>?:" wrote:
>
> Steve Jackson wrote:
> > I need the aluminum because I have a weight restriction, and steel is just
> > too heavy for my application. I am fully aware that this material runs $40
> > a foot, versus chrome-moly 4043 at $20 or so.
> i also need an aluminum mast about 20 to 24 feet for the same reasons.
> up where i have my hf site i am the only one to do it and at my age
> cn't handle the weight of steel on the tower. please post answers to
> the reflector . jerry n6ifw
Most of these exotic-alloy heavy mast solutions are driven by the 2" diameter
limit for which most common rotators are designed to keep the mast axis
centered.
I am using a 2-1/2" flanged bearing at the top of my tower ($2 surplus, even
has
a grease fitting) with an adaptor machined and installed at the rotor end of the
mast to shrink it to 2". Mast strength goes up, I believe, as the cube of the
diameter. A small increase in mast diameter provides a huge bending-strength
increase.
Two-and-a-half inch dia by quarter-inch wall aluminum tubing might be readily
available.
Worth checking into, the mast would be even less weight...
<feel lucky? -- Make My Day>
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