philipcurtis100
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| posted on 20/8/09 at 05:38 PM |
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space frame
hi im phil
i wanna build a space frame for a mini fiberglass shell i wanna make it out of aluminum what size tube should i use and what wall thickness
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blakep82
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| posted on 20/8/09 at 05:55 PM |
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i think i'd really advise against aluminium tube space frames.
________________________
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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tegwin
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| posted on 20/8/09 at 06:02 PM |
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Have a quick search on here for threads on alloy chassis...
IMHO, no manufacturor makes a space frame alloy chassis... they are all welded/bonded monocoques.....
A well thought out steel spaceframe can be as light and as stiff as a similar alloy tub, unless you have a LOT of experience and know where to save
weight on your alloy chassis!
------------------------------------------------------------------------------------------------------------------------
Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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blakep82
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| posted on 20/8/09 at 06:06 PM |
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i think i seem to remember a comparison between a steel chassis, and an equivalent aluminium space frame chassis, and there was no weight saving.
i think...
________________________
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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brianthemagical
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| posted on 20/8/09 at 10:07 PM |
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There's very little to be gained from the use of Ali in a well designed chassis. Most of the members should be in compression or tension, and
therefore, especially with the relatively thin walled, large dia, tubes used, Ali will offer little gain, for an increased cost. Ali also has much
greater fatigue problems, which make long term use a pain.
Ali can be much better for use in bending situations. Most common materials have similar E/density, thus for a given mass, they'll have a
similar specific E, but the incresed material needed for lower density materials affords much better designs.
The best chassis would be a CFRP shell, modified a bit for extra stiffness where needed. Either that, or wood's better than ali and steel.
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philipcurtis100
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| posted on 22/8/09 at 02:07 PM |
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i have decided to make it out of ali but i dont know what size tube and wall thickness to use
i was thinking 3 1/2" tube with 3mm wall thickness would this be ok?
thanks
phil
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cymtriks
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| posted on 22/8/09 at 08:58 PM |
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Everyone is telling you the same thing. Ali is harder to weld and won't weigh less for a spaceframe. There are fatigue issues as well.
However considering the tube size you just mentioned you geting very close to a size that could be used in a simple X braced ladder frame. Weight for
weight and with the right choice of tube size you might beat most steel spaceframe this way. Ladder frames are no where near as bad as some would have
you think and going to Ali would tip the balance in your favour. However to do this you would need to select the right tube size and weld it up
properly and consider the fatigue issues and any corrosion issues and any issues from Ali being in contact with steel bits (which makes ali rot away).
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brianthemagical
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| posted on 22/8/09 at 09:41 PM |
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One option for determining tube sizes may be to equate it to a similar steel item. Either a similar weight, or use sutible specifications for a steel
chassis or cage, maybe FIA specs and then use equivilant spec Ali.
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kb58
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| posted on 23/8/09 at 01:19 AM |
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Speaking of welding it correctly, what specs will be used for heat-treating the chassis? If this is unknown, it's a sign that serious reading is
in order.
Speaking of that, asking here about something as serious as aluminum chassis design is an iffy proposition. That's somethat that should be
researched in books, not asking strangers about something where your life will be on the line...
I'd like to see the chassis fatigue life calculations on the chassis before it's started, if you don't mind.
[Edited on 8/23/09 by kb58]
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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philipcurtis100
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| posted on 25/8/09 at 05:42 PM |
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its only a bit of fun
if it breaks it breaks
ill just do it an see
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MikeR
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| posted on 25/8/09 at 06:11 PM |
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Cool - good luck with the project. Love your enthusiam.
Out of curiosity, what will you do when it breaks, you crash into a bus stop full of people and kill a few of them?
Perhaps you'll be on a track and demolish someone else's car whilst skidding out of control - hopefully you won't kill them, will
you rebuild their car for them?
Yeah, i'm being harsh - but consider the implications of your actions on others as well as yourself. I'd put a wager on the fact
you're not an expert otherwise you wouldn't be asking these questions. Everyone is telling you its complicated and you need to read up
more - either follow the advice and make an educated decision yourself or make it out of steel.
(i'm in a grump, i've got a pounding headache from welding steel all day and breathing the fumes).
