[TowerTalk] TowerTalk Digest, Vol 30, Issue 31

[G3rzp@aol.com]

VE6JY  said:
>Many rotator motors are now DC.
>
>And the current method  is fine as long as you have not yet installed the
>antenna (or no wind if  you have).




Shows how out of date I am. Yes, I was tacitly assuming that the  antenna 
wasn't yet installed.
 
Gary said:
 
>A true thrust bearing has a tapered bearing like that of the front  wheel 
>bearings on a car. Or it has sizable top and bottom plates if it  is ball 
>bearing. A bearing that is designed for a horizontal shaft is  not a 
>thrust bearing just because you mount it in the vertical  position.
 
Very true, and I suppose ideally, the tapered bearing would use trapezoidal  
rollers rather than balls. Although there are pre-loaded ball thrust races  
used in lathe headstocks. Fortunately, the speeds used in antenna rotators are  
not as high as in most other applications, so forced lubrication  and so  on 
isn't necessary. I don't know how much trouble someone in Ca or Az or Tx  etc 
would have with grease melting and running out. Not much of a problem in G  
land!
 
73
 
Peter G3RZP