[TowerTalk] FW: Thrust Bearing - again!

[Jim Thomson]

Date: Tue, 18 May 2010 16:53:47 -0400
From: "Tommy Alderman" <aldermant at windstream.net>
Subject: [TowerTalk] FW: Thrust Bearing - again!


A more accurate URL to this bearing, below, is
http://www.peerbearing.com/pdf/MUD/2-Bolt%20Flanges.pdf


## Now these are the real deal.. and make the TB-3/4  look like sick puppies.

These are very similar to what Us tower uses.  The eccentric locking collar used
on the US tower corp bearings is also used in some of the models made by Peer.

## steve mentioned abt the set screw on the US tower corp bearings seizing up. 

I checked both of my used ones.. and the 7/16"  [fine thread]  set screw  on each
of them turns just fine.  Both set screws [ one per bearing]   were slopped with
lithium grease... black stuff.      They could easily be replaced by a  7/16" 
stainless steel fine thread  hex head bolt. 

Both of mine turn real smoothly. Each bearing has that grease nipple fitting.. so 
just squirt some lithium grease into it once or twice a year. 

Both my Rohm  TB-4  bearings  turn really rough.   The top section of tower they are mounted
in.. has been laying on the grnd... horizontal  for a few yrs now.  They were both brand new.  
new ones had  hammer whacks [ with a small scribe /punch]  on the set screw... to lock it into place.
[done by the factory].
Apparently if the set screw on the rohn bearings is in too far, balls get hung up.    If screw is out too far
then balls will get diverted into the side hole whear the setscrew is... and  again, balls back up behind the
diverted balls.. and it hangs up. 

Trylon sells  both the tb3/tb4... and the price is wicked for a TB-4   $200.00   [ canadian] .  On both my tb-4's
the 3 x transverse lock bolts  to center a mast  are rusted badly.. replaced em with SS  hardware... including nuts
etc, all of it.   Bottom line is.. it's not a real bearing.  

Back in the mid 80's... I made a couple of HB bearings  using new  taprered wheel bearings... [ like used on a  dump truck
or semi]    They looked just like  what roger shows inside his protistel rotor.    again... they are designed to be used
as wheel  bearings.. and mounted horizontal.   My neighbour  at the time was a machinist at alcan.. and machined
these beautiful  solid bronze  one piece flanges and inside tube.... all  from a solid block of bronze.... [all done on night
shift at 3 am] .   the bearing was a press  fit over the top of the thickwall hollow  bronze tube... and with a huge wide flange on top.
these were very nice.. but obviously cost prohibitive.  the wheel bearing.. and mating cup had to be packed with grease. 
Mating cup was welded to top plate of tower.   Very difficult to keep  moisture out of it.   Then bye bye wheel bearing. 

array solutions  use's  some kind of black composite plastic material.. 1"  thick.. with a 2" hole in it.. for the bearing.. on their
swinging gate .    You can see pix of it in their user manual.      http://www.arraysolutions.com/Products/sidemountusersguide1.htm   

Later... Jim   VE7RF
 

Tom - W4BQF