[TowerTalk] Which Thrust Bearing to Use

[Jim Thomson]

Date: Fri, 9 Dec 2016 11:55:51 -0500
From: "john at kk9a.com" <john at kk9a.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Which Thrust Bearing to Use

I have much less mast inside the tower but I concur that there is no
reason to have three bearings on the mast (two thrust plus the rotator).

John KK9A

##  I have always used 2 thrust bearings... + the rotor. But I made sure the
middle thrust bearing was adjustable..so I could do a precise alignment.  These days,
In actual usage, the 3 x set screws are backed off, or removed.  So zero binding, but if the
wind gets up, the middle bearing will take some of the load. 

## IF the rotor has to come out, then a temp M2  mast clamp...used on their OR-2800 rotor,
sits on top of each bearing, so the mast doesnt budge.  The 2 x bearings take all the weight.  
Mast stays put, dead vertical. 

##  6 ft of mast inside the tower. Bottom bearing is 2 foot above the rotor.  PP hangs below
the rotor plate. 

## With 6 ft into the tower and 14 ft above the tower, that is a helluva lot of weight above
the top of the tower.   Even with the UST double top plate and collar assy, I still would not trust
it.   So in went bearing number 2. 

Jim  VE7RF