[TowerTalk] Frozen Rotor

[K8RI on Tower Talk]

> I've done something similar to what Larry has done; however, I use heavy 
> duty, flexible vinyl and fold it into a simple cone.  I wrap the top of 
> the cone around the mast above the thrust bearing so it forms an umbrella 
> to protect moisture from settling on or into the bearing.  The vinyl can 
> obtained as scrap from fabric shops or upholstery shops.

The problem with vinyl up here in the frozen north is it getting brittle.

>
> Another trick, although the mechanical purists might not approve, is to 
> pump grease into the thrust bearing until it comes out of the housing.

The problem with grease and a sleeve is although water does not disolve into 
the grease it can get mixed in with he grease. I've seen grease with so much 
frozen water mixed in it reminded me of a very dirty snow cone.  The sleeve 
at the top of a tower particularly lends itself to collecting water that 
will run down the mast to mix with the grease.

Most grease also thickens as it gets colder and some of the old standards 
that work well in summer are almost solid when the temperature hits single 
digits let alone minus digits..

There are greases made for high pressure and low RPM(surface movement) that 
will work well.
You don't need the high pressure part, but just consider it a bonus.

Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com
> Make sure it is distributed all around the contact surface between mast 
> and bearing.  The grease is incompatible with water and keeps ice from 
> getting in between the mast/bearing surfaces.  Messy, but works.



>
> 73, Joe
>
> W1GOR wrote:
>
>> Martin,
>>
>> I've had similar problems with the mast freezing in the sleeve...  My 
>> solution was to make a cone-shaped guard and fasten it around the mast 
>> slightly above the sleeve opening (seal it well).   It can be of 
>> sheet-metal although I used fairly stiff plastic sheet and heated it to 
>> form the cone. When done properly, any moisture (rain, snow, sleet) will 
>> be diverted away from the mast-sleeve junction and the mast will not 
>> freeze in the sleeve. You might want to apply some low temperature 
>> silicone grease to the mast, where it passes through the sleeve.  Don't 
>> use ordinary grease because it is not capable of withstanding very low 
>> temperatures without getting stiff. If you have enough space between the 
>> mast and sleeve, a sheet of TEFLON can be used in place of the silicone 
>> grease.   According to DuPont, TEFLON is the slipperiest material on 
>> Earth...<grin>   By the way, if you can find a GIANT FUNNEL, you will 
>> have most of the shield right from the start...!
>>
>> 73, Larry - W1GOR
>>
>> There are 10
>> types of people
>> in the world;
>>
>> Those that
>> understand
>> B I N A R Y
>> and those
>> that don't.
>>
>>
>>
>> ----- Original Message ----- From: "Martin AA6E" <msembx-aa6e at yahoo.com>
>> To: <towertalk at contesting.com>
>> Sent: Wednesday, January 19, 2005 11:54 AM
>> Subject: [TowerTalk] Frozen Rotor
>>
>>
>>> Winter greetings!
>>>
>>> With the help of a good antenna guy, I installed a roof-mount tower (20
>>> ft Rohn 25) with a Yaesu G-1000 holding up a 3-el SteppIR on an 8 ft
>>> mast.  Nothing exotic here, but it gets out nicely.
>>>
>>> We've had a couple of nights this winter of below 10F.  I've found the
>>> rotor just won't budge until morning, when things warm up into the
>>> teens.  What's going on?
>>>
>>> There could be some ice in the tower sleeve.  Is that the most likely?
>>> Shouldn't the G-1000 be able to break through?  The rotor does not slip
>>> against the mast.  (Indicator does not move.)
>>>
>>> What do people do to prevent this?  Lubricate the sleeve, provide a
>>> weather shield, heating tape, ...?
>>>
>>> 73, Martin AA6E
>>
>>
>> _______________________________________________
>>
>> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>> any questions and ask for Sherman, W2FLA.
>>
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>>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
> any questions and ask for Sherman, W2FLA.
>
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>