[TowerTalk] Summary of responses "weight on rotator"

jack colson jackcolson@x-press.net
Wed, 15 Sep 1999 10:22:33 -0400


Hi Jack,
The common wisdom is that the rotor is designed and should support the
weight
of the mast and antenna. That said, I have had a 4-el quad (24 foot
boom) up
on a Tri-Ex HD3-54 crank up tower for over 30 years that is
weight-supported
by the TB-2 thrust bearing and the bearing still turns smoothly. Total
weight
of antenna and mast is about 105 lbs. The rotors are Ham IVs. I say
rotors
because I've put a few in over the years because the Midwest winds have
torn
up the brake and gears.
Hope this helps and good luck,
Joe, K�JN

---------------------------------------------------------------------
Jack,

I prefer to have the weight on the rotor and keep
the thrust bearing as a guide.  However, I don't
stick it directly on the rotor.  Instead I use a
piece of 1/8" aluminium shim stock directly on top
of the rotor.
When I want to change the rotor, I simply loosen
the rotor clamps, pry out the shim stock and
voila! Thrust bearing supports antenna till the
rotor goes back in.

73 de Brian/K3KO
--------------------------------------------------------------------------------

Don't pin it. I always put all the weight on a HAM-M,
don't think I have ever used a thrust bearing in my
life. But, you have to have some way to jack up the
mast to get  rotor out.

Ed, W3EKT.

---------------------------------------------------------------------------------

Hello Jack,
As reported in prior posts, having some weight on the rotator is a good
thing, as they are designed for a vertical load, which helps keep their
bearings seated and wearing evenly. This also seems to help them resist
lateral loads from wind, which try to push the mast back-and-forth down
at
the rotator level. Just be sure you are not over-loading the rotator
weight-wise.
What I did was to install a second thrust bearing above the rotator.
During normal operation, I have the clamping bolts tight on the upper
thrust
bearing and loose on the lower bearing, with all the weight being taken
by
the rotator (I also have a Yaesu 800 SDX). For maintenance, I lift the
mast
and antenna assembly up just enough to clear the rotator, and tighten
the
clamp bolts on both bearings to hold it in place. Then I can remove the
rotator.

--...MARK_N1LO...--
--------------------------------------------------------------------------------

Thanks guys,  W3TMZ


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