> 1. Tower - The tower is a 20 year old used 73' US Tower (Model
HDX-572)
in fairly good condition. Before starting the installation, I will pull
it apart, replace the pulley sheaves and wire ropes as well as wire
brushing and spraying on a coat of high-zinc content cold galvanizing
paint. (It has a prop pitch motor for a rotator).
Congratulations on your project. Should work great when you're done.
The question is "Is it worth the effort to replace the sheaves, cables
and galvanizing?"
I would be skeptical of replacing the sheaves and cables. I have
worked on dozens of crank-ups over the years and I have yet to see one that
required the work you're suggesting.
There are 3 reasons to replace the cables (these are all covered in my
tower book): 1) Excessive broken strands. Industry specs say you can have
6 broken strands before replacement is recommended. 2) Excessive rust.
Cancerous rust - not surface rust. 3) Damage. This would be kinks or flat
spots
in the cable.
If you don't meet this criteria, then it's more psychological than
real benefit.
As far as using cold galvanizing paint, it's a band-aid but again
offers more psychological benefit. Hot dipped galvanizing will last 20-30
years
or more while the cold galv spray is only good for several years.
UST uses sealed bearings pressed into their sheaves. I have yet to run
into one that was fatally overworked to the extent that it needed
replacing. In the old days the sheaves just turned on bushings that did
eventually
develop problems. Remember the pulleys are only worked occasionally and at
slow speeds so it'd take a lot of work to wear one out.
Please don't let me discourage you from this project but I just wanted
to offer a different perspective for the amount of work you're proposing.
If you're looking for a project, then knock yourself out.
In any case you'll have fun in the end so whatever you do, it'll be
worth it.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for amateurs
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