Front Wing Cores

[prepel]

What type of expanding foam do f1 manufacturers use in their front wing construction. Would it be the same as Dallara F3 front wing.

[Steven]

Hi and welcome.

In Formula One, as far as I know, front wings are nothing but carbon fibre, the front wing adjuster mechanism, some aluminium parts to connect flaps and often ballast inside the central part of the front wing.

Can you explain a bit what you're point at?
Do you mean the material that is used to create the moulds for CF production?

[Giblet]

The rear wing endplates contain foam, but not the fronts? I would think thicker parts could have foam cores to save weight but I am only speculating.

[scarbs]

Rohacell is the foam typically used in wing or wishbone construction, I expect this carries through to other formulii too.

[Belatti]

I had to do a CF rear wing for a sport prototype. I had no experience, nor autoclave.

I designed the wing profile and send it to a guy who can extrude expandable polystyrene. Then, "CF wrap up", laquer finish and voilá. Adding the supports was another question...

Just an idea for someone who might try to build one.

[prepel]

Thanks all,

Scarbs, is Rohacell a 2 part mix or does it have to be shaped and then wrapped up. I am trying to get away from wrapping if possible.

[747heavy]

maybe this helps

http://www.rohacell.com/product/rohacel ... fault.aspx

I don´t think, that anyone (in F1) uses an "expanding", two component foam, because by doing so, it would be difficult to control the density of the foam core, across the wing and therefore the mechanical properties.

You will need a mould to produce a wing with a good surface finish - IMHO

[marcush.]

the general idea is to machine a core from rohacell with an oversize to crush it somewhat in the manufacturing process .
although I have NO experience of doing this a lot of people have assured it is done this way and still raise my doubts how this would lead to a repeatable production process.
The idea for sure is to work with film like strips of resin that are brought into the mold after tacking the carbonfibre to the mold surface ,the rohacell core crush is used to firmly press the filaments and resin films towards the shape of the mold during the curing process.The use of film material and (prepreg)carbonfibre will enable you to have a minimum of resin content in the part,wich is mandatory for weight and strength.
All wet type laminating will lead to immense amounts of resin soaked into the core material and no real control of resin content.Wet layup is unsuitable for anything in CF work apart from lowest level panels and definitely not F1 and generally parts that have to have the CF looks .CF does not like wet layup methods and all possible advantage of the material is sacrificed with wet layups.
the methods are prepregs or film type resin systems or resin infusion processes ..
also RTM ....production volumes ruling out maybe the RTM direction for the cost of tooling.

[prepel]

I Have made a front wing, 2 cf halves and used a 2 pack expanding filler. this filler similar to what a seat is moulded from. Initially was looking for a more dense foam as it worked quite well but the wing did bend under high download forces.
I use the wing on a 2004 f3. I use this wing at low downforce circuits. I can strengthen with cf to eliminate this, but a simple start was a denser filler. i dont have acces to machine the core, so this is why i am going down this road. It is cheaper for me to build it this way, or as my wife says, stay on the track.

[marcush.]

Core density will not really .. it`s more brittle it will just break the core I´d think.
The two halves split at the leading and trailing edge will ineviatble produce a weak wing .
look up google how to construct a lightweight yet capable wing structure.this is inevitably a rib /spar/stringer thing ...a possible compromise is D-box front section ... going from something like that you will be able to produce quality.I got the feeling it pays off to look more towards airframe construction than to look for what guys are publishing about their race car wings...

[prepel]

Thank You all for contributing, I do have ribs positioned in wing around nose mounting brackets and then half way along wing with 5mm cf end caps. I was hoping that the core density might provide additional strength around mounting brackets but i can see why this wont affect at all.
I have redesigned the attachment of the mounting units and such has increased the structure better. The wing doesnot bend as much as before. Thanks all. =D>

[marcush.]

feeding the forces into the wingstays is a crucial one to me.You will need to spread the loads and supply something to avoid crushing of the core material as well...so an insert is necessary .to increase stiffness along the spanwidth you could fit in some stringers that will be able to add some strength .

an of course you could connect all the wingribs using an internal tube going through those .If this tube is not constant in diameter /wall thickness you can even add stiffness along the span as you want need it...

[conni]

Core density will not really .. it`s more brittle it will just break the core I´d think.
The two halves split at the leading and trailing edge will ineviatble produce a weak wing .
look up google how to construct a lightweight yet capable wing structure.this is inevitably a rib /spar/stringer thing ...a possible compromise is D-box front section ... going from something like that you will be able to produce quality.I got the feeling it pays off to look more towards airframe construction than to look for what guys are publishing about their race car wings...

Rohacell is definately used and the parts arnt weak at the leading and trailing edge due to the construction method which is to trim the 1st ply to the edge of the mold on both top and bottom molds then on 1 half you leave all the others longer by 5mm on each ply and trim the other half back 5mm on each ply then wrap the rohacell in film bond put it in the long half and fold the extensions back over the rohacell then bolt the molds together and there is usually some loose tooling to go in the ends

conni

[marcush.]

I just cannot fathom the idea of how you would be able to do an oversize core and manage to get it inside the mold + all the plies...
When things are around like syntactic expandable core materials ...I´d guess you could do the main core to size ,put adhesive film and a sntactic core on top fit it all inside the mold and let the expanding core do the trick.I´m sure you need a very good and sturdy mold to get this working but for sure that would give uniform pressure to the laminate ..
http://www.ambercomposites.com/amspand-es72a-1

[polarboy]

It does work thou,core is to size or just over size and that along the expansion as it cooks is enough, the only thing you have to be aware of is not to nip plies as you join the mould
Amspan !!! brilliant stuff you should try to get a sample an just pop it in a oven at 125/c an see what it does,650% exspansion is fun to see