Carbon fibre moulding (chassis design update)

[FW 21]

Hi guys, im a newbie here and decided to weigh in on this topic.

I have been laminating F1 chassis for 7 years now and would be pleased to try to answer any questions you have as to how its done.

Kurtiejjj, you are taking a massive step to try this yourself and I wish you the best of luck!

As for the pics you posted of the mould you are interested in, I was wondering what car they were for.

With the Ferrari that split in half, you may be interested to know that the actual chassis split Ferrari use is in fact where it broke.

They laminate the rear and front sections complete and then bond the two halfs together. After this they laminate strips around the chassis.

Most other teams laminate a top and lower half and then bond or laminate these together.

Good luck with your project!

[Carlos]

Heres a series of pictures from a DIY - cut and fold honeycomb chassis construction project -

http://www.opencortex.org/nd00000055

I don't have anymore information on this project.

I am also interested - the mould - what was the marque's name and designation - Thanks in advance.

[kurtiejjj]

Hi guys, im a newbie here and decided to weigh in on this topic.

I have been laminating F1 chassis for 7 years now and would be pleased to try to answer any questions you have as to how its done.

Kurtiejjj, you are taking a massive step to try this yourself and I wish you the best of luck!

As for the pics you posted of the mould you are interested in, I was wondering what car they were for.

With the Ferrari that split in half, you may be interested to know that the actual chassis split Ferrari use is in fact where it broke.

They laminate the rear and front sections complete and then bond the two halfs together. After this they laminate strips around the chassis.

Most other teams laminate a top and lower half and then bond or laminate these together.

Good luck with your project!

Well that would be great to have someone to ask things when I would get stuck with this project. I'm still thinking what to do, what option is the best for me.

It would be great if you could tell me how much carbon I approximitally need for making a chassis, it of course doesn't have to be as strong as a proper F1 chassis as that would be ridiculously expensive. Would 5000 pounds be more than enough in terms of expense?

By the way how in thank heaven's name do you bond the bits together with glue obviously, but how do you make the top smooth and equal without carbon fibre strings coming out of the top?

By the way thanks for that page carlos I will look into it in more detail this afternoon.

[Carlos]

I've read a couple of books on building DIY light planes with carbon fiber - when there is a joint between 2 pieces - or joining a carbon fibre fabric seam - CF tape and resin is used - uneveness and stray fibres - thingies - are cut before curing - after curing a slurry of CF micro balloons and resin is spread over for smoothness - I may have posted the titles of the 2 books on airplane DIY before - I hope FW21 - can show us how it's done in our favourite field - F1

Welcome to the Forum FW21 - we have a number of professionals on the forum - although work contracts are restrictive - it's always great when pro-opinions can be offered - we understand that many specifics can't be discussed. Welcome to the Forum. Kurtiejjj's thread is one of the most widely read - along with the Developemental Car thread you may have noticed on the home page - advice on that thread would also be welcome. Good to have you both on the Forum - we have an exceptional group of enthusiasts at F1technical. Well Met.

[FW 21]

[Well that would be great to have someone to ask things when I would get stuck with this project. I'm still thinking what to do, what option is the best for me.

It would be great if you could tell me how much carbon I approximately need for making a chassis, it of course doesn't have to be as strong as a proper F1 chassis as that would be ridiculously expensive. Would 5000 pounds be more than enough in terms of expense?

By the way how in thank heaven's name do you bond the bits together with glue obviously, but how do you make the top smooth and equal without carbon fibre strings coming out of the top?

By the way thanks for that page carlos I will look into it in more detail this afternoon.[/quote]

First you need to know what you want to use the car for, as for costs,it depends on what quality of carbon you use and of course how much.

Do you require good side intrusion? if so how good?

What kind of torsional stiffness do you require?

As for your mould, you need to ask what temperatures it has been cured at in the past and what pressure it was used at.

Ask also for the seatback bulkhead mould, this could save you a lot of hassle later on.

Does the mould include the rear and front faces?

As for making the top edge flat, if I understand exactly what you mean, its very simple.

After you know what the thickness of the chassis will be (including what thickness honeycomb you want to use) you can bolt a plate (aluminium will be fine) with the thickness offset over the split line to create a nice flat edge after the part is cured.

Simply laminate and trim the plies to the top of the mould (upper and lower half) and then bolt on the plate before curing.

