FYI, there are similiar mounting bolt loosening problems with HDR-300
rotors. I also double nut the mounting bolts.
Bob, W2CNS@arrl.net
> -----Original Message-----
> From: owner-towertalk@contesting.com
> [mailto:owner-towertalk@contesting.com]On Behalf Of dan hearn
> Sent: Monday, March 22, 1999 9:18 PM
> To: K7LXC@aol.com
> Cc: towertalk@contesting.com
> Subject: Re: [TowerTalk] Orion rotator application note
>
>
>
> During a conversation w Mike a week ago he said that M2 abandoned
> the rubber
> donut shock absorber because the bolts loosened and gave trouble.
> He also said
> that rotator mounting bolt loosening is a frequent problem. They
> have supplied
> some commercial rotator systems w drilled head aircraft grade
> bolts safety wired.
> These are very expensive. He also said they are looking at some
> sort of sheet
> metal plate with bend up tabs as used on some automobile
> assemblies. He suggested
> using RTV on the bolt heads rather than Loctite. This can be cut
> away with a
> knife if removal is necessary. He feels that it is necessary to
> periodically do
> maintenance tightening of bolts.
> I wonder if the different thermal coefficients of aluminum and
> steel cause some
> of these problems. I like the use of lock washers to accomodate
> small dimensional
> changes w temperature. Double nutting, as suggested by Steve , is
> certainly a
> good practice. 73, Dan, N5AR
>
> K7LXC@aol.com wrote:
>
> > Greetings, TowerTalkians --
> >
> > Other than a prop pitch, the Orion 2800 is about the best amateur
> > rotator available but I've run across three Orions in the last couple of
> > months with the same problem. And that is, in spite of having
> the best and
> > beefiest mast clamp in the world, all three of them had
> loosened up and the
> > antennas were being turned by the wind. One was a TH11, one was
> a C-4XL and
> > the other was an M2 2L 75M yagi.
> >
> > In all cases, the nuts on the long bolts through the
> mast clamp had
> > loosened up. And all of these nuts were the nylock ones supplied by the
> > factory and also had spring lockwashers. These were both
> versions - the fine
> > threaded and the coarse threaded ones so they are both subject
> to the same
> > problem.
> >
> > While re-tightening them is great, I think it is
> inevitable that they'll
> > loosen up again. In the case of the 2L 75M, it went through
> almost 2 winters
> > before coming loose.
> >
> > Anyone using this rotator should plan on taking added
> precautions to
> > prevent this. In my cases, I'm going to double-nut everything.
> Another option
> > would be to use some Locktite (sorry - I can't remember if it's
> the blue or
> > red to use). Or do both. In any case, you won't be sorry.
> >
> > Cheers, Steve K7LXC
> > http://www.championradio.com
> >
> > --
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>
>
>
>
> --
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>
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