bill shoe wrote:Brian-
Somehow I didn't see this thread until today. I occasionally write posts, and when I do I give some opinion about such and such thing, pretty mild. Your original post here is a really impressive lump of substance. Thanks.
You are welcome Bill.
Just having a fast skim read as Ive been missing a while,
Few other fab methods to consider -
Uprights, Titanium lost wax is common on a lot of parts Incl some gearbox parts.
Touching on the artwork of AL bike frames, hydroforming is another to consider also for such fabrications(pushrods and stuff).
The benefit of hydro forming is that because internal psi is constant over all surfaces internally, the metal will deform/comply to tool at a constant rate too - meaning uniform wall thickness - meaning less stress points where thickness changes - meaning you can start with a thinner sheet as you could if you were form stamping parts - with form stamping, the material will draw at a different rate ,leading to thin areas, and thick ones. This normally means an over than adequate thickness is selected to cover your ass on the thin draw areas.
Mercedes did just this on the new SLR to save weight over conventional cold forming mono sections. The hyroform method allowed them to use thinner AL sheet, and they made a pretty large(ish) weight saving.
Picture this too, if you have two strips of AL say 3'' x 20'' you can weld them both together both at the edges to seal, and in a parallel to long edges down along middles say, 4 lines of weld.
Once inflated, you are left with a XXXX internal cross section as the welds hold plates together where they are welded through.
Sorry for the hurried post, Ill fill in the blanks again, its late, and its been a long day, I came on this by accident when googling for something else., its always mad when you meet yourself on the internet.