http://www.pistonheads.com./sales/1168507.htm
[Edited on 16-12-09 by mangogrooveworkshop]
Just seen this bec with some nice bones
http://www.pistonheads.com./sales/1168507.htm
[Edited on 16-12-09 by mangogrooveworkshop]
hmm, someone on here wanted to make ali wish bones yesterday, and we all said it was a bad idea. this makes a interesting twist on things... maybe its not as bad as we thought then
Pretty but try getting those through an IVA with those edges!
yeah but notice: "Only one other for sale in the UK. Six years in the making. "
doesn't look registered or used for that matter so not much testing could have been done on it.
quote:
Originally posted by Nash
Pretty but try getting those through an IVA with those edges!
Nothing wrong with making them that way but you need to know how to engineer them properly to stop fatigue being an issue, not really a low-cost
option..
Personally I'd still stick with steel it's more forgiving, they are mission critical parts... But this is because I am not a trained
engineer...
Dan
i cant see the problem with ali wishbones. my vauxhall estate has ali wishbones.
Think we better warn this lad its a bad idea
http://www.ferron.nl/nieuws/news_us.asp
He has pretty much done the whole car in the stuff.... nice work
ps before any one gets the humph I do understand the reasons for the avoidance of ali in certain engineering designs
ali wishbones are fine if properly engineer, but should be forged not machined
[Edited on 16/12/09 by liam.mccaffrey]
^^ indeed, my old push bike gives away the problem, the ali cracked after about 20 years, o.k on push bike with a life < 20 years but on a car
this will happen quickly unless designed correctly...
Dan
nice for show, but i wouldnt like to have that shock mounted on such a week point and im not keen on the matL rmoved from the rears.....
Ali wishbones will be Ok if machined from solid and heat treated.
By the time they are properly designed taking fatigue into account would they be any lighter?
I don't know but suspect not
Nice uprights though
Shiny and machined doesn't always equal good engineering. The wishbones look to be hollowed out from the inner edge making them a sort of
c-section. Good for twisting and buckling if you asked me. Stronger lighter wishbones could undoubtedly be made from steel tube, but I guess this
guy likes using 3D CAD to design parts for machine-from-billet. Very shiny though.
Liam
[Edited on 16/12/09 by Liam]
Nothing wrong with making all the bits from ali... just ensure good design from the start... get your stress analysis books out and dont just rely on
FEA. looking into fatigue life and cyclic loading should give an idea of part lifetime but i guess ali parts are more suited to race and track
situations than 20 years use on the road... Forged should be stronger weight for weight.
A design thats strong enough will be lighter, a design thats strong enough and will last 20 years may not be. Ali doesnt have the flexibility of steel
that allows for long term cyclic stressing.
Those wishbones on the bec thing at the start of this thread, would be heavier than steel items of the same strength doing the same job.
All ali parts in racing, and more particularly the aviation industry, are 'lifed'. They just don't last as long as steel, even though
they save weight.
As far as 'strength/weight', there's only a couple of alloys in ali made that will outlast steel in cyclical loaded conditions, and
they can be considered 'unobtainium' for everyday man's purposes.
Everything has it's place, as to fitness for purpose and ease of fabrication.
Cheers,
Nev.
quote:
Originally posted by designer
Ali wishbones will be Ok if machined from solid and heat treated.