The next fab will determine just how well this little machine will handle on the road. Utilizing a fully adjustable front suspension requires a number of design considerations. For instance, where am I going to put the connecting points and how will they be constrained to move in the desired direction? How far will they be allowed to move? When it moves in the parallel plane will it move favorably in the horizontal plane? Without some means to model these opposing movements it is a matter of trial and error and most of the trial will be error. Allen Staniforth developed what he refers to as a string computer that utilizes card board and paper components scaled to size and constrained with brads and string in order to simulate movements of the front suspension in various configurations. I am sure this works well but I prefer to use a computer computer. This first photo shows a top view of the suspension. This will be a double A arm suspension so this shows the upper A arm. The bottom A arm would be located right below it. Why is it called an A arm? I wondered about this for a long time. It is because the arm is sort of shaped like an A. Can you guess why it is a double A arm suspension?
The next photo is a view from the rear. It shows exactly where to place the A arms on the front nose section we just built and locates the direction of the wheel in the Y Plane. In two dimensional drawings we refer to side to side dimensions as the X Plain and the up and down directions as the Y plain.
You can't tell it very well from this next photo but it shows the position of the wheel in 2" of bump. For instance this shows the position that the wheel assumes when you run over a 2" high bump in the road. The idea is to keep as much of the tire in contact with road surface as possible so as to maintain control of the vehicle. This is also important when turning a corner because the chassis assumes a position similar to the forces exerted from a bump when cornering. The computer shows that we gain only one half of a degree of negative camber in 2" of bump. Is this a good thing? Is it good, better or best? I don't believe from my limited knowledge that there is a perfect suspension. Anything you gain in one area you lose in another. At least this will eliminate a lot of what is referred to as bump steer. If you have ever driven a vehicle with limited suspension you will recognize this phenomenon as the way the steering wheel jerks in you hands when you hit a bump. I want the smoothest ride possible for my girls. Besides you can easily turn that half of a degree of positive camber into a more desirable negative camber with the adjustment that this design affords.
The next photo is a view from the rear. It shows exactly where to place the A arms on the front nose section we just built and locates the direction of the wheel in the Y Plane. In two dimensional drawings we refer to side to side dimensions as the X Plain and the up and down directions as the Y plain.
You can't tell it very well from this next photo but it shows the position of the wheel in 2" of bump. For instance this shows the position that the wheel assumes when you run over a 2" high bump in the road. The idea is to keep as much of the tire in contact with road surface as possible so as to maintain control of the vehicle. This is also important when turning a corner because the chassis assumes a position similar to the forces exerted from a bump when cornering. The computer shows that we gain only one half of a degree of negative camber in 2" of bump. Is this a good thing? Is it good, better or best? I don't believe from my limited knowledge that there is a perfect suspension. Anything you gain in one area you lose in another. At least this will eliminate a lot of what is referred to as bump steer. If you have ever driven a vehicle with limited suspension you will recognize this phenomenon as the way the steering wheel jerks in you hands when you hit a bump. I want the smoothest ride possible for my girls. Besides you can easily turn that half of a degree of positive camber into a more desirable negative camber with the adjustment that this design affords.
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