The rollers are probably the least of your problem, but for a typical solution,
see the video at:
Pause it when they show close-ups of the rollers. They use two shaft mounted
rollers in a u-channel at the bottom and top of each leg tube. Something
similar to: http://www.mcmaster.com/#guide-rollers/=6euwew would work. The
main concern would be static load rating and weathering. A stainless steel
grooved sleeve bearing and shaft might work also, if lubricated frequently.
You would need rollers rated for at least 20,000# static load (assuming two per
The challenge is to maintain tight tolerances on leg straightness and spacing
so the telescoping sections are loose enough to not bind when under a
significant wind load and yet tight enough that the top section doesn't deflect
excessively during gusts. Powered pull-down would be required.
This is less of an issue with shorter nesting section that with a single 75'
section. 55G won't handle the wind loading unguyed and would bend too much to
allow it to retract reliably.
Date: Sat, 27 Mar 2010 17:15:12 -0500
From: Stan Stockton <email@example.com>
Subject: Re: [TowerTalk] Homebrew Crank-up
To: "Tower and HF antenna construction topics."
As mentioned the lower section would be large (33 inch face) tower
with 3 inch diameter legs. The top would either be 55G or 65G. I'm
interested in ideas for rollers, etc. Not worried about whether it
will stay up or not. There would be guy wires on lower section.
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