philipcurtis100
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| posted on 3/9/09 at 07:21 PM |
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ali spaceframe
im going to build a space frame out of aluminium
i just what to know what grade people think i should use
im using 3 1/2" tube 3mm thick wall
thanks
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blakep82
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| posted on 3/9/09 at 07:27 PM |
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the grade i would suggest is steel.
its been discussed loads on here, and generally isn't a good idea.
stress fatigue is a main cause. to make it strong enough if would need to be very thick, by which time its about the same weight as a steel one would
be
consider the response from your last thread about this  BAD IDEA
[Edited on 3/9/09 by blakep82]
________________________
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don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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aaron bassett
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| posted on 3/9/09 at 07:28 PM |
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dont go there lol only joking you will have to think of ali being brittle and for you to get the same strenth of steel you will have to make it as
heavy as steal. better making it as a monocoque out of alley
[Edited on 3/9/09 by aaron bassett]
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afj
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| posted on 3/9/09 at 07:34 PM |
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quote:
Originally posted by aaron bassett
dont go there lol only joking you will have to think of ali being brittle and for you to get the same strenth of steel you will have to make it as
heavy as steal. better making it as a mono cock out of alley
mono cock
eerrrrrrrrrrrrrrrr
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speedyxjs
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| posted on 3/9/09 at 07:35 PM |
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What are your reasons for wanting it ally? Is it just weight saving?
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deezee
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| posted on 3/9/09 at 07:45 PM |
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Can I have your engine and gearbox after it looks like spaghetti and you've given up?
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blakep82
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| posted on 3/9/09 at 07:48 PM |
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^ ah, heat distortion? hadn't thought of that
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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speedyxjs
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| posted on 3/9/09 at 08:01 PM |
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quote:
Originally posted by deezee
Can I have your engine and gearbox after it looks like spaghetti and you've given up?
You dont know what engine it is. For all you know it could be a bike engine 
How long can i resist the temptation to drop a V8 in?
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jambojeef
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| posted on 3/9/09 at 08:10 PM |
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Tell owners of ferrari 612s and 360s that ally spaceframes arent a good idea!
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DorsetStrider
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| posted on 3/9/09 at 08:25 PM |
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How do you intend to mount the suspension?
As I recall the robin hood lightweight was red flagged at SVA because it was discovered the ali brackets were not up to the job.
Personally having looked into this unless your going the mono cock route I'd advise using steel.
Who the f**K tightened this up!
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deezee
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| posted on 3/9/09 at 08:38 PM |
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quote:
Originally posted by jambojeef
Tell owners of ferrari 612s and 360s that ally spaceframes arent a good idea!
LOL ok, you send em around and I'll tell em. Although I can only half tell em, cos half their car is monocoque. Even though compared to the
355 the 360 is only 30kgs lighter. Not a lot more in a 1400 kg car.
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blakep82
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| posted on 3/9/09 at 08:57 PM |
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quote:
Originally posted by deezee
quote:
Originally posted by jambojeef
Tell owners of ferrari 612s and 360s that ally spaceframes arent a good idea!
LOL ok, you send em around and I'll tell em. Although I can only half tell em, cos half their car is monocoque. Even though compared to the
355 the 360 is only 30kgs lighter. Not a lot more in a 1400 kg car.
plus i bet ferrari spend a lot of money on R&D for their mono cock chassis. a few hundred thousand maybe? well, a bit more than asking on a
forum, thats for sure
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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Ivan
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| posted on 3/9/09 at 09:01 PM |
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Why settle for aluminium when, with the same amount of research, and for possibly much less risk of fatigue failure, you can go for Carbon Fibre and
really have bragging rights - and end up with a lighter chassis.
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philipcurtis100
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| posted on 3/9/09 at 09:27 PM |
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motorbikes r made out of ali they dont brake or bend etc
i just wanted suggestions of grade to use
not
steels better bla bla bla
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Staple balls
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| posted on 3/9/09 at 09:58 PM |
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quote:
Originally posted by philipcurtis100
motorbikes r made out of ali they dont brake or bend etc
i just wanted suggestions of grade to use
not
steels better bla bla bla
Okay, tell me how a motorbike's frame design translates into a car's spaceframe.
The alu route has been discussed many, many, many times, and I'm not sure anyone makes an alu spaceframe (I think mk used to, but only for
track use)
Really, there's no sensible reason to make make a locost of of alu, it's just not suited to the job.
