purdy
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| posted on 3/8/08 at 09:10 AM |
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Alloy chassis
Alif27 and i are contemplating a bec and making an all alloy chassis ali wish bones and with Grp body Coverings for a very light car ...trackdays
only.
Anybody Know of anyone that has done this previously for the crack?
Purdy
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speedyxjs
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| posted on 3/8/08 at 09:12 AM |
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Do a search. Alloy chassis has been discussed ALOT
How long can i resist the temptation to drop a V8 in?
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eznfrank
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| posted on 3/8/08 at 09:13 AM |
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I don't think anyone on here has ever done it (or not that they'd admit to anyway  ).
It has been mooted a few times on here but I think the conclusion is usually that it would be about as strong and durable as a chassis made from
cheese.
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Richard Quinn
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| posted on 3/8/08 at 09:14 AM |
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Discussed many times that I'm aware of. Spooky that you have the words "alloy", "chassis" and "crack" in the
same post.
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tegwin
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| posted on 3/8/08 at 09:14 AM |
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This has been discussed a LOT over the years....
The general consensus is that without a lot of very expensive and complex processes you will end up with a chassis that is dangerously weak....
Space frame chassis (Haynes roadster) are best made out of steel....
If you want an ali chassis you need to look at monocoque...and perhaps gluing it rather than welding to avoid some of the heat issues assosicated with
welding...
A well desigined and built mild steel chassis would easily be lighter than an ali chassis unless you really really know what you are doing...
------------------------------------------------------------------------------------------------------------------------
Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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purdy
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| posted on 3/8/08 at 09:16 AM |
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MMMMMMMMMMMMM Cheese
Vorstsprung Durch Purdys Technic
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purdy
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| posted on 3/8/08 at 09:19 AM |
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But has anyone tryed it?
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BenB
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| posted on 3/8/08 at 09:21 AM |
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Have a shoofty at the Robin Hood lightweight shenanigans.....
Most SVA test centers refused to pass them as they were worried they wouldn't take the normal loads of road driving. Just think how yucky the
handling would be on a track (if it didn't twist itself up like a pasta twirl)....
That's not to say an ali chassis couldn't be made- but its seriously tricky....
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eznfrank
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| posted on 3/8/08 at 09:21 AM |
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Someone will have although whether they admit to it or not is a different matter.
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purdy
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| posted on 3/8/08 at 09:23 AM |
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that robin hood lightweight shananigans looks poo and is only a few kilos lighter than a erw frame!
its just a product for the unable....
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StevieB
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| posted on 3/8/08 at 09:28 AM |
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You can do it, but it needs to be a monocoque rather than a space frame.
The Elise is a good example, which was designed by the same guy who did the Renault Spider. He was obsessed with the concept of extruded aluminium
window frames and that their inherent strength could be applied toa car chassis.
There's a new book I'v e just bought called 'how to build motorcycle engines racing cars' which describes the various
components and considerations needed in designing and building such things. I has a section on how to make a monocoque chassis using honeycombali
panels and strong adhesive. Looks a fairly reasnoable concept, though it does require a ery thorough design up front as their are none of the
opportunities to go back and make changes like you can with a space frame (the author describes frustrations of having to scrap in faulty monocoques
for £0.75p/kg because he didn't mke certain considerations).
I would have to say that unless you've built a few spoace framed cars previously or have a lot of experience working with alloys, it's
probably best to stick to designs that have been previously tried and tested.
I have the same ideas, but I've built an Indy as my first car to get some practical experience. I'm going to have a crack at designing a
chassis, but it'll more than likely be a space frame chassis, despite my will to do something a bit different.
[Edited on 3/8/08 by StevieB]
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BenB
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| posted on 3/8/08 at 09:59 AM |
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"have a crack"- quite appropriate considering we're talking about ali chassis!!! 
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scootz
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| posted on 3/8/08 at 10:00 AM |
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Someone on here did make an ali spaceframe chassis... can't remember them making a great song and dance about how successful it was, so that may
give you an indication of how good an idea it is!
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Ivan
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| posted on 3/8/08 at 10:26 AM |
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The basic chassis is such a small percentage of the weight that it is difficult to make worthwhile savings in it. Much easier to make the savings in
component selection such as wheels, tyres, uprights, brakes, drive train, diff etc . (although expensive)
If you are serious about going all out to save weight look at the fancier high strength steels and a structural (FEA) redesign of the chassis to suit
the material - you might get away with smaller sections with better grade and section selection.
Of course if you choose the above path you better make sure your designer knows his materials and FEA processes and understands the life cycle
properties of the material selected and manufacturing processes and controls needed to weld (join) it. (This would apply to aluminium and Titanium
Carbon fibre, and rarium as well)
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rebelrider
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| posted on 3/8/08 at 11:16 AM |
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I asked the same Question a few months ago and after everone telling me it was not i good idea i went out and made it anyway lol.
i used 25 * 25 * 3mm ali which is still lighter the 25 * 25 * 1.5mm mild steel
The chassis is all done I havent got any futher yet though.
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purdy
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| posted on 3/8/08 at 06:27 PM |
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interesting reblerider
I feel the idea will work too, do you have any pics? and what do you think of the final example ie. The ridgidity of the frame?
purdy
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chrisg
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| posted on 3/8/08 at 07:13 PM |
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it will work - for a short time.
Welding creates a weak zone around the joints and when the frame flexes this area will work harden and crack. You can bolt all the sections together
but then you won't save any weight.
I only know of one hillclimb car that has an aluminium spaceframe and the owner "lifes" the chassis every half season, impractical for a
road car.
The only way to go aluminium is to build a Honeycomb monocoque, if it was viable then they'd proliferate, racers are fanatical about weight,
they'd have made it work and they haven't.
Sorry but it's a non starter and a criminal waste of money.
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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johnston
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| posted on 3/8/08 at 08:16 PM |
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I've used ali box section in work , mainly for making up and fixing hand rail up rights on powder tankers.
As said before is like cheese considering all it was doing it would break where drilled or welded . In the end we got that pee'd off fixing
the stuff we used to get the solid bar or stainless and just tell foreman the supplier was out of stock of box :p
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rebelrider
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| posted on 3/8/08 at 08:36 PM |
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ill take some pictures and post them when i get a chance i also thought about cutting chassis from flat sheet and forming the shape of the car
(instead of space frame) as i have lasers and i can program.
as for the waste of money its not a waste if you dont have to pay for the material 
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