[TowerTalk] Re: Thrust Bearing Usage

[Doug Renwick]

Here we go again...making assumptions.  When you are using an
undersized thrust bearing I can see your point Kelly.  Not
everyone is using a CDE (MFJ) Ham or Tailtwister rotor.
Have you ever seen the bearing inside a HDR-300 rotor?
It is dinky and I feel not designed to take a lot of weight...so
the thrust bearing takes most if not all the weight.  Different
rotor/mast/antenna combinations require different designs.
BTW I place a saddle clamp on top of the thrust bearing for
safety purposes just in case I have a senior's moment.

Doug

ve4xt at mts.net wrote:

> As much as it pains me to see this thread revived so 
> quickly after it died out the last time (this is well covered 
> in the archives)...
> 
> I'm in the bear-the-weight-on-the-rotator camp.
> 
> As one has suggested, many bearings have screws 
> designed only to centre the mast. Also, as far as even 
> the HyGain CD45II is concerned, there are more 
> bearings on more races in rotators than in typical thrust 
> bearings.
> 
> If this makes rotator failure more frequent, so be it. 
> Think about it: if I have to change out the rotator, that's a 
> fairly simple procedure, even on one that's bearing 
> weight. If I have to change out the thrust bearing, I have 
> to make one end of the mast pass through the thrust 
> bearing.  I'd rather lift the antenna-mast assembly the 
> 1/8-inch or so it will take to remove the weight from the 
> rotator than the two feet or more it will take to have the 
> lower end of the mast come out of the tower... From that 
> standpoint, I'd want to make sure the thrust bearing 
> lasts as long as possible. No matter how you cut it, 
> replacing a thrust bearing is a big job, perhaps even 
> mandating lowering all the antennas to the ground.
> 
> 73, kelly
> ve4xt


-- 
Doug Renwick VA5DX
PO Box 50, Clavet, Saskatchewan, Canada S0K 0Y0
VE5RA at sasktel.net
First VE5 9BDXCC
What profit it a ham if he gains all the awards yet forfeits his soul?
I'll run the race and I will never be the same again.