hootsno1
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posted on 19/1/11 at 08:50 PM |
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can they be made out off billet ally???
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ettore bugatti
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posted on 19/1/11 at 09:12 PM |
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IRCC fatique was attention point when engineering and constructing in billet ally. You could use airspec 6061 alloy for the uprights.
Formula Students have extensive analysis on their suspension and their reports are widely avaible on the web. Those crazy students aren't afraid
to engineer in exotic materials
You could use filament carbon tubes, you then only have to figure a clever joining system
PS: Why is this in the bodywork section?
[Edited on 19/1/11 by ettore bugatti]
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ettore bugatti
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posted on 23/1/11 at 04:34 PM |
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Informational link:
http://fsae.com/eve/forums/a/tpc/f/125607348/m/15110476641/p/1
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Benonymous
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posted on 25/1/11 at 12:42 AM |
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Reminds me of an aluminium chassis thread
This thread reminds me of the many "why not build the chassis out of aluminium" threads.
If you want to save weight on a clubman style car there are many, many ways to do it without resorting to experimental parts in critical areas of the
vehicle. The running gear is one area that I would never attempt to use exotic untested materials in.
Sure, F1 teams use CF for everything but an F1 car is unlikely to have a wheel drop into a pothole on a B road or clip a concrete kerb. I know F1
cars run over ripple strips on tracks and so forth but they are not putting massive instantaneous loads on the suspension when they do. I read an
article once that pointed out "Carbon fibre has a very high strength to weight ratio but when it fails, it snaps like a carrot!"
That's your wishbone he's talking about.
Metals tend to fail more progressively and so you'll avoid that look of a crashing F1 car with the wheels flying off in four different
directions.
You'll never regret over engineering the running gear on your car but you'd definitely regret under engineering it.
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coyoteboy
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posted on 26/1/11 at 01:09 AM |
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"PS there is a reason why only cross-country, and road bikes, have gone the CF route for main tubes. Downhill bikes would shatter like glass and
stab the rider senseless in the event of the inevitable failure. Things break regularly on DH bikes due to the forces. I don't miss the falls
one single bit, and I certainly don't miss the A and E wards I saw with regularity."
I've a 6" travel single-piv frame with a carbon swingarm, still going strong after nearly a decade of use
But I wouldn't use carbon on the wishbones for the two reasons I see noted above. 1 - when they fail they fail spectacularly - there'd be
no pullin to the side of the road with a screech - it'd be snap, scrap, stop at best. 2 - the weight saving is minimal for the effort and
concern I'd have over the final result. And I'm one of those crazy student types making stuff in exotic materials. We've billet
uprights, carbon driveshafts, custom-housed minimalist diff, but our arms are still good old steel tubing ![](/images//smilies/smile.gif)
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hughpinder
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posted on 26/1/11 at 10:10 AM |
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If its for a track only car then I'd say go for it!.
If its for a road car, I'd say save the sprung weight elsewhere - 13" wheels, thinnest/lightest brake disks etc
Regards
Hugh
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Neville Jones
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posted on 27/1/11 at 11:19 AM |
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quote: Originally posted by hughpinder
I'd say save the sprung weight elsewhere - 13" wheels, thinnest/lightest brake disks etc
I like how folks have now cottoned on that those big wheels and rubber band tyres are heavy.
Not so long ago the slightest suggestion of binning those big bling wheels would have been met with shouts of derision, as happened when a close
acquaintance of mine made the very same suggestion.
Cheers,
Nev.
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Triton
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posted on 27/1/11 at 03:30 PM |
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I would say using carbo fibre for wishbones to save a knats knacker in weight wouldn't be worth the expense, if they were stroner enough for
road use in the first place!!!
Fit a bike engine, 13" wheels and don't eat so many pies...........
My Daughter has taken over production of the damn fine Triton race seats and her contact email is emmatrs@live.co.uk.
www.tritonraceseats.com
www.hairyhedgehog.com
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britishtrident
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posted on 27/1/11 at 04:51 PM |
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Think about this military combat helmets are made of Kevlar (they likely also contain glass fibres in the lamina) not carbon fibre.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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interestedparty
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posted on 27/1/11 at 05:47 PM |
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quote: Originally posted by hootsno1
can they be made out off billet ally???
That is how RCR (race car replicas), a big kit car firm in Detroit, do them, IIRC
As some day it may happen that a victim must be found,
I've got a little list-- I've got a little list
Of society offenders who might well be underground,
And who never would be missed-- who never would be missed!
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Badger_McLetcher
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posted on 27/1/11 at 08:36 PM |
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Just to add another voice to this- No. Just no.
If disfunction is a function, then I must be some kind of genius.
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MikeR
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posted on 27/1/11 at 08:55 PM |
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Can i go back and resuggest wrapping steel wishbones with fake carbon. It will add a couple of grams and will look the business (if thats your sort of
thing) until it gets chipped.
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B120WNY
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posted on 27/1/11 at 09:04 PM |
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What about making the wishbones out of T45 alloy?
They'll be substantially lighter than the steel ones, then you always have the option of wrapping in carbon fibre film to give them the look,
they'll be light and look nice, but won't be as expensive or risky as the pukka carbon ones.
[Edited on 27/1/11 by B120WNY]
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greggors84
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posted on 27/1/11 at 09:45 PM |
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At the start of last season HRT were running steel wishbones with carbon shrouds. If its good enough for F1....
Chris
The Magnificent 7!
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shaft
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posted on 27/1/11 at 10:15 PM |
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We make carbon wishbones at work for 2 top F1 teams.
£25k for a set of 4 anybody? please bear in mind that doesn't include
the titanium end fittings for mounting or the bespoke match fitted rose joints
for adjusting them, but does include X-rays of each component and full traceability
of all materials used.
They are, however, 10x stronger than any alloy steel ones , but as mentioned
earlier by others, only in the direction they are designed to work.
You go over a kerb at a race track or a pot hole on the road, they won't even blink...
Nudge one forward or backward though and they'll snap like a carrot.
Joking aside, there's hardly any woven fabric in them. It's 90% UD (uni-directional)
material and hoop plies which are basically horse sshoe shaped hoops of UD
which go around each end and then fan out up each leg internallyy to load spread any pull
up the entire leg.
They are moulded in halves, 3D profile CNC machined, then bonded together in a bespoke
fixture in an Autoclave.
Woven is mainly used as edge trim to prevent spelching whilst machining them.
HTH
Nick.
EDIT: Forgot to say... the "Flexure" area of each leg is only 4.8mm thick!!!
[Edited on 27/1/11 by shaft]
my opinion might be wrong you know...
My Zero Build Pics
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