Doug, I suspect that the length of the steering arm at the wheel would
have to be changed. This is a very common issue with the SUnbeam Tiger
sitting in my garage. The ackerman angles are truly farkled. As you
turn, the inner wheel turn some but the outer wheel turns more! Makes
for lots of oversteer. Thias all came about because Carroll Shelby was
in a hurry to get the Tiger back to Lord Rootes for production design.
Put the steering rack in the way wrong spot and then added angles tie
rod ends to cure the problem. Result...ok in a dead straight line not
worth a plugged nickle on a turn. Many things tried to fix. Only thing
is a new front end design.
All, regards front end design for an in-line streamliner. On a four
wheeled car in normal configuration, the front tires are separated by
the track of the front tires. And as has been stated, if you turn, then
the line drawn perpendicular to the wheel (or a line entending from the
spindle straight out) strikes the line drawn through the rear axle
(think of long extended axles). Then the outer wheel must turn in a
manner such that the line extended from the spindle meets the same
intersection point on the rear axle line as the inner wheel intersection
line. SOunds complicated but really isn't. Now I have not built or even
participated in the building of a liner with inline steering wheels. But
here is how I would do it. I would draw the line through the rear axle
and put the car's centerline on it. Then measure up to the centerline of
the rearmost steering wheel. Then scribe an arc down to the rear axle
centerline. Do the same for the front steering wheel. If you do this,
you will see that the front wheel turns less than the rear steering
wheel. This would I believe be a correct ackerman. Then I would fab up
the steering arms to make this happen. I could very well be wrong in
this however. It is my turn to be wrong this week... Unfortunately this
is really complicated by caster. In order to work perectly the
suspension would have to be straight up and down through the contact
patch without any heeling over due to caster or king pin offset.
Or you could run a bike...
mayf
DougOdom wrote:
>John Burk wrote:
>
>
>
>>Doug asked
>>
>>
>>
>>
>>
>>>How can you measure ackerman if you do not know the length of the steering
>>>
>>>
>>>
>>>
>>arms and the >distance they are apart?
>>
>>Doug , if the ackerman is correct the axis of each front wheel crosses the
>>axis of the rear wheels at the same point . If the left front is turned 1 deg
>>left and the wheel base is 10 ft the radius of that triangle is 573 ft . If
>>the front tread is 4 ft the right front triangle (10 x 577) is .0993 deg .
>>
>>John
>>
>>
>>
>>
>OK, Now if the ackerman is not correct after you measure it, what will
>you change to make it correct?
> Doug
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