Towertalk
[Top] [All Lists]

Re: [TowerTalk] Rohn TB4 Thrust bearing

Subject: Re: [TowerTalk] Rohn TB4 Thrust bearing
From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
Date: Tue, 06 Jan 2009 18:45:51 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>

K7LXC@aol.com wrote:
>  
> In a message dated 1/6/2009 2:00:29 P.M. Pacific Standard Time,  
> towertalk-request@contesting.com writes:
>
>   
>>   At one time 
>>     
> they said to run them dry, but I don't  find any recent mention of that.  
> There was a thread on this topic  last fall that was both pro and con for 
> greasing.
>  
>     There is no con. The 'con' position' was  previously stated such that 
> since they couldn't find that the manufacturer  didn't say not to grease was 
> that 
> it was okay to. The LXC Prime Directive  states to "DO what the manufacturer 
> says" and the usually unstated second part  of that is to "NOT do what they 
> don't tell you". If they say to do it - do it.  If they don't say to do it - 
> don't do it. 
>  
>   
But there were both pro and con *opinions* in the thread
I happen to agree with you in running the bearings dry.
>     You don't grease them. It just attracts particles  and junk out of the 
> air and promotes premature wear. It spins at 1 RPM - it  doesn't need to be 
> greased. 
>   
Agreed.
OTOH I've completely destroyed two TB-3s so far.  When I redo the top 
I'm going to build a sleeve be it one or two feet long.  I'd prefer to 
use roller bearings, but that'd mean some lathe time and building in 
some seals to keep out the weather.Plus it doesn't need to be that 
precise anyway.   2" double lip seals are relatively easy to find and 
not at all expensive. BUT a simple rubber cone made from sheet wrapped 
and clamped to the mast is more effective and has no low spots to 
collect water.  The sleeve OTOH is not precision.  Plastic or rubber 
devices/sleeves can easily be made to weather proof them and  a simple 
grease zerk at the top and bottom takes care of the lube. That and the 
sleeve doesn't add a support surface that may increase the loading on 
the rotator, or worse, give it negative loading with temperature 
changes. IOW it serves as side support only. Also with the sleeve, minor 
rust is not a problem except for appearance.  I can add a support block 
a few feet above the rotator to hold the mast when working "up there"  
What I need is to find about 2' of 2.5" OD DOM for the tube as it needs 
to be a nice fit over 2" OD tube.

73

Roger (K8RI)
>  
> Cheers,
> Steve    K7LXC
> TOWER TECH -
> Professional tower services for hams
> Cell: 206-890-4188
>
>
>
>  
_______________________________________________



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

<Prev in Thread] Current Thread [Next in Thread>