View Full Version : How strong is carbon?
For example, could I make a copy of innerwings and bolt the stutt into it?
Would a carbon chassis legs be ok on the front?
if you made straight copies, i can't imagine they would be structurally as strong as the steel ones, but designed properly, using the correct materials, they would be way stronger.
I was thinking that copying the standard part using a carbon/Kevlar material layered several times may have been strong enough?
Obviously the chassis legs would need to be done in 3 parts and bonded together
but how would you mount them to the rest of the car? thats where the problems will be
david dixon
27-01-13, 10:08 AM
It depends how thick and how well its put together....i could stand on the older carbon bonnets and they wouldn't move!
Well this is where the story goes a bit silly lol
I had a few drinks last night, I had spent most of the day moving my parts around for better storage
I have 70% of a nova in new panels, I've had silly ideas in the past, can you see where this is going lol
Now a few things, Yes I know it's Fcuking expensive for the materials yes I know making moulds is a PITA but I'm thinking? Can it be done?
Bonding cars together with glue isn't a new thing, BMW have been doing it for ages now and more cars are repaired by glueing panels rather than welding so the method and materials are easier to aquire nowadays
It depends how thick and how well its put together....i could stand on the older carbon bonnets and they wouldn't move!
I was thinking about resin infusion as my best way forward :)
I'd not want a like for like design of a steel part made in carbon/composite for something structural....
Steel and composite are very very different.... A structural pressing in steel will be better suited to the task than a direct copy in composite.
Even the carbo-titanium kit car I work on has steel front and rear frames to deal with the structurally vital bits.
Hmm you've confirmed my fears lol
What I had previously thought about was an alloy front frame and rear suspension frame and the rest in composite
So maybe an alloy space frame with a nova shell would be the best I could do :(
Your Lottery numbers come in?
can't you do a west coast customs type job & fit the top of a nova onto the bottom of something else???
it was also done with a viva on eBay that appreared to be a mk3 astra convertible underneath, with an escort cabrio hood cos it looked better, then it was sold on its original reg......
Based on what I was taught at uni, steel for a tubular chassis is the best route unless you have big money and a totally blank canvass.
I wish lol
Just be a shame to pass up the chance of taking moulds from the parts before they get used,
Like most of my ideas it'll probably come to nothing but worth looking into I guess
this is spaceframe & carbon...
http://i239.photobucket.com/albums/ff259/Razzer-photos/mk1043.jpg
can't you do a west coast customs type job & fit the top of a nova onto the bottom of something else???
it was also done with a viva on eBay that appreared to be a mk3 astra convertible underneath, with an escort cabrio hood cos it looked better, then it was sold on its original reg......
I had thought about that with a 8L S3 Audi as they are bloody cheap now but it would still weigh far to much,
Just shorten the wheelbase and widen the nova a bit,
The idea of a light nova was for some trackday fun, just the difference going from a 1400kg Audi to the gsi nova at around 800kg was bloody surprising so I thought " how light could one be made ? "
i was thinking more on the lines of a corsa b... lol but why not stick something meaty in
I've not really thought that far ahead lol
That escort is pretty damn nice !
steviegsi
27-01-13, 11:28 AM
from the parts before they get used,
lol
A bloke I work with has made a complete fibreglass anglia
What's it built on burgo? The original floor pan or space frame?
I think hes just got a ladder chassis running down it being as theres a v8 bolted in as well
Nice, seen one years ago running a YB, still think they look pretty cool.
Iirc the lotus esprite used a dovetail chassis and fiberglass body?
16xe_chris
27-01-13, 12:27 PM
Carbon fibre can be potentially very strong.
If you were making something very structural it would have to be done in an auto clave using pre-preg carbon as this will make the strongest part possible.
Infusing it will make it strong but not to the levels of supporting chassis legs etc
You could keep or make a space framed alloy version and simply make the rest of the shell out of carbon fibre.
Novasport
27-01-13, 12:29 PM
I wish lol
Just be a shame to pass up the chance of taking moulds from the parts before they get used
Well you have about 20 years then to copy them. If you run out of time you will have an extra 20 -30 years to use mine ;)
Nice, seen one years ago running a YB, still think they look pretty cool.
Iirc the lotus esprite used a dovetail chassis and fiberglass body?
knowing lotus, it used a modified version of the old backbone chassis that the elan used.....
Thanks Chris,
I think pre-preg is out of my league to be honest, alloy chassis may be the way forward if I get round to this,
I'm pretty sure I'll be making moulds of the parts now though, storage isn't a problem as I have plenty of space and time isn't really an issue either at the moment,
Out of interest would anyone know how much a pre-preg chassis leg would cost to be made?
you'd probably get change out of £50k
Hmm kinda a bit more than I'd like to spend lol,
16xe_chris
27-01-13, 12:46 PM
you'd probably get change out of £50k
This tbh
I could tell you how to do it a bit cheaper but then I'd have to shoot you lol
mike is the one to ask as his labour rates are crazy cheap.
what about going to a few kit car shows with a tape measure?? someone might have a good chassis that would fit.. but it might make the car rwd......
