Keystock as Lathe Bits ?

Okay. What are the highest strength/weight ratio materials? Some carbon variation, most likely. Boron fiber is cool, too. I tried a fly rod made from that stuff once. It's incredibly stiff and very strong.

But I doubt if music wire is going to be om the mix. At the extreme, in the finest diameters, its ultimate tensile strength can range up to 460,000 psi. In the thicker sections, around 1/8" dia., it's around 200,000 psi. But, being steel, it's heavy.

Reply to
edhuntress2
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Oops, 5000 kilometers: Shoulda looked it up first.

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"An untapered space elevator cable would need a material capable of sustaining a length of 4,960 kilometers (3,080 mi) of its own weight at sea level to reach a geostationary altitude of 35,786 km (22,236 mi) without yielding."

--jsw

Reply to
Jim Wilkins

"Jim Wilkins"

How do you apply "centrifugal force" to this counterweight? The satellite wants to travel in a straight line but is drawn toward the earth by centripetal acceleration, "gravity". Art Clarke is full of bullshit. There is _no_ force whatsoever acting outward. The cable is pulling inward toward the center of rotation.

Reply to
Phil Kangas

OK, "Centrifugal Force" is really straight-line inertia that acts along the object's instantaneous tangential velocity vector, not radially outward from the center of rotation. It only seems that way to the rotating observer who released the object.

The point is that the outer end of the cable beyond GEO is dragged around once per day while the unconstrained angular and orbital velocity of a satellite there would be slower, so the net force on the cable is outward.

--jsw

Reply to
Jim Wilkins

Well, the spring punch test was worthless. The pieces that look like keystock are easily scratched with a file, and the piece that looked like a manfacturer lathe blank isn't. I compared it to some M2 blanks I have and it seemed to skate the file about the same, but the indeterminate results of the spring punch come immediately to mind.

For those commenting on rust... these came to me in their current condition. The box was with other bits and pieces on a shelf on a covered patio. While Arizona is pretty dry its not completely dry.

Reply to
Bob La Londe

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