phil_far
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 posted on 26/5/04 at 04:20 PM |
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CFRC Panelling
Has anyone tried panelling a locost (or similar) chassis in CFRC (Carbon Fibre) sheet insted of Aluminum? If yes what thickness was used and how was
it attached (riveting?). From wher was it purchased and at what price?
Philip
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spunky
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| posted on 26/5/04 at 04:34 PM |
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quote:
Originally posted by phil_far
Has anyone tried panelling a locost (or similar) chassis in CFRC (Carbon Fibre) sheet insted of Aluminum? If yes what thickness was used and how was
it attached (riveting?). From wher was it purchased and at what price?
I can answer one of your questions.....
EXPENSIVE
John
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zilspeed
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| posted on 26/5/04 at 04:39 PM |
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Here you go - half way down the page is a carbon bodied westfield
Fluke Motorsport carbon bodied westfield
Big bad monster expensive spec on everything.
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nicklondon
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| posted on 26/5/04 at 04:55 PM |
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the same car is in this months track and race car mag.
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britishtrident
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| posted on 26/5/04 at 05:53 PM |
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wow it must be at least 1kg lighter
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Terrapin_racing
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| posted on 26/5/04 at 11:52 PM |
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Try BRP Composites, Neale is very helpful & the prices will (pleasantly) surprise you.
I had a few square metres some time back
BRP Composites
Fox Barn
Pepperharrow Park
Godalming
GU8 6BQ
01483 861212
info@brpcomposites.co.uk
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crbrlfrost
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| posted on 27/5/04 at 01:59 AM |
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I don't see any real advantages to using carbon in the place of aluminium for the application. If lightness os the concern, then I'd
suggest carefully selecting where to go thinner, or perhaps sandwich type panels. Thin carbon panels are not going to be much, if any stiffer then
aluminium, more prone to cracking and there is always the issue (arguable, but well supported both ways) of the corrosive nature of carbon-steel
junctions. Frankly I think you'd be better off molding the cowl, bonet and nose in carbon, as those are easier to do, non structural and higher
on the chassis than the shear panels. But thats just my two cents. Cheers!
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F1 Mini
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| posted on 27/5/04 at 08:16 AM |
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If those carbon panels where glued onto the chassis with the correct glue, then that would make the chassis alot more rigid. Ally is very soft in
every direction, carbon isn't.
There's one advantage anyway,,, oh yes and it looks as SEXY as hell.... Thats 2
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JB
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| posted on 27/5/04 at 08:15 PM |
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Carbon v Ally
I am not sure what grade of aluminium you all use but I would suggest that a high grade such as 5251-H22 (NS4) would be easier, cheaper and probably
lighter and stonger than carbon.
Aluminium sheet has come down in price recently I pay around £15 for a 2000mm x 1000mm x 1mm sheet from Baco Metal Centres.
Use proper rivets (not soft aluminium) and bond to the chassis and it will be very strong.
I have done carbon panels. You require at least 2 layers of carbon at around £15 per metre square, plus gel coat and resin. Also it is messy and
smelly.
Leave the carbon for curved panels.
John
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crbrlfrost
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| posted on 27/5/04 at 10:13 PM |
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Lets see....Carbon is extremely soft in most directions that do not lie along its axis. That means its anisotropic and difficult to model, especially
for backyard use. Carbon isn't great in conpression, thats another thought. There are reasons that in structural cases its used in sandwiches,
unidirectional reinforcement and cables. In non-structural applications you can use it however you want. Personally, I think a mild alloy like 6061
would be rather well suited (relatively high strength <as good as mild steel and then some>, easy forming in "O" state, good
machining and weldability). Oh, and it is much closer to steel in the galvanic reaction tables then carbon, which means you won't have to
rebuild the chassis every few years (unless you made the chassis out of Titanium, which is pretty close to carbon). But, ya builds your chassis, ya
takes your chances. Cheers!
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crbrlfrost
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| posted on 27/5/04 at 10:17 PM |
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PS, I strongly agree with JB on the use of proper rivets (cherry Q, not N, or equivilant would be a good place to start) and bonding with a good metal
to metal agent. Quick note, even with bondingm even if confident in its strength alone, always rivet the corners, as bonding is not so great in peel
as it is in shear. And peel always starts at the corners. Cheers!
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Hugh Paterson
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| posted on 28/5/04 at 12:07 PM |
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You tell em Syd I'll buy that fer a doller
Shug.
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crbrlfrost
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| posted on 28/5/04 at 05:20 PM |
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I maintain what I have already said. But frankly I don't feel the need to argue it further. I've done the analysis, I've done
experiments. But out of curiosity, how thick are you making your lay-ups (5.7oz cloth about 7thou) and what bonding agents are you planning? And since
you want to lay it up -45/45, you get better interlaminar strength with uni running 90deg to each other than two like fabrics on top of one another.
Of course a symetrical layup about the center layer would be a good idea. I happen to work with composites as well, and have immense respect for them.
