[TowerTalk] Thrust Bearing adjustment
jim.thom at telus.net
Thu Apr 10 19:40:58 EDT 2014
Date: Thu, 10 Apr 2014 13:46:43 -0700 (PDT)
From: Mike Fahmie <wa6zty at yahoo.com>
To: Tower Talk <towertalk at contesting.com>
Subject: [TowerTalk] Thrust Bearing adjustment
I'm about to raise a 72' US Tower equipped with a pair of TB2US thrust bearings spaced about 3'.? I'll be using a TailTwister2 Rotator.? Is there a procedure for centering these components to preclude binding?
I doubt there is a way to make the two bearings share the vertical load, so which one should I choose.? I'm thinking that the top bearing should take the load and use the lower bearing to stabilize the mast laterally.
## DON’T use the set screws in the 2nd ..lower TB2US. I use two of the same bearings on my UST-HDX-689. Lower bearing is 4 foot down from the top. PP rotor is 6 foot down from the very top. 2 foot between
lower bearing and rotor. The tb2us uses an eliptical locking ring. It will either lock CW..or CCW. Just make sure u know which way it went on. A small recessed partial hole on the locking collare is whacked with a drift punch..to lock the ring.
## so leave the bottom bearing loose....so it only takes the lateral load..that’s it. You can only ever line up 2 things...not 3. So with the 2 bearings + rotor.... it becomes the top bearing and rotor...never the middle
bearing. And I sure as hell would not rely on that top double plate and cylinder on the UST towers to take all the load...esp when rotor removed..mast elevated a bit...and only the top bearing used. Not with
a 20 ft mast.... with 14 ft above the tower..and 6 foot into the tower. Which becomes 15 ft above and 5 ft below..when rotor is removed. The double plate at the top of the tower and cylinder has a set screw..used to lock the mast when rotor is removed. I would supplement that with some temp u bolts on the mast + angle steel..so the mast doesn’t rotate in a high wind with rotor removed.
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