Oh, read up on porsche race cars - they made one out of Ali (907 / 913? not sure) and read about the problems they had.
edited to add - its the 917
and to correct myself, the 908 is where they started ali frames
[Edited on 25/8/09 by MikeR]
[Edited on 25/8/09 by MikeR]
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philipcurtis100
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| posted on 25/8/09 at 09:11 PM |
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Out of curiosity, what will you do when it breaks, you crash into a bus stop full of people and kill a few of them?
Perhaps you'll be on a track and demolish someone else's car whilst skidding out of control - hopefully you won't kill them, will
you rebuild their car for them?
it would be tuff they shouldnt get in the way
it prob wont be finnished i get bored easily
i have been told by collegues that ali is what i should make it out of
we make ali castings for automotive firms (aston martins, jags, metc, bmw, ford,etc)
so i think ali is perfect
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Mark Allanson
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| posted on 25/8/09 at 09:15 PM |
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Stunned silence
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Staple balls
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| posted on 25/8/09 at 09:16 PM |
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quote:
Originally posted by philipcurtis100
it would be tuff they shouldnt get in the way
it prob wont be finnished i get bored easily
i have been told by collegues that ali is what i should make it out of
we make ali castings for automotive firms (aston martins, jags, metc, bmw, ford,etc)
so i think ali is perfect
If you worked for a bakery, would you be making it out of bread?
Aluminium is great, in the right applications, when designed properly, welded well and heat treated. if you do it wrong, you'll have a very
expensive deathtrap.
Steel is well proven for car spaceframes, pretty cheap, and doesn't need any pissing about with, you just need to be able to weld passably.
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James
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| posted on 4/9/09 at 11:33 AM |
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quote:
Originally posted by Staple balls
If you worked for a bakery, would you be making it out of bread?
ROTFLMAO!
Beautiful!
------------------------------------------------------------------------------------------------------------
"The fight is won or lost far away from witnesses, behind the lines, in the gym and out there on the road, long before I dance under those lights."
- Muhammad Ali
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iank
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| posted on 4/9/09 at 01:48 PM |
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Go on do it, will give the IVA inspectors something to talk about during the tea break. Then you can try to rebuild the whole thing again from
scratch from steel before the retest period expires.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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wilkingj
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| posted on 4/9/09 at 02:12 PM |
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quote:
Originally posted by Mark Allanson
Stunned silence
Ditto... and I thought I was a bit irresponsible!
1. The point of a journey is not to arrive.
2. Never take life seriously. Nobody gets out alive anyway.
Best Regards
Geoff
http://www.v8viento.co.uk
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kb58
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| posted on 4/9/09 at 03:46 PM |
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quote:
Originally posted by philipcurtis100
i have decided to make it out of ali...
So will it be built upon sound engineering data... or emotion and ignorance? The resulting chassis will reflect it, being fussy, lazy, and
failure-prone.
(Actually I'm beginning to suspect the OP is a troll, just stirring up people here for the entertainment value.)
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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philipcurtis100
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| posted on 4/9/09 at 04:38 PM |
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well the entertainment is very good from this topic
but i think ill make it and see what happens for myself
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Benzine
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| posted on 4/9/09 at 04:50 PM |
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kb58
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| posted on 4/9/09 at 10:42 PM |
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unsubscribe
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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philipcurtis100
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| posted on 5/9/09 at 11:42 AM |
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what do you mean
i have joined for some usefull info and all i get is use steel
has anyone used ali
im just after usefull info about ali
if you only know steel dont reply
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Staple balls
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| posted on 5/9/09 at 11:48 AM |
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I think it's quite obvious a lot of people here know plenty about aluminium, which is why you're getting told to use steel.
You could use aluminium, no doubt, but it's expensive, unsuited to the job, and all round a bad idea, hence everyone telling you to use
steel.
Now, you're either incapable of seeing sense and building a car that'll work, or terrible troll. I'd suggest you toddle off and do
something else, duplo might be more suited to your level.
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philipcurtis100
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| posted on 5/9/09 at 12:03 PM |
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im after info about ali so thanks for the useful reply 
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prawnabie
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| posted on 5/9/09 at 12:48 PM |
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If you want to go ahead and use ally thats fine. I cannot see anyone chipping in on a project that might go horribly wrong and come back on them!
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