Join Date: Aug 2001
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Re: Are two Tie Rods better than one?
When I was first thinking about this issue I thought the same thing.
I figured it would not work unless the two sets of arms were exactly the same. And the two tie rods were the same length.
However, I was not sure.... So I did some research
My trusty (but dusty) Rigid body dynamics Text book proved to me that a 4 bar mecanisum having equal length shorter sides
(Ie the two steering arms connected to the same tie rod have to be the same lenght from knuckle pivit point to tie rod connection point) (they are, for both top and bottom tie rod)
with a single drive link
(the steering arm attacthed to the steering box) Is the drive link
Will keep the two oppisite (shorter sides) at the same angle.
I will admit that text books never make things totally clear. But I was pretty sure it would work, even if the steering arms were not the same length. But not totally sure. So I developed a modle.
I used a simple computer Drawing and rotated the drawing about the pivit points on the axle. The two tie rods with different length steering arms never changed lenght. Well that is all fine and good but for those that still don't believe. Here is a simple proof.
You know when you have a cardboard box and you open the top, and open the bottom it kind of flops down flat. Think of the part on the ground as the axle shaft, and the part oppisit it the tie rod. The two parts left are the steering arms. Now say you have another unfolded box. This one is not a rectangle but a box that has 3 different length sides. The to sides that are the tie rods are the same length (but not the same as the first box) the side on the ground that is the axle is the same lengh as box one. Put those two boxes together so that the pivits are the same. the boxes would be stacked on the ground top to bottom. Kind of making a long cardboard tunnel. Set the angle of box one and two differnt in ref to the axle tube box. Stick them together some how to make the whole system ridgid, and rotate the whole system about the pivit points. (knuckle pivit points) It will swing through an arc smoothly.
I am pretty sure two tie rods will work. This post has turned into a brain teaser.
I was just wondering what everyone thought of the idea of having two tie rods. I am not saying I am going to set my jeep up like this, I wsa just wondering what people thought.