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Re: [TowerTalk] OR-2800DC questions

Subject: Re: [TowerTalk] OR-2800DC questions
From: Jay Kesterson K0GU <>
Date: Wed, 30 May 2012 14:24:14 -0700
List-post: <">>
On 5/30/2012 1:52 PM, K8RI wrote:
> On 5/30/2012 4:33 PM, Jay Kesterson K0GU wrote:
>> Hi all,
>>      Need some advice on an OR-2800DC that is about 12 years old. Over the
>> years apparently the soft metal welded to the top plate, that attaches
>> it to the hard steel output shaft, wallowed out creating a lot of play.
>> This apparently caused the 1/4" guide bolt to unscrew and damaged the
>> inside of the rotator. I replaced the top plate and that got rid of a
>> lot of play. But I just opened to rotator to find a mess.
> I'm not familiar with this specific rotator, but "in general" I'd be
> very concerned why the above happened.  Possibly there was an antenna
> mounted "on the rotator" rather than on a mast through a thrust bearing?

   No the rotor was inside the tower, had a thrust bearing at the top 
and there was very little mast above the tower. It rotated a H-Frame 
with four 7el 6m yagis (~20 sq ft) for 10 years. Not a huge amount of 
wind load but a fair amount of torque when the frequent CO winds blow.

>>      The big gear on the output shaft has lowered down somewhat into the
>> rotator. The limit switch pin on the gear has dug into the torque plate:
> What normally holds the large gear in the proper position.  I assume
> it's not the pin sticking out the bottom that operates the limit switch
> lever.  Due to the long drive gear it appears the position of the large
> gear is not important or precise, but it should not ride on other parts
> that are not designed to support it.

   There is a 1/4 inch bolt that screws into the top of the shaft. 
Perhaps all that is really wrong is the bolt unscrewed itself and the 
shaft/gear dropped. But I would like to verify the measurements just in 
case. However the more I think about it after your comments it's likely 
the only problem is the bolt worked loose because of the slop in the top 
plate. I bought a new top plate so I will just clean everything up and 
put it back together. Guess I just needed to think out loud with someone 
else. :-) At least I hope so.


73,  Jay  K0GU


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