[TowerTalk] Slow/Stuck rotator in one direction

john at kk9a.com john at kk9a.com
Tue Apr 17 20:07:33 EDT 2018

Jim has a good point. A long time ago I had a couple of these bearings, in
fact I still probably have them laying around somewhere. If I recall the
collar just kept the mast from dropping down and the bearing is sealed with
a grease fitting. I am not sure where dirt would go or how the collar could
would hinder rotation unless it cause binding by not lining up with the
rotator. I typically tightened the rotator mast clamp after the collar was
holding the weight of the antennas.

John KK9A

>From Jim Thomson VE7RF 

From: Dana Roode K6NR <dana.roode at gmail.com>
To: reflector Towertalk <towertalk at contesting.com>
Subject: Re: [TowerTalk] Slow/Stuck rotator in one direction

<Hi all,

<Thanks to everyone who responded to my email below.  I have resolved the
problem, which, long story short, was the thrust bearing.  The bearing on
the TX-455 has a "Eccentric Locking Collar".  When I got up on the tower
and looked at the bearing it was very dirty.  I loosened the allen screw,
freed the collar with a punch, raised the collar out of the way and tried
the rotator again.  It worked perfectly.  I cleaned it out best I could
with a degreaser, added new grease, and put the collar back down and it all
works fine now.

I was sure how to put the collar back in place; what I read online is that
you use a punch in the direction "the shaft rotates" - which is both ways
in the case of a mast but figured it would be opposite of the way I got it
off.  I wasn't sure how the collar fit downward on the bearing but think I
got it right.  Couldn't hammer the punch like I read since the bearing
turns.  Snugged it up and tightened the allen screw and it seems OK, but
must be a clearer instruction out there for these collars somewhere.


##  I have a UST  HDX-689... which uses  a pair of those  peer brand
thrust bearings +  mating eccentric  locking collars.  One is at top of
and the 2nd one is down  4 feet  into the tower.
Rotor is 6 ft  down from the top of tower.    I can easily hammer
the locking collar..in either  direction..with a small drift punch. 
The collar locks in either direction, but the bearing does NOT turn  with
IE: bearing will turn freely, regardless of whether the locking collar is 
locked cw, or  ccw, or not locked at all, and is between those two

##  You may have the locking collar  installed   incorrectly.   On second
the mast cant  rotate  anyway, since its  captivated by the rotor.   Both my
came with grease nipples.  Just pump correct grease into em, until  a bit of
the old
grease oozes  out the sides / top of the bearing.  You can also replace the
grease fitting
with fittings that have a 45 -65-90  deg angle, if that makes it easier to
get the grease gun in there.
I would put some never seize on those allen screws, or replace em with hex
head types, or  SS 
hex head types,..and still coat em with never seize.  Then you will have
less hassle to get them loose,
if  required.     

Jim  VE7RF

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