----- Original Message -----
From: "Hamad Mannai" <a71aw@mail.com>
To: <towertalk@contesting.com>
Sent: Thursday, February 24, 2005 12:38 PM
Subject: [TowerTalk] Trying to build my own crank-up tower
> Hello All,
>
> I am trying to build my own 50 ft crank up tower (using 3 sections of 20
ft. each, 5 ft overlaping for the 2nd and 3rd sections). I did all the
drawings, measurements and weights which ables this tower to be free
standing. Now I am stuck with 2 major issues tobe sorted out :
>
> 1- Do I have to use any sort of (sleeve bearings) to avoid friction
between the sections while cranking up or down? or can I just make the
sections as tight as possible to each other to avoid free movements?
Not too tight, or it will bind and get stuck.
>
> 2- Whats the best way to distribute pullies through the sections to manage
the up and down mechanism?
It's sort of hard to describe in words. Say your sections are A, B, and C,
from bottom to top. The cable goes up section A to the top, where there's a
pulley, then down to the bottom of section B, where there's a pulley, then
up to the top of section B, where there's a pulley, then down to the bottom
of section C, where it attaches.
Fire truck extension ladders work the same way.
>
> I know I am asking too much, but I never saw a crank up lattice tower
closely. And I have to build it myself because its not availabe here and in
case of importing it from US/Europe, it will cost me $2000+ as shipping
charges only!!
>
I would think that drawings are available of some standard towers which you
could look at to get ideas.
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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