Wishbones attachment question !

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Wishbones attachment question !

Post by firasf1dream » Mon Jul 21, 2014 4:51 pm

hello guys,
i need to know please if the upper and lower wishbones in F1 moves ? and how is it attached exactly to the chassis ?
i marked the parts in the picture below and i numbered it 1,2,3

so about number 1: i need please to know (pictures if possible) how is it attached to the carbon fiber chassis and how is it configured for the needed settings ?

number 2 : is there any tiny spaces between this and where it is attached to the chassis that make is movable ?

number 3 : is this a cable that passes in the wishbone and make it able to be configured up and down by turning the screw ?
Image

marcush.
268
Joined: Tue Mar 09, 2004 3:55 pm

Re: Wishbones attachment question !

Post by marcush. » Mon Jul 21, 2014 5:05 pm

you have to understand that a moncoque is not just an empty hull but reinforced by bulkheads designed to carry the loads and spread them into the Chassis.
beneath you can see an example of how a wishbone fitting block could look ike it would actually require no big holes (apart from the mounting screws) and locate this Shells into cavities molded into the moncoque outer Shell.The actual load
is carried by the bulkhead behind
Image

and here a bare Chassis to Show the pickup Points:

Image
Last edited by marcush. on Mon Jul 21, 2014 9:06 pm, edited 1 time in total.

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Mon Jul 21, 2014 6:03 pm

aha nice picture ! so tell me: the bulkhead when i search for it, it says it's this shape that the nose is attached to it isnt it ?
so what else it does when it comes to structure and safety how is it made ? sandwich panel ?

and about the picture u showed me, this is exactly like in F1 cars ? and how is the wishbone level regulated ? is it just by the spring and dumper ?

FW17
189
User avatar
Joined: Wed Jan 06, 2010 9:56 am

Re: Wishbones attachment question !

Post by FW17 » Mon Jul 21, 2014 6:23 pm

Two types of joints are used

fixed and pin joint
The key component of the suspension are the wishbones, these "A" shaped arms connect the wheel assembly to the chassis. Thus they feed the loads from cornering into the chassis and control the suspension geometry. On an F1 car Wishbones are made from hollow carbon fibre teardrop profiles. Carbon fibre is chosen over steel as the component can be lighter, but also because the complex profiles are easier to make.
While it possible to have a completely carbon fibre wishbone, where the wishbone meets the upright and chassis the loads are so high, that it's easier to make these areas from titanium and have them bonded to the carbon fibre wishbone.
On a typical race car the point where the wishbone bolts to the upright of chassis is a spherical bearing, this allows the wishbone to pivot, but these are prone to sticking as they start to move. So often F1 designer will use a flexure joint, this is a thin blade of titanium or carbon fibre that bends to provide suspension movement, without the sticking. They are most often used on the front suspension where the wishbones are longer and are not subjected to the same heat as around the rear suspension.
Wishbones not only form part of the suspension but also the aerodynamics. Although the profile of the wishbone must be a simple symmetrical teardrop at no more than 5-degrees angle to the floor of the car. Even with these restrictions if you ran the simulation in CFD the car creates more force with the wishbone then without them.
Wishbones are not adjustable.

Image

The cable is the wheel tether, part of safety.

more here
http://www.f1technical.net/forum/viewto ... 7&start=15
Last edited by FW17 on Mon Jul 21, 2014 6:32 pm, edited 1 time in total.

thisisatest
17
Joined: Sat Oct 16, 2010 11:59 pm

Re: Wishbones attachment question !

Post by thisisatest » Mon Jul 21, 2014 6:24 pm

#3 is the wheel tether in case of it flying off the car in an accident.

edit: williamsf1 beat me to it.

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Mon Jul 21, 2014 8:20 pm

ok so the wishbones move into a limited amount which is defined by the place where joint are attached in the chassis ?
and the dumper come to define the settings ?

marcush.
268
Joined: Tue Mar 09, 2004 3:55 pm

Re: Wishbones attachment question !

Post by marcush. » Mon Jul 21, 2014 9:21 pm

go and read and build some knowledge .
wishbone is just there to constrain the wheel into limits of movement -no damping ,no springing Action ...more or less .
The blade type Suspension pickups are there for:
Installation stiffness
reducing parts Count (less parts ,less potential for failure,less weight)
aero

this is of course a very simplified view of reality -as soon as you incline wishbones in longitudinal driection not all spring Forces go through the pull or pushrod anymore -but thats the next can of Worms to swallow... so we leave this aside for the moment..

the bulkheads are not visible in the Pictures really .
Here is a older Picture of an early stage of monocoque construction with bulkheads already in place:

Image

The bulkheads are positioned strategically to stiffen Areas were loads are fed into the Chassis .Carbon fibre is very mediocre at taking Point loads so you´d better spread the Forces very cleverly into the structure to avoid premature cracks and local stiffness issues ....well.. this holds true for every material.. :)

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Mon Jul 21, 2014 9:41 pm

ok but now i am confused, searching for the bulkhead i found it's the part that the nose is attached to isnt it ?

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Mon Jul 21, 2014 9:46 pm

ow ! or is it the 2 barriers in the middle ?!

thisisatest
17
Joined: Sat Oct 16, 2010 11:59 pm

Re: Wishbones attachment question !

Post by thisisatest » Tue Jul 22, 2014 3:24 am

the horizontal walls are bulkheads. there can be more than one. it describes a type of part, not one single specific piece.

marcush.
268
Joined: Tue Mar 09, 2004 3:55 pm

Re: Wishbones attachment question !

Post by marcush. » Tue Jul 22, 2014 8:35 am

the regulations specify where you can put those bulkheads and theres even minimum requirements in Terms of dimensions

the forward end of the Chassis is usually a bulkhead as is the rear of the monocoque -but many Teams now choose to integrate the front and rear into the hull as a quasi continous shape ..not sure if you could say that this is a bulkhead still as it´s not a separate part ...but I think thats a bit nitpicky here..

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Tue Jul 22, 2014 3:26 pm

aha ok thanks a lot
just one more question : how is the nose attached from the bottom to the front bulkhead ? there is pins that goes in a horizontal way but how is it attached from the bottom ?

marcush.
268
Joined: Tue Mar 09, 2004 3:55 pm

Re: Wishbones attachment question !

Post by marcush. » Tue Jul 22, 2014 6:25 pm

firasf1dream wrote:aha ok thanks a lot
just one more question : how is the nose attached from the bottom to the front bulkhead ? there is pins that goes in a horizontal way but how is it attached from the bottom ?
the Pins -which are IKEA furniture inspired are just there to preload /tension the connection .All the loads fed into the nosecone are supported by other means of Fixation usually some sort of wedge type domes:

the Mercedes solution with those two shelves at the bottom of the monocoque are sure related and owed to the incident which cost Rosberg a very good result last year when all of a sudden the nosecone fell off because one Ikea fastnwer had failed (or was not fixed properly).

Image

firasf1dream
1
Joined: Fri Apr 18, 2014 8:26 pm

Re: Wishbones attachment question !

Post by firasf1dream » Wed Jul 23, 2014 9:18 am

ok about the ikea fastener, but i didn't get or i can't see how is it attached from the bottom ?

Thunder
Moderator
User avatar
Joined: Wed Feb 06, 2013 8:50 am
Location: Germany

Re: Wishbones attachment question !

Post by Thunder » Wed Jul 23, 2014 10:36 am

Here's what i could gather quickly from the McLaren:

Image
Image
Image