flak monkey
|
| posted on 9/3/05 at 12:16 PM |
|
|
Aluminium Spaceframe/Monocoque
Just to stir up this old hornets nest again....
I put this in here as its not really a Locost question.
I have read through all the old stuff about ally chassis' and am aware of the main issues with them; i.e. the fatigue and stiffness issues.
I am producing a design for a single seater race car, which will only see about 250hours use at max, before a rebuild.
This is only a concept design, so may not actually be built, so this is all research atm.
What i would like to know is if anyone knows of some good books/websites with some good info about ali spaceframes/moncoques. I was thinking of
possibly ali spaceframe with structural bodywork to regain some stiffness.
Im not looking for solutions, just some pointers toward useful info.
Or if you think its a really bad idea, tell me, as long as you can justify why...
Cheers,
David 
[Edited on 9/3/05 by flak monkey]
Sera
http://www.motosera.com
|
|
|
|
|
JonBowden
|
| posted on 9/3/05 at 12:32 PM |
|
|
Hi,
Others will be more able to suggest good books on design. However, if you want to use all aluminium, why not a rivited and bonded aluminium
monocoque.
Benefits:
better strength to weight ratio
cheaper - no steel chassis needed
looks cool
safer to crash (so I've heard)
more interesting challange
might be quicker to build (once the design is sorted)
[Edited on 9/3/05 by JonBowden]
Jon
|
|
|
DaveFJ
|
| posted on 9/3/05 at 12:35 PM |
|
|
you may be better looking for info on airframe design, this should be better suited to your needs.
Dave
"In Support of Help the Heroes" - Always
|
|
|
flak monkey
|
| posted on 9/3/05 at 12:37 PM |
|
|
Monocoque is definately a possibility. And i would like to know a lot more about them (as all my knowledge is currently of steel spaceframes...). But
i also need info for spaceframes too...
All good book/website suugestions appreciated, along with any personal opinions
Sera
http://www.motosera.com
|
|
|
JonBowden
|
| posted on 9/3/05 at 12:49 PM |
|
|
quote:
you may be better looking for info on airframe design
I agree, you might like to look at http://www.zenithair.com/zodiac/6-construct.html this
link shows construction of an aluminium aircraft.
Cars have one problem that is not such an issue with aircraft, the loads are applied at specific points where the suspension attaches. This is not a
problem with spaceframes but makes monocoque design a bit harder.
IIRC, Carol Smith discusses monocoque construction in Prepare to Win
Jon
|
|
|
JonBowden
|
| posted on 9/3/05 at 12:55 PM |
|
|
The lotus 25 is a simple design (I believe that it's not very stiff though)
 
Rescued attachment Lotus25-GB14.jpg
Jon
|
|
|
JonBowden
|
| posted on 9/3/05 at 12:56 PM |
|
|
Its really more like a ladder chassis
 
Rescued attachment FIG1.jpg
Jon
|
|
|
Volvorsport
|
| posted on 9/3/05 at 04:16 PM |
|
|
be wary of ally spaceframes , they may not be as light as you think , to get the same strength as a steel one , and suffer distortion more than any
other - a riveted/bonded monocoque is a much cheaper and better option spesh if you use honeycomb .
me of course would make a grp/kevlar one . make a simple u shape for me mold out of ally the lay up on it , chuck it on a jig , then bond in subframes
/scuttles/ bulkheads etc .
the book for you would be staniforths one of course .
[Edited on 9/3/05 by Volvorsport]
www.dbsmotorsport.co.uk
getting dirty under a bus
|
|
|
flak monkey
|
| posted on 9/3/05 at 06:03 PM |
|
|
I know the problem with acheiving the same rigidity form an ali space frame. But know very little about aluminium monocoques. Though i have heard
about the honeycomb stuff.
We dont have the facilities to make proper carbon fibre structures, so that has been ruled out.
What are the full details of the Stainforth book?
David
Sera
http://www.motosera.com
|
|
|
Volvorsport
|
| posted on 10/3/05 at 12:01 AM |
|
|
the race and rally car source book - its a build thing - . i lost my book to a mate - or else id tell ya .
you wouldnt necesarily need to do carbon fibre - id be happy to do you a quote to get you started .
www.dbsmotorsport.co.uk
getting dirty under a bus
|
|
|
wheelsinsteadofhooves
|
| posted on 10/3/05 at 09:08 AM |
|
|
check out "race car chassis design and construction" by forbes aird. shopuld be available from amazone or theres always motor books
(www.motor-books.co.uk). they have everything (apart from the stainforth suspension book at the mo).
chassis book covers all the options in detail with benefits/drawbacks. basic point re ali spaceframes is that although ali approx 3x lighter than
steel, you need about 3 time the amount for same strength (not stiffness - you could build a very stiff chassis out of paper but it would have no
strength), so you sort of loose what you gain with ali. monococques also discussed but in not so much detail, still more than enough to get going. as
mentioned smith's "prepare to win" series also covers monococques in some detail.
problem with fs is that if your using any fancy chassis design you have to theoretically prove its as strong as a spaceframe, which can be challenging
mathematically challenging.
good luck with the project
|
|
|
monocoque_nut
|
| posted on 7/8/05 at 05:09 PM |
|
|
quote:
Originally posted by JonBowden
The lotus 25 is a simple design (I believe that it's not very stiff though)
If you can search google about the lotus 25 chassis you will find that its lighter and stiffer then a spaceframe.
Nice picture though. I have been looking for something like this for weeks!
I suggest seraching for the lotus elise chassis. That would be easy to adapt to the locost layout. It blew my mind when i first read a about it.
Im planning to do that myself.
|
|
|
britishtrident
|
| posted on 7/8/05 at 06:00 PM |
|
|
The Lotus 25/33 was actually heavier than the Lotus 24 which apart from the fact it used a spaceframe was otherwise identical. The sole advantage of
he 25 monocoque over the 24 was its much greater stiffness.
|
|
|
