[TowerTalk] HDX 555 Motor Drive Bearing

[Jim Thomson]

Date: Thu, 4 Jul 2019 16:08:18 -0500
From: Phil Snyder <n9lah at comcast.net>
To: towertalk at contesting.com
Subject: [TowerTalk] HDX 555 Motor Drive BEaring

<Hi All

<Went out this morning to crank up the tower to see if I could hear any 
<of the EU on 6 meters. as soon as it started up I heard a couple 
<cracking noises. I stopped and tweaked it up and down a little and 
<discovered that the flange bearing on the back side of the multi wrap 
<sheave failed.

<Anyone with experience replacing this? I was able to retract the tower 
<to a point that I can block both sections to the base. My thoughts are 
<to release the tension from the positive pull down end of the cable, 
<loosen and support the drive assembly so I can swing it out of the way 
<to get the bearing out. I am assuming I will need to take it to one of 
<the local bearing shops, unless some one knows what bearing to replace 
<it with. I know lots of stuff changed over the years at UST and I 
<purchased this used so don't know the age.

<N9LAH

##  are  u  talking  abt  the flange bearing on  each end of the  drum ? 
The shaft on my drum is  2 inch solid steel.... and  UST  used a 2 hole
flange type  bearing.   These are the type  that  allow for some  shaft  misalignment.
I  call  em...floating  type bearings.    One  of the mounting hole flanges had  cracked 
right through.  UST  shoulda used  a  3 or  4 hole mounting  bearing.   This  was the  bearing 
where the 6  inch chain sprocket is.    I had  a helluva  time  getting the  sprocket off.  The
key was jammed in  tight.   Bearing itself  was  stuck on  good.    Used a torch  plus gear  puller
to  get the  sprocket  off.   Got  the  bearing  half  off.   Ended  up cutting the bearing  apart  with
a zip wheel.  

##  New  key is longer...so  I can get at it to pull  out.    New  double wide sprocket is  better  designed.
Never  seize   on everything.   Right angle and also 65 deg  angle  zerk  fittings  installed everywhere.
Major  pita......  poor  design.  This is on an old style  HDX-  689. 

Jim   VE7RF