH, I usually just 'guesstimate' it.

[Mr Whippy]

Try here

http://forum.rscnet.org/showthread.ph

Interesting analysis...

Dave