Carbon Fibre Composites - rookie

[Klemmel]

I’m taking a mandatory course where we are five students with different backgrounds that are supposed to solve a problem (the point is that we are going to work as a team).

Our task is to design and build a new seat for the university’s Shell Eco-Marathon car (Shell Eco-marathon - Shell Eco-marathon). The seat has to weigh less than 450 gram and we are going to use carbon fibre. The problem is that none of us have any skills in this field.

My task for now is to find out as much as possible about this material and how to use it. I know there is always google and youtube, but do you guys have any web-sites to recommend or do you personally know much about this material? If so, let me know below!

[johnnynumfiv]

I've seen a build about a guy making all the body panels for his mustang in carbon fiber but that was years ago and searching hasn't come up with anything.
This seems like a pretty active forum on cf, Werksberg Composites Forum - Powered by vBulletin
Motorcycle Parts From Carbon Fiber - webBikeWorld
Composite Panels Classroom-- Car Craft Magazine

[P4g4nite]

450gm? i suggest you use this:
Just plopped it the car floor, tell them it came in at under half the weight and twice the comfort!

[RacingManiac]

Fiberglass & Composite Materials: Forbes Aird: ISBN 9781557882394

Most composite material can be made in the same way, although specific material properties depends on what you are using and how you are using it....this book is a good primer...

[Zorlox]

If you want the bible of composites, get the ASM Handbook Volume 21 Amazon.com: ASM Handbook Composites Volume 21: Steven L. Donaldson, Daniel B. Miracle: Books

Otherwise another good book is Amazon.com: Fiberglass & Composite Materials: Forbes Aird: Books

"do you personally know much about this material"
-yes, I'm studying composite materials engineering. we're making a gravity racer out of carbon pre-preg right now.

You'll most likely have to decide between hand layup, VARTM, or using pre-preg.
Hand layup is the easiest and cheapest generally but the parts aren't the best quality. VARTM and pre-preg are both very clean methods and I'd recommend using one of those.

The idea is carbon fibers are saturated in resin (epoxy, polyester, etc) and then allowed to cure making a stiff part. The carbon fibers usually make up 50% of the weight of the finished part. Pre-preg is a little different; the fibers are already saturated but the part won't cure until heat is applied.

[Auxin]

I honestly think you should just go with cushion guy's idea.

[Knuto]

Originally Posted by Zorlox

If you want the bible of composites, get the ASM Handbook Volume 21 Amazon.com: ASM Handbook Composites Volume 21: Steven L. Donaldson, Daniel B. Miracle: Books

I was about to name that one. I also heard Mil-17F is one 'bible'. Check it out here

[Klemmel]

Originally Posted by Zorlox

"do you personally know much about this material"
-yes, I'm studying composite materials engineering. we're making a gravity racer out of carbon pre-preg right now.

You'll most likely have to decide between hand layup, VARTM, or using pre-preg.
Hand layup is the easiest and cheapest generally but the parts aren't the best quality. VARTM and pre-preg are both very clean methods and I'd recommend using one of those.

The idea is carbon fibers are saturated in resin (epoxy, polyester, etc) and then allowed to cure making a stiff part. The carbon fibers usually make up 50% of the weight of the finished part. Pre-preg is a little different; the fibers are already saturated but the part won't cure until heat is applied.

Do you know if it is difficult to combine metal and CF?

[Zorlox]

It shouldn't be too difficult as long as the metal surface is prepped (no grease/oil, sanded with ~220 grit sandpaper). You do have to be careful if you're using an oven to cure or post-cure the part since cf shrinks as it's heated and the metal will expand. It's also common to use glass fibers for the surface directly contacting the metal.

[Klemmel]

That's helpfull... Thanks!

[Dino Scuderia]

You should see the composite plywood car you can get at Ikea.

[Bob]

Originally Posted by Klemmel

Do you know if it is difficult to combine metal and CF?

I do... do it every day. My shop contains both our own Shell Eco Marathon car, and our Formula SAE car... the Eco car is much simpler/less work than ours.

We do all our bodywork from CF, using wet layup since we don't have the facilities to bake a while car. CF requires a lot of time, a lot of sanding, and a lot of prep. but combining it with metals actually isn't that difficult... just yesterday i made the magnesium threads that will connect our cf air filter to cf intake.

[pjmanktelow]

I think you'll be overcomplicating things if you try to use Carbon Fibre, only in saloon style cars, (Touring, Rally etc..) do seats have ridgid composite frames. All openwheel racers (including F1) use simple bag seats. Take a bin bag, the lighter the better, place it in the car put in an amount of two part expanding foam and have your driver sit in. The foam expands to fit around the driver and the space in the cockpit. The ones in our formula fords weigh around 210 grams.

Remember the following:

The lighter the better,
The simpler the better,
It's not a limousine, comfort is a luxary you can't afford.

***Don't buy the "Seat Foams" on ebay they'll rob you blind***

***The local fibreglass supllier will sell 10 times as much for 1/2 the price***


Good luck.

[RacingManiac]

It might be more of a space issue with the foam inside the small eco-racer. Thin foam seats collapse pretty easily and you might need to glass over the foam seat to retain the integrity. Our FSAE car also uses foam seat.....I do think there was little need for carbon fibre for the seat purpose. If anything regular fibre glass shell probably will do the trick, and be a lot cheaper....

[Juggs]

Originally Posted by johnnynumfiv

I've seen a build about a guy making all the body panels for his mustang in carbon fiber but that was years ago and searching hasn't come up with anything.
This seems like a pretty active forum on cf, Werksberg Composites Forum - Powered by vBulletin
Motorcycle Parts From Carbon Fiber - webBikeWorld
Composite Panels Classroom-- Car Craft Magazine

heres the link your looking for. The cars really coming together. He does talk about the process of working with carbon fiber a lot in there too. check it out.
Sub 2500 lbs. 96 Mustang Cobra Project... - Corral Forums