[TowerTalk] Which Rohn thrust bearing to use

[Grant Saviers]

The DXE thrust bearing looks like a well thought out design. See the 
cross section picture.   Good WX protection.  Fairly robust casting 
sections (my TB3 split).  The ball races are 45 degree angular contact 
which makes the bearing equally capable in thrust and radial loads.  
That is not so in the TB series IIRC.  The DXE Summit Racing MechEng 
heritage shows.

The only thing I would like to see added are a couple of opposing grease 
fittings (and a 3" mast version).  For most greases, the oil evaporates 
after 5 years and just leaves the carrier.   DXE might/should use a 
fully synthetic grease with anti-fretting additives which will last 
longer but not as long as many tower bearings are left in service.

Grant KZ1W

On 12/6/2016 5:44 AM, Jim Thomson wrote:
> Date: Mon, 5 Dec 2016 15:56:27 -0500
> From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk at tm.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Which Rohn thrust bearing to use
>
> The Fafnir and many others including imports are far better than the TB3
> and 4.
>
> 73
>
> Roger (K8RI)
>
> ### Anything is better than a TB3 or TB4.   UST uses PEER brand
> thrust bearings for both the big drum, and the mast.  The ones used on the
> mast are NOT designed to self align.   The thrust bearings on the big
> drum ARE designed to self align.  They come with a locking collar, that
> has a couple of holes, spaced 180 deg apart, on the top portion of the
> locking collar.  Just rotate the locking collar CW a bit and it binds tight, then
> use a drift punch  in one of the 2 x holes, and give it a gentle smack. Then
> the locking collar wont budge.  Locking collar also comes with a set screw.
> Replace it with a SS type, then slop some never seize onto the threads of both
> the SS set screw and also the threads of the collar.
>
> ##  The TB3 /4 although popular, are not cost effective, not for what you are
> getting.
>
> Jim   VE7RF
>
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