----- Original Message -----
From: "Ian White GM3SEK" <gm3sek@ifwtech.co.uk>
To: <towertalk@contesting.com>
Sent: Sunday, August 26, 2007 4:12 PM
Subject: Re: [TowerTalk] Fw: Rohn 45 Question
> Mark Robinson wrote:
>>From: "Blake M" <n4gi@tampabay.rr.com>
>>To: <towertalk@contesting.com>
>>Sent: Sunday, 26 August, 2007 1:35 PM
>>Subject: Re: [TowerTalk] Fw: Rohn 45 Question
>>
>>
>>> The bottom bolts on a Ham IV I had would work loose every few months
>>> when
>>> I
>>> had no load on it (I bought into the thrustbearing-takes-the-weight
>>> thing
>>> when I was new...). After I placed the full load of antennas and mast
>>> on
>>> it, this problem stopped.
>>>
>>> Rotors have HUNDREDS of bearings in them. Most thrust bearings I've
>>> seen
>>> only have 10-20.... I'm no expert in physics, but where to put all the
>>> weight seems like an easy decision to me.
>
>>Maybe a flat washer and a spring washer would stop the bottom bolts
>>coming loose. Blue loctite will certainly stop them coming loose.
>>
> Blue Loctite is excellent for many antenna jobs. It lubricates as you
> tighten the threads (prevents galling of stainless steel), locks the
> threads together so they won't vibrate loose, and seals them against
> corrosion... yet you can still unscrew the fastenings for maintenance.
> Clever stuff.
>
> However, threadlock is only a special type of glue, so it won't work if
> the threads in the rotor casting are loose or corroded. The answer then
> is to re-thread the holes to a larger size, and use *red* Loctite (the
> permanent locking grade) to fix lengths of stainless steel studding into
> the casting. The two parts of the rotor can then be held together by
> nyloc nuts, on the underside where they're easy to work on.
>
> 73 from Ian GM3SEK
> http://www.ifwtech.co.uk/g3sek
When there is insufficient meat to drill oversize, even to a metric size,
then JB Weld or a similar hard epoxy can be used to fill the hole. Then
drill and tap to the original size. Ive done this with success to the base
of the RC5A-3 as well to the top bell of several HAM-M size rotators.
Carl
KM1H
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