Cita
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| posted on 25/4/04 at 05:38 AM |
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Swing axle
Hi Guys,
Has anyone any idea if the steering "swing axle" principle has been used on "modern" cars (ATV's-Buggy's etc...)
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It would deal with common problems on conventional steering upsets like scrub radius-Ackerman etc..I dont know if it even is feasable, as i didnt give
the shock absorbation any thought yet but IMHO perhaps there are some possibilitys albeit not for the Sevenish car perhaps.
I'm building a single seat hillclimber ( at least that's the intention ) and being a tightarse,i'd like to do it as cheap as
possible.The light weigth of this car perhaps could do with a simple steering concept as the swing axle.
My "guesstimate" is that my car would have an all up weigth including driver of about 250 Kg's.
Anny comment or is this idea TO STUPID to waste time on ('would not surprise me ! )
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britishtrident
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| posted on 25/4/04 at 06:18 AM |
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What do you mean by "steering swing axle" normally swing axle is a single suspension wishbone pivoted near the centre line of the car
with the wheel attched to the other end as used by Imps, Davrians, VW Beetle, Formula Vee single and Triumph Heralds.
The swing axle works well in off road apps but on hard surfaces because of jacking effects the roll centre need to be lowered almost to ground level
to get it to work and the suspension travel limmited by hard springs to prevent excessive camber change under heavy braking. It is also more
difficult to use in a single seater type chassis and maximum grip will be less than a double wishbone layout.
So the simple answee is no -- its easier cheaper and lighter to use double wishbones , Triumph Herald front suspenson is generally regarded as the
lightest road car front end parts and have been used on home built single seaters for the best part of 50 years.
[Edited on 25/4/04 by britishtrident]
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Cita
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| posted on 25/4/04 at 06:39 AM |
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Thanks for the reply british....As usual,i have problems explaining things in my own language let alone using a foreign language!
By swing axle i meant like it was used in the ancient horse carriage!
The whole single axle with both wheels pivots around one single point.
As said before it probably is even to stupid to waste time on.
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britishtrident
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| posted on 25/4/04 at 06:58 AM |
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Usually called carriage steering --- no won't work, leaving all the other problems out brake reactions would cause such severe steering kick
back that it would be impossible to steer it.
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Cita
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| posted on 25/4/04 at 08:04 AM |
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Would care to explain this a little further please?The kick back of the braking force?
Thanks !
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NS Dev
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| posted on 25/4/04 at 08:16 AM |
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As britishtrident says it will not work, the kickback in corners would make steering impossible, plus it would not be light anyway by the time you had
reinforced the chassis in one place enough to restrain the axle.
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Peteff
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| posted on 25/4/04 at 09:12 AM |
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You don't have normal steering geometry with a carriage axle on a central pivot so when it turns one wheel is effectively ahead of the other.
It's like the kid's trolley principle. You could do away with the steering rack and use a rope though.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Cita
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| posted on 25/4/04 at 12:56 PM |
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I thought the carriage steering IS the "normal geometry" for steering a vehicle and all the others were derived from this.
Its the only concept in wich both wheels that do the steering are on a perfect line to the center of the circle a car makes.
No scrubbing of the tires-no Ackerman but i do understand (i think ! ) what you guys mean.
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