General sterning question


I was just talking to the girlfriend after a trip to Manchester museum of since and industry. after looking round the aircraft she asked a question that stumped me.

Some plains use cable to move the control surfaces do any cars use this system for the steering?

As far as I know there are no cars that use this system. Is this because it is against the rules to do so, in this country? As it strikes me as a good way to get round clearance issues with the engine and also any problems with a collapsible steering shafts and the like, also you could eliminate bump steer by running cables through the wish boan.

Fly by wire I believe is on the way into production. (It may already be in some cars Toyota Prius.)

Its electrical wire not a mechanical cable and sends an electrical signal from the steering wheel to a rack.

However it still has a mechanical linkage just in case

so thereticaly a mecanical wire system would be ok?

this is LCB anything is possible

For no other reason than it doesn't seem right to me, I would be suprised if a system like that could get through SVA/MOT etc.

I'm wondering if the cables on a plane are less subject to the stresses and knocks than a cars steering would be.

The car still has to steer well even after the odd altercation with kerbs etc.



Cheers

Mark

How strong is a steering rack made of steel.

Now how strong would a cable system be? to make it strong enough to turn a wheel (i'm assuming push and pull integrated into the one cable) you'll be looking at some pretty hefty cable & then where is the advantage.

If you're looking at two cables each 'pulling' then you'd have to have some pretty nifty way of taking the slack out.

I think umpteen years of development has come up with the best solution

Even if they have cables, smaller planes have helper springs and vanes on the moveable surfaces to help centre them again. Larger aircraft have hydraulics on the ends of the cables.
Your rotary solid steering shaft is much simpler for a car.
There is nothing stopping you using a system of UJ's or cogs to overcome your clearance issues.

boats use this system blake, its called morse or rideglide. works well on a boat but hey never seen it on a car

It would probably be perfectly ok - if you installed and maintained it to aircraft standards.

Good idea though - it has merit... all we need now is a clever beggar to work it all out!

hi,

some intreting reponces the system on a plain that inspired the question used two cables in tension and hence looked like it could be quite light.

Blake

The thing is, how often will the cable snap?
On aircraft everything tends to be tripled up for safety.
If a cable shifter snaps then you just pull over. If your steering snaps you might roll over or crash.
How often have you heard of a solid steering rod or UJ snapping?

Aircraft design is a little more complicated than most people like to think, If you look closely at the control surfaces they are designed with all sorts of extra cut outs and counter weights designed to "balance" the controls. Most light aircraft can be flown with your fingertips. My first car was a Fiat Punto and that felt as though it was laced together with cables and elastic bands.

as I have atualy been driving a car while the stearing has failed and luckaly I hit nothing im not looking to introduce another falure point but i do find it intresting to ask if there is any reason that sertan ideas have not been tryed.

If you go and see the london to brighton run, you will see lots of old crocks that have lots of different things controlling them like hand throttles for instance.
Cars have evolved to make life easier for the driver.
You can be sure that somewhere, someone has tried what you suggest.
If not, why not have a go yourself?