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[Towertalk] New Rotator In Place; Mast Now Binds

To: <towertalk@contesting.com>
Subject: [Towertalk] New Rotator In Place; Mast Now Binds
From: kg5u@hal-pc.org (Dale L Martin)
Date: Sun, 8 Dec 2002 15:16:39 -0600
Hi, Stan.

> It sounds to me like shimming the mast is exactly what you need to do.
> HamM, II's. III's, and IV's are made to take 2 1/16th OD masts.  I assume
> you are using a 2" mast, which means you need to shim it 1/32 of
> an inch to
> get it centered in the rotator.  Incidentally, you only need to
> shim the two
> areas right where the mast contacts the cast portion of the bell housing.
> There is no need to shim it where the mast contacts the moveable
> steel plate
> that goes next to the ubolt nuts and lock washers.
>

Understand.  I just got off the tower an hour ago after putting in two
shims.  It's still binding and grinding to a stop just north of east coming
from south -- interestingly enough, the rotator just cruises right through
NW-N-NE-E-SE to South.  But the other way, it just stops 10deg north of
East.  I can ooch above NE after a while to where it will rotate normally.

My mast is a measley 1.875" (I don't think I ever measured it before).  The
pointy tube measured 2.25" OD and I'm guessing the ID is about 2.125" or
something--couldn't get the calipers in there to get a good measurement.

Anyway, it looks like I need another 3/32" -- I put in two pieces of shim
material, each 3/64" thick.  Two more should do the trick.

Weather is closing in, so I'm going to have to hold off doing anything more
until at least Tuesday or Wednesday if the weather guys are on the ball with
their predicts.  It's going to be a race to the contest start time again....

> Remember to tighten the rotator mounting hardware in this specific order:
> (1)  Rotator ubolts first, to make sure the rotator rotation
> center line is
> exactly parallel to the mast rotation center line.  (2)  Rotator
> to rotator
> mount plate bolts second, to make sure the rotator mounting plate is flush
> and parallel with the flat bottom of the rotator.  (3)  Rotator mounting
> plate to tower leg ubolts last to make sure that you will not mount the
> plate such that it forces the rotator to be out line with the mast.
>

Yup.  Did that in that order.  In fact, didn't I buy a new plate and u-bolts
from you a couple of years ago? :-)  The plate is still in the garage, but
the bolts are up on the old plate. :-)


73,
dale, kg5u


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