I'd replace the pointy-top section with a flat-top one and use a 2" thrust
bearing. And also a 2" mast. Since you're in for thunderstorms and high
winds, work done in such conditions will be perfect, and will last forever!
But it does sound like you need to shim the mast-to-rotor interface to
center up the rotating mast better. That's normal. The HAM series rotors
only center the mast when the mast used is 2-1/6" diamenter, I believe, and
anything smaller O.D. will rotate out of centricity, causing precisely the
problem you have. The last pointy-top R25 section I owned (many years ago)
would not even pass a 2" mast, let alone allow one to rotate.
WB2WIK/6
"If everything seems under control, you're just not going fast enough." -
Mario Andretti
> -----Original Message-----
> From: Dale L Martin [SMTP:kg5u@hal-pc.org]
> Sent: Tuesday, December 03, 2002 9:36 AM
> To: TowerTalk Reflector
> Subject: [Towertalk] New Rotator In Place; Mast Now Binds
>
>
> Yesterday afternoon, I replaced my old HAM-M with a HAM-IV recently
> returned
> from getting serviced.
>
> The M was showing some signs of age and it has been some years since it
> was
> last overhauled.
>
> On checking out the rotation of the new rotator on the tower, it swung
> from
> North through East to South. When swinging back the other way, rotation
> stopped at East. I was finally able 'ooch' the rotator through to about
> NNE
> where it resumed normal rotation speed. (The rotator worked perfectly on
> the test bench, by the way.)
>
> I moved the rotator back to South through East then back up to East where
> it
> stopped. I went up the tower (Rohn 25G, pointy top) to check things out.
> It looked like the mast was against one side of the bottom of the pointy
> top
> mast guide. When I had installed the rotator, I left the rotator base
> mounting bolts loose. I then tightened them up AFTER tightening the mast
> clamp--from something I read on the TT reflector.
>
> With the rotator on East, the rotator portion of the mast clamp is on the
> West side of the rotator where the mast seems to be tight against the
> pointy
> top guide. Is shimming the mast in the clamp a workable solution for
> this?
>
> If I shim it such that the mast now clears the bottom of the guide by a
> little bit where it's now binding, will I just move the binding point or
> will there likely be enough clearance between the mast and the guide to
> rotate freely? I didn't measure it, but it looks like there's about a
> 3/16-1/4" of clearance on the other side of the mast from where it
> contacts
> the guide.
>
> Comments/Suggestions?
>
> Of course, today's weather forecast is thunderstorms, high winds, cooling
> temps.
>
> 73,
> dale, kg5u
>
>
>
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