16xe_chris
27-01-13, 12:50 PM
mike is the one to ask as his labour rates are crazy cheap.
what about going to a few kit car shows with a tape measure?? someone might have a good chassis that would fit.. but it might make the car rwd......
Mike doesn't have an auto clave yet
And buying one big enough to to a chassis leg is mega bucks lol
Ooft, they things ain't cheap lol,
I stopped looking after I noticed the prices at 50k for a 700litre one lol
Some of them are bloody huge though, the size of an artic tanker !! They must cost a pretty penny !
16xe_chris
27-01-13, 01:54 PM
There not cheap matey, got to have plenty of parts going through them to get your money back lol
/\ precisely, once the moulds are sorted, the copies are way cheaper to make..
for a nova chassis, you'd probably manage to sell 20 units globally, more if it comes wide-arched or ready to take big block mechanicals,
BRoadGhost
27-01-13, 03:06 PM
Threads like this are pure nonsense.
Really?
Why?
I would'nt mind your insight Mr ghost, your opinion, anything other than your usual negative comments, perhaps even a suggestion on a way forward?
I've planned to copy my full quarter panels in composite for sometime and im still learning about the process.
I always thought that we learn by asking questions and aspiring to do the best we possibly can. If I end up wasting 3 grand on materials then so be it at least I am willing to try.
How much are full car size claves?
bazzap8389
27-01-13, 05:25 PM
Is an autoclave just a big oven really? If so we have one at work you would easy fit a car in.
Bit more complex than just an oven. Need to be able to hold precise temperatures and pressures for given times etc
bazzap8389
27-01-13, 05:33 PM
I don't know about pressure but it defs keeps precise temperature. It's used for stress releaving welded jobs etc
stress relieving of welds sounds too hot for this..
carbon fibre curing is all about controlled pressure & temp, but the temp is relatively low, like 125degC
Jon_nova1
27-01-13, 09:23 PM
I personally wouldn't do what your proposing, there must be a reason why it hasn't been done, have you done any research into how shock/vibration/engine harmonics would interact with the weight load and cause any shattering of the chassis leg?
I wouldn't like to be doing flat out on a track to find my chassis leg shattering, the closest i've heard is CF driveshafts/propshafts designed to deal with the torque
Hence why a thread asking for advice, this thread is part of my research
Re price....
How much in a monetary value would you put on your life.
And that is your answer.
When it comes to strength though, the operater can make it as strong or as brittle as is required. I make parts at work that can take over 5 tonne weight before collapse, using an aluminium honeycombe core. But these are multi million pound defense/aero projects.
And, TBH you would severly struggle to find anyone mad enough to put there rep/life/product liability insurance on the line aswell.
As for autoclave, they start at about £30k for a used, fair specced auto working clave. Another £10k ish for the cooling setup, installation costs of around £4~8k. Thats exlucing tonnes of other costs like delivery on a HGV, fork lift truck hire to move it etc etc The cheapest clave I use at work cost just under £200k, the dearest was nearly £550k.
Anyway, once the above has been hypothectically overcame, it still leaves a lot of other headaches like tensile strength rating v's matierial choice, matierial Tg, pattern manufacture, pre cure setup, post cure setup blah blah blah.
Well that's my structural questions answered lol
Well that's my structural questions answered lol
The more money invested, the better % itll potentially work. But building a composite crash structure is risky business :/
Mclaren tried it, didnt suceed. Noble didnt even bother, neither did Audi. Space frame chassis is by far the safest.
Dont get me wrong, its an awesome idea, but seriously dicy.
Cheers mike, thanks for your opinion.
One last question, how do carbon or Kevlar panels react to fire?
As imagine a spaceframed design using all composite panels including bulkhead?
One last question, how do carbon or Kevlar panels react to fire?
Depending on the peak temperature generated, it'll be somewhere between very bad to castostrophic lol
If the molten liquid epoxy doesnt strip your skin off first, the smoke will 110% garantee kill you without a doubt. BUT, if you somehow manage to survive that, the dust generated from cleaning it up/putting fire out would probably kill you more dead lol
Think I'll now give up on this idea lol
The more money invested, the better % itll potentially work. But building a composite crash structure is risky business :/
Mclaren tried it, didnt suceed. Noble didnt even bother, neither did Audi. Space frame chassis is by far the safest.
Dont get me wrong, its an awesome idea, but seriously dicy.
i thought mclaren used ally honeycomb crumple zones on the f1gtr, cos according to the local legend at mira, they crash tested the prototype, then bolted a new nose cone on & drove it back to woking.
Bizarrely after saying about the fibreglass anglia I got to work today and he had brought it in
http://i12.photobucket.com/albums/a226/sclurgess/20130128_072837.jpg
BRoadGhost
28-01-13, 11:14 PM
It's pure nonsense because almost anything be made strong enough if bonded on correctly. How thick, what shape, what size..?
Just as a case and point, people 'that know' can make fully functioning firearms [live ammunition] from paper.
...May as well ask people how long is too long when cutting string. I'm saying more or less saying that if you've gotta ask, then you don't know. Heh I'm in old grumpy mood today :)
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