Cheers
Chris
Does it make much difference weather you use seamed or seamless tubing for the wishbones?
Seamless is stronger right? But can you get away with seamed?
If I were you I would try and get some DOM tubing. Not only is seamless DOM stronger because of the cold working but also a higher grade of steel is usually used. Can't be too safe when it comes to suspension.
it seems quite hard finding seamless tube, does anyone know if seamed will be strong enough.
I've seen a pic in the book where the trailing arms are made using seamed tubing, and also some people on this site use seamed oval tubing???????
Hydraulic supply places usually have seamless.
Cheers
Chris
any decent steel stockholder should have CDS (cold drawn seamless) that's what i have used for mine, 25mm O/D 18swg but the wishbones tiger supplied me (not using them) are a lot heavier i am guessing they are 10swg and i believe they are seemed...
oh and i paid £12.00+vat for 6 mtrs
I'm using the same seamed oval that MK uses on his wishbones. I rather doubt it's gonna just fall apart, probably not even in an accident that rips a
wishbone off - then it's academic anyway. I'm not worrying about using seamed.
I will, however, be getting my wishbones professionally [TIG] welded. That's something really worth thinking about. The quality of
welding is far, far more critical than the seamed-vs-cds issue when it comes to the wishbones.
IMO of course.
Liam
[Edited on 19/12/02 by Liam]
Of the seamless "mild" steel tubing, CDS is the strongest, followed by CDW/DOM.
Then there is welded mild steel tube (ERW), which shouldn't be confused with black/galvanised pipe, which is also welded. You should only be using
tube.
You could use ERW, but it would be worth doing a few sums first to check suitability. I would have thought 25.4mm x 2.6mm ERW would do the job.
I would only use CDW/DOM and CDS. It's dimensionally more acurate, and inherently stronger. OMO.
quote:
Originally posted by chrisg
Hydraulic supply places usually have seamless.)
I must admit that I was just going to use ERW like the rest of the chassis (but round obviously). If you stick a bit in the vice and bash F*** out of
it (Highly technical I know and perhaps taking the technological approach too far. ) you can cause more damage than I would want to see on my car and
it's primary failure mode doesn't seem to be one of falling apart at the seams.
Now I know that this probably is only an approximation of the wishbone loadings on a locost but it indicates to me that the welded seam is probably
not too much of a problem. If we were applying pressure from the inside it might be a diferent thing - but we are not.
Once again I might be talking rubbish but your views would be appreciated.
Phil.
quote:
Originally posted by philgregson
Now I know that this probably is only an approximation of the wishbone loadings on a locost but it indicates to me that the welded seam is probably not too much of a problem.
Guys consider a seamed tube that has come "unseamed" unlikely, but bear with me.
I t will stiil have the same tensile strength as full tube and the full compressive strength. The three things that are afected adversly are a)
torsional stiffness, b)beam stiffness, and c) buckling strength.
Consider a), this should not be an issues, as there should be no torsional loads on any wishbone tube.
b) again should not be an issue, there are no bending loads (except for the lower wishbone I guess)
c) depends a lot on the tube length. a relatively short tube with a thick wall should not be affected too much.
So I would say with a good choice of material, seamed tube should be OK IMO. Although DOM/seamlees is better.
I'd also agree with Liam that quality of welding is a bigger concern than tube selection.