[TowerTalk] Rohn TB-3 Warning
Jerry K. Liley
k0gug@juno.com
Tue, 28 Oct 1997 18:50:57 -0600
Hi Eric,
Are we getting confused about the difference between thrust bearings
and ""THRUST BEARING CENTERING BOLTS"".....?
Stan wrote:
> So, I was wondering how you came to the conclusion that the"" Rohn
>TB3 bolts"" should not be relied upon to support the mast and antenna
>weight?
I think we can
all agree that the purpose of the thrust bearing is to carry the weight
of the mast and the antennas. Then the object is to apply that weight
to the race of the thrust bearing in the most positive manner. A clamp
of some kind above the bearing, held tight to the mast, would seem
to apply that weight more effectively than horizontal bolts. The
shear
factor on the bolts from the "SIDE" force is the potential problem. I
wonder what Rohn says......?
73, Jerry Liley, K0GUG, Holts Summit, MO
***********************************************************
On Tue, 28 Oct 1997 10:44:00 -0800 "Woods, Eric D (pb-Edwoods)"
<edwoods@pbsac01.isp.pacbell.com> writes:
>OK, let me show my ignorance. I thought that the intent of a thrust
>bearing on a tower was to take the vertical load off of the rotator.
>Eric, K6GV
>edwoods@pacbell.com
>
>(just another EE who had to take Strength of Materials in his junior
>year)
**************************************************************
> So, I was wondering how you came to the conclusion that the Rohn
>TB3 bolts should not be relied upon to support the mast and antenna
>weight?
>Just your own observation or did you read something from Rohn about
>this? I
>don't disagree with your conclusion, I just wonder if Rohn ever said
>anything about using other clamps above and below the bearings to
>support the weight.
>Stan w7ni@teleport.com
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