[TowerTalk] Frozen Rotor

Wed Jan 19 14:24:46 EST 2005

OK, Roger.  Well, I have never lived that far north, but the vinyl cone 
worked for about 10 years up in northern NJ until I moved here to SW 
VA.  If the vinyl is flexible enough at room temperature, it won't lose 
all of its flexibility at moderately low temperatures.  But if you're in 
the upper peninsula, all bets are off!  Don't you guys have doors on the 
second floor of your houses that open up into mid air until there's one 
of your typical snowfalls, when it's the only way to get out?

I don't doubt what you say about the grease, and I would prefer to use 
the cone.  However, I saw the grease trick suggested in some ham 
publication at one time or another and am trying it myself now. I 
mounted my antenna so close to the thrust bearing that I didn't leave 
enough room for the cone.  I was too lazy to raise the antenna foot or 
so after I had made all the connections and pinned the mast, so I 
thought I'd give the grease trick a shot.  We've had a fairly wet winter 
with some temps below zero and in the single digits, and the rotor 
hasn't frozen up yet.  Let's see what happens.

73, Joe

K8RI on Tower Talk wrote:

>
>
>
>> 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.
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>> _______________________________________________
>>
>> 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.
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
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