[TowerTalk] Fw: Rohn 45 Question

[Ian White GM3SEK]

Mark Robinson wrote:
>From: "Blake M" <n4gi at tampabay.rr.com>
>To: <towertalk at 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