I am assuming that you will use pre preg carbon?

Without this plate, after curing you will find that the split edge has rounded off due to the vacuum bag. This creates not such a good bonding surface for when you want to put the two halves together.

The glue most commonly used is 3M 9323, I cant remember its full name, I'll get it for you. Its bloody strong and all of the parts glued in and around the chassis are done so with this glue. I recommend you use this for all chassis bonding!!!

Hope this is a start, Im always around if you have more questions.

[kurtiejjj]

hmm, that cleared the bonding process up for the moment I have done a bit of calculating some time ago but I doubt it they're right, I will have to recalculate, damn maths.

[FW 21]

hmm, that cleared the bonding process up for the moment I have done a bit of calculating some time ago but I doubt it they're right, I will have to recalculate, damn maths.

With the bonding, dont forget you cant just stick the two halves together!

I would advise a joggle or maybe a tounge and groove joint.

Also it is possible to laminate the two halves together after you have finished the top and bottom.

[kurtiejjj]

Hmm, let's see still nagging me so much what to do, I quite like the idea of buying an old race car and drive it from time to time. But building something myself would be a really interesting challenge perhaps other people would even be interested in buying one (oops too optimistic).

OK with the bonding process soedn't seem to be a very big problem.

As for the design of an LMP car I was thinking that it might be interesting to build a bottom half mould which will always be the same and build a top half that can be a closed or open sports car version. If I were to build more that it is .

I was still thinking about the engine, it will have to be in a subframe as it is a motorbike engine but I'm not sure about the stifness of these things. maybe it would be a better bet to buy a ford duratec or some BMW engine and upgrade it with parts available from specialist.

What do you think?

[Carlos]

Well - You have found some very good prices on race cars - buy one that is simple and inexpensive to maintain - and enjoy it. Then set to a long term project of designing and building a chassis yourself. You would have an enjoyable track car now that would give you the experience to design a car later - and have a great time doing both

[RH1300S]

I would veer towards a bike engine for a project of this type. You will get more bhp per unit of weight than with a car engine. Surely if you start with a lighter engine it's easier to make everthing else light. A crude argument - but roughly along the lines of......heavy engine needs a stronger chassis, which would need bigger brakes, bigger tyres, bigger hubs - the list goes on. Conversely..........start with a small light engine and keep adding lightness

Some bike engines do some work as a partially stressed component, but I supsect that a small neat space-frame would be the smart way to mount the motor and rear assembly.

[BreezyRacer]

I would veer towards a bike engine for a project of this type. You will get more bhp per unit of weight than with a car engine.

Just make sure to dry sump it. Those bike motors were not designed to stay flat under cornering loads.

[rizo]

nothing to do with the subject but I want to thank you all for this forum.
I am an engineering student and can say this is not only helping kurtiejjj.
thanks

[kurtiejjj]

@ Carlos, yes indeed I could do both simultaneosly, designing something isn't going to cost anything other than time, paper and a pencil. I know a few interesting things around but it won't be an F1 car after all. Too much fuss and costs too much after all, it's the buying price that lures people into the turbo f1 cars. However a hart turbo is pratically the same as the F2 harts. I will go the old F2 way I think a lot more simple in every respect, mechanical, driving etc. and best of all cheaper and that's what I like!

I'm an avid fan of lightness (I just have to look at myself too confirm that ) and so it would be obvious too choose a bike engine. But the only series here in europe in which you would have a chance is the 750MC but they don't accept carbon thingies. So I would have to go interseries that kind of thing but there is no way you will make a chance against these bmw 6 pots driving around there, they will have so much more top speed that they will have overtaken you at the end of the straight after you shot past them in the corners.

[Carlos]

Is Hillclimb still a popular motorsport? I remember years ago it was very important - and there was a class for just about every car that showed up - all sorts of prototypes and engine sizes - large manufacturers like Porsche and many small builders like Abarth. Every kind of Formula car F1/2/3/Ford participated. Perhaps they would accept a motorcycle engined racecar with a CF monocoque. Purchase something now to race, learn from and enjoy - your experience in the pits - looking at all the other machinery would also be useful.

[Tom]

No, it seems to have dies, shame because I wanted a go, but there's nowhere that does it anymore, there used to be several events up here but they've all gone.