how to find a rigs C.O.G..............

[bob1961]

i see lines drawn on pictures as to there c.o.g....how does one find there rigs c.o.g. by a picture....i'll have to get a good side picture of my rig if that will help ...............bob

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[engineerjoe]

i think the lines on the pictures you're reffering to is for showing the anti squat design of your suspension.

As far as wanting to know where your CG is, it's not really necessary. If you drive and flop over alot your CG probably too high for your terrain. If you think you're dragging your skid alot you might want to try raising it.

A good test of CG is to find the balance point of the rig up an incline or the distance your rear tire is away from a wall when climbing straight up it. My rig has the lowest CG I have seen and I can get the rear tires ~1/2" away from the wall

[Terranaut]

Pictures won't help you find you C of G, just looking at it and having a stab in the dark is just as good.

It's easy enough to find C of G, several simple techniques I can think of that are quicker to do than to explain. One involves hanging the rig sideways with two strings, mark a line on the side of the chassis between the strings, move the strings to different places and repeat. Where the lines cross.... X marks the spot.

Cheers.

[frdtrkguy]

There is a mathmatical method for finding the Center of Mass of a fullsize vehicle. I suspect it could be used for 1/10 scale. Its commonly used for traffic accident reconstrucion. I could look it up or it could probably be found online.

[hitman46mod]

Originally Posted by engineerjoe

i think the lines on the pictures you're reffering to is for showing the anti squat design of your suspension.

As far as wanting to know where your CG is, it's not really necessary. If you drive and flop over alot your CG probably too high for your terrain. If you think you're dragging your skid alot you might want to try raising it.

A good test of CG is to find the balance point of the rig up an incline or the distance your rear tire is away from a wall when climbing straight up it. My rig has the lowest CG I have seen and I can get the rear tires ~1/2" away from the wall

Um I think you have the topic confused. CG (center of gravity) GC (ground clearance)

[engineerjoe]

Originally Posted by hitman46mod

Um I think you have the topic confused. CG (center of gravity) GC (ground clearance)

your GC (ground clearance) is directly related to your CG (center of cravity)

i.e. if you lower your ride height, you lower your CG

I am not mixed up

my point was that there is no need to know that your CG is at 3.25" high, that is useless. Set up the rig based on the terrain you'll be driving it on.

[Terranaut]

Originally Posted by engineerjoe

Set up the rig based on the terrain you'll be driving it on.

Although there are easy ways to pinpoint the C of G, and some good reasons for doing that, I tend to agree with engineerjoe too.

Cheers.

[solomon7]

Basic Pythagorean stuff pretty much. Here's a link:http://www.longacreracing.com/articles/art.asp?ARTID=22
There are ways of lowering the CG (placement is everything) without lowering the ride height as well. Just have to be creative.

[oldhippie]

I just put a bolt in the vise and balance the rig on the bottom and the side and where the two spots intersect is the cog. I think you are supposed to do it without the wheels and axles to figure squat.....