Printable Version | Subscribe | Add to Favourites
<<  1    2  >>
New Topic New Reply
Author: Subject: space frame
philipcurtis100

posted on 20/8/09 at 05:38 PM Reply With Quote
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

View User's Profile E-Mail User View All Posts By User U2U Member
blakep82

posted on 20/8/09 at 05:55 PM Reply With Quote
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!

View User's Profile View All Posts By User U2U Member
tegwin

posted on 20/8/09 at 06:02 PM Reply With Quote
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

View User's Profile Visit User's Homepage View All Posts By User U2U Member
blakep82

posted on 20/8/09 at 06:06 PM Reply With Quote
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!

View User's Profile View All Posts By User U2U Member
brianthemagical

posted on 20/8/09 at 10:07 PM Reply With Quote
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.

View User's Profile View All Posts By User U2U Member
philipcurtis100

posted on 22/8/09 at 02:07 PM Reply With Quote
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

View User's Profile E-Mail User View All Posts By User U2U Member
cymtriks

posted on 22/8/09 at 08:58 PM Reply With Quote
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).

View User's Profile View All Posts By User U2U Member
brianthemagical

posted on 22/8/09 at 09:41 PM Reply With Quote
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.
View User's Profile View All Posts By User U2U Member
kb58

posted on 23/8/09 at 01:19 AM Reply With Quote
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

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
philipcurtis100

posted on 25/8/09 at 05:42 PM Reply With Quote
its only a bit of fun
if it breaks it breaks
ill just do it an see

View User's Profile E-Mail User View All Posts By User U2U Member
MikeR

posted on 25/8/09 at 06:11 PM Reply With Quote
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]

View User's Profile View All Posts By User U2U Member
philipcurtis100

posted on 25/8/09 at 09:11 PM Reply With Quote
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

View User's Profile E-Mail User View All Posts By User U2U Member
Mark Allanson

posted on 25/8/09 at 09:15 PM Reply With Quote
Stunned silence





If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation

View User's Profile Visit User's Homepage View All Posts By User U2U Member
Staple balls

posted on 25/8/09 at 09:16 PM Reply With Quote
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.






View User's Profile Visit User's Homepage View All Posts By User U2U Member
James

posted on 4/9/09 at 11:33 AM Reply With Quote
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

View User's Profile View All Posts By User U2U Member   James 's Aim
iank

posted on 4/9/09 at 01:48 PM Reply With Quote
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

View User's Profile View All Posts By User U2U Member
wilkingj

posted on 4/9/09 at 02:12 PM Reply With Quote
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

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
kb58

posted on 4/9/09 at 03:46 PM Reply With Quote
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

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
philipcurtis100

posted on 4/9/09 at 04:38 PM Reply With Quote
well the entertainment is very good from this topic

but i think ill make it and see what happens for myself

View User's Profile E-Mail User View All Posts By User U2U Member
Benzine

posted on 4/9/09 at 04:50 PM Reply With Quote







View User's Profile View All Posts By User U2U Member
kb58

posted on 4/9/09 at 10:42 PM Reply With Quote
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

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
philipcurtis100

posted on 5/9/09 at 11:42 AM Reply With Quote
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

View User's Profile E-Mail User View All Posts By User U2U Member
Staple balls

posted on 5/9/09 at 11:48 AM Reply With Quote
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.






View User's Profile Visit User's Homepage View All Posts By User U2U Member
philipcurtis100

posted on 5/9/09 at 12:03 PM Reply With Quote
im after info about ali so thanks for the useful reply
View User's Profile E-Mail User View All Posts By User U2U Member
prawnabie

posted on 5/9/09 at 12:48 PM Reply With Quote
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!
View User's Profile View All Posts By User U2U Member
<<  1    2  >>
New Topic New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.