I don't think they are the perfect material for this application though. Happy building!
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flak monkey
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| posted on 28/5/04 at 06:41 PM |
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Syd i just think he was a bit miffed that you were accusing of being an 'armchair expert' when infact he too works with composites so is
probably just as clued up as you when it comes to these matters. And to be honest i think he desrves a bit of an apology....
I dont know anything about composites but, i have seen sevens done with carbon bodywork. How good it is i dont know. I think it would only save
minimal weight (yes i have done the weight calcs too!) And IMO not really practical for home locosting. If you (apparently) have the skills, great,
use them. If not then stick with ali....
Cheers,
David
Sera
http://www.motosera.com
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flak monkey
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| posted on 28/5/04 at 08:05 PM |
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Maybe he is just asking your opinion on what layup to use. And looks to me the was suggesting +/-45deg. (It makes sense to me too).
Maybe we are reading it different ways, i dunno.
Sera
http://www.motosera.com
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stephen_gusterson
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| posted on 28/5/04 at 09:13 PM |
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I must admit, the statement 'layup from corner to corner' did read to me like diagonal.
I've used alu, so I dont give a crap either way 
atb
steve
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Aloupol
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| posted on 28/5/04 at 10:02 PM |
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quote:
Originally posted by F1 Mini
If those carbon panels where glued onto the chassis with the correct glue, then that would make the chassis alot more rigid. Ally is very soft in
every direction, carbon isn't.
I'm not that sure. The stiffness function of the panels is fullfilled as soon as they exist (eh..) and they are rigidly connected to the tubes.
The stiffness of the panels themselves is not that important. But it's true that connection of carbon panels is better with glue (the right one:
I just remember it's called "Epibond" I will search for the exact grade) than with rivets.
Carbon+Epoxy is hard to drill (not hard to drill but bloody hard to correctly drill), is sensible to holes (crack starting) and doesn't react
well to the smashing force of the rivets.
quote:
Originally posted by F1 Mini
There's one advantage anyway,,, oh yes and it looks as SEXY as hell.... Thats 2
Yes that's true, it's the only and the good reason. Why should we search for a technical advantage? Is Kylie Minogue technically better
than Ms Thatcher? Does she run faster?
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flak monkey
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| posted on 28/5/04 at 10:50 PM |
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Kylie is better than Maggie in every way. Kylie could have probably even run the country better than her!
Cheers,
david
Sera
http://www.motosera.com
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crbrlfrost
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| posted on 29/5/04 at 12:01 AM |
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I read exactly what you said Syd, and for the most part did agree with you, except in it being an ideal application. That was a question I asked
however, simply implying that I'm resigning myself to the fact that people will use carbon and asking what your proposed fabric cloth weights,
resins and bonding agents were. I figured if I knew that, I might be able to at least better understand your position or discuss on that basis rather
than carrying on a pissing contest. But whatever, cheers!
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Hugh Paterson
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| posted on 29/5/04 at 09:47 AM |
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Carbon composite panels are not everyones cup of tea, indeed if they are subjected to overloading beyond their design limits, as has happened in the
aero industry (747 tailplane delaminated in yaw), and an Infamous trimaran that fell apart a couple of years ago. When it fails its dramatic and you
dont get much warning. In both cases the design had been subjected to computor modelling that failed to recognise loads in extreme emergencies and in
the case of the boat, failed to take into account the loads the hull was subjected to when the front and rear of the hull was hanging on the peak of
two waves, and the midships section had a hole under it  All dodgy events. Personally for the oggle factor, jaws dropping. (have a look at the body
on a Palmer car) it looks  and just to prove I "somtimes" play with this stuff there might be a wee bit of it on my car
eventually. For cost and speed of completion Ill be sticking to side panels in ali. Cheap and fast, just like my taste in women
Shug.
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crbrlfrost
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| posted on 29/5/04 at 03:57 PM |
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Hugh, that synopsis was almost poetic. Rights reserved I suppose Cheers!
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F1 Mini
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| posted on 31/5/04 at 08:13 AM |
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Oops sorry lads didn't mean to kick the honets nest etc. As may have said ally is alot easyer to work with and still very effective. I have
just sold my Ultima and it looked lovly inside with all that polished ally.
I just thought CF would be stronger, but I'm no expert as I havn't done any thing with it yet.
PS I do have Kylies Calender though......Lovly figre.......
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Hugh Paterson
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| posted on 31/5/04 at 02:21 PM |
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So let me get this right u sold an ultima
to do somthing with a Mini, and I thought I wuz nuts
Shug.
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F1 Mini
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| posted on 31/5/04 at 11:26 PM |
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Yes but You don't know about this yet do you ...... and yes its Kevlar and carbon.....
[Edited on 31/5/04 by F1 Mini]
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F1 Mini
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| posted on 31/5/04 at 11:30 PM |
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And there's this little brute that's sat in my garage ready to go in it. 649bhp on a British dyno, 606Lbs...
 
Rescued attachment DSCF0018.JPG
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