David et al:
Self-supporting tower bases without leveling nuts have to be installed
with the bottom tower section installed so you can plumb that first section.
You can't just bury the base legs in concrete and expect to be able to ensure
that subsequent sections will be plumb.
I did the same as Bill when I installed by SS tower. I attached the
bottom section to the base legs and suspended it over the hole on a lumber
frame. I then plumbed that first tower section and ensured that it didn't move
while the concrete was being poured.
I plumbed that bottom section by suspending a plumb line (string with a
heavy wrench on it) from a T-shaped wooden frame setting on top of the bottom
section (per K7LXC's suggestion). I sighted from one face of the tower, through
the tower, and lined up the plumb line along one edge of the tower leg opposite
the face. I adjusted the shims underneath the wooden frame supporting the
bottom section to make that string parallel with that one leg. I moved around
the tower, sighting through each face to the opposite tower leg, adjusting the
supporting frame as I went along.
If anyone wants a copy of the T-shaped frame in use atop my tower's first
section, drop me a note. I haven't uploaded it to my photo pages yet.
73 de
Gene Smar AD3F
From: Bill Turner <dezrat@copper.net>
Date: 2008/01/22 Tue AM 09:15:49 CST
To: David Gilbert <xdavid@cis-broadband.com>
Cc: towertalk <towertalk@contesting.com>, Its from Onion <aredandgold@msn.com>
Subject: Re: [TowerTalk] Plumbing a tower
ORIGINAL MESSAGE:
On Mon, 21 Jan 2008 23:16:53 -0700, David Gilbert
<xdavid@cis-broadband.com> wrote:
> but as I mentioned I
>was installing a free-standing tower where the base gets embedded in
>concrete long before the rest of the tower is added. The base sticks
>barely a few inches out of the ground, so I don't think a transit is the
>right tool for that job.
------------ REPLY FOLLOWS ------------
When I put up my 80-foot self supporting tower, I bolted the first
section to the stubs and built a framework to suspend that in mid-air
over the hole. I plumbed that before the concrete was poured and
double and triple checked it for plumb as the concrete was setting. A
week later I installed the rest of the tower and it was dead on.
73, Bill W6WRT
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|