[Edited on 3/9/09 by Staple balls]
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Canada EH!
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| posted on 3/9/09 at 09:59 PM |
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Do you have the same heat treating ovens as Ferrari, to normalize the chassis once it is all tig welded together?
Also do you want to bend and twist the first one to see how it handles stress?
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DorsetStrider
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| posted on 3/9/09 at 10:14 PM |
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quote:
Originally posted by philipcurtis100
motorbikes r made out of ali they dont brake or bend etc
i just wanted suggestions of grade to use
not
steels better bla bla bla
Once more I'd like to refer you to the robin hood lightweight. How do you propose to mount the suspension on an ali spaceframe in order to get
it throu the IVA? or is this a track only car?
Who the f**K tightened this up!
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liam.mccaffrey
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| posted on 3/9/09 at 10:25 PM |
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this is a wind up OR you work in the office and you have miss understood your more technical colleagues advice.
Trust me they didn't mean for you to build an ali space frame. A motorbike chasis is not a spaceframe. A casting is not a spaceframe
EDIT
An ali motorbike frame isn't a spaceframe
[Edited on 3/9/09 by liam.mccaffrey]
Build Blog
Build Photo Album
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blakep82
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| posted on 3/9/09 at 11:23 PM |
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quote:
Originally posted by philipcurtis100
motorbikes r made out of ali they dont brake or bend etc
i just wanted suggestions of grade to use
not
steels better bla bla bla
you're not going to get suggestion on what grade to use because its a terrible idea.
you're getting 'steel's better bla bla bla' because, steel is better. simple as that
out of both your threads on the subject, the response has been the same
[Edited on 3/9/09 by blakep82]
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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nitram38
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| posted on 4/9/09 at 04:36 AM |
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I don't want to poo poo your idea, but I worked for 5 years in a welding and fabrication workshop. I have welded both cars and bikes.
There are cars that have used aluminium chassis but the problem with it is that it is a crystaline metal which means that it fractures easily
compared to steel.
To get over this, the ali is thicker or cast into required shapes.
The structure bending under welding is also an issue as it seems to pull more than steel.
For the amateur builder, stay with steel, because you will not even notice the power to weight gain from a slightly lighter chassis.
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scootz
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| posted on 4/9/09 at 07:04 AM |
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If it was a viable option, then you can bet your boots that most kit-manufacturers would be selling them right now.
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907
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| posted on 4/9/09 at 07:15 AM |
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Welded Fabrications
When metal solidifies it forms into crystals that are more or less equal in shape and size.
Diagram A shows this in simple form. Aluminium in this form is low in tensile strength. (Soft)
When it is made into usable shapes in the mills it's rolled and extruded while it's cold,
and this squashes the crystals as in diagram B.
In this form the tensile strength is much higher. In sheet form this is what is termed "half hard".
Further cold working increases the tensile strength even more, like the ali angle that you can buy in Homebase for instance.
When metal is welded it re-crystallizes from B back to A, and also the surrounding area, the heat affected zone. (HAZ)
Aluminium is a fantastic conductor of heat so the HAZ is huge, so in a welded fabrication we have high strength areas
and very soft areas, the red bits in diagram C.
This is why cars that use ali in there construction are riveted, bolted or glued, and not welded. e.g. Lotus.
It's more complicated than this but this may go some way to explain.
Cheers
Paul G
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02GF74
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| posted on 4/9/09 at 01:12 PM |
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forget aluminium mono cock, make it from tit anium.
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200mph
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| posted on 4/9/09 at 01:39 PM |
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F*ck it - go make it out of gold
It seems you're looking for an answer that you want to hear, rather than the right answer.
If so, why ask the question in the first place?
I'll ask my dog and see what grade he suggests.
Edit: my dog says to use steel....
[Edited on 4/9/09 by 200mph]
If it isn't broke, fix it until it is
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kb58
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| posted on 4/9/09 at 03:30 PM |
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quote:
Originally posted by 907
...Aluminium is a fantastic conductor of heat so the HAZ is huge, so in a welded fabrication we have high strength areas
and very soft areas, the red bits in diagram C...
And to take this one step further, once the aluminum chassis is done, it'll be very weak due to all the HAZ areas. Unless it's properly
heat-treated, the resulting assembly is a waste of time and money.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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