Supporting structures made out of tubes (was Lunar elevators made ou

>> Rocket fuel-tanks are made out of metal, so there's a convenient source of supply for building materials.
> Couldn't agree more. Now if we just had the in-space manufacturing capability to melt down a fuel tank and change the alloy to something more ductile and then draw the threads to make the cable and then twist a cable.

I was referring to the massive and bulky supporting-structures that every space elevator requires around its midpoint. Generally, these are proposed to be formed out of the very same exotic materials that would form the ribbon or cable at its most extant points. You don't think a rocket fuel-tank tube is a convenient shape for a piece of supporting-structure?:
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