[TowerTalk] Which Thrust Bearing to Use

[charlie at thegallos.com]

> Looks really well made.  I had the original Rohn counterpart for years and
> it just kept on going.
> I added a zerk fitting so I could grease it.  They last a very long time
> dry without lube, but I am anal
> about lubing everything hihi.
>
>
> Bob
> K6UJ


Looks nice, but one thing I just have not been able to understand for years

Tower thrust bearings are a LOW rotation speed, high load application,
probably the WORST place to use ball bearings.  I would expect either
tapered roller bearings, or today, do what most of industry does, and use
an engineering plastic bearing.  I mean, we don't need a torlon bearing
there (the loads are NOT that high)

I mean, a glass reinforced nylon, or a PTFE (Teflon) (say a 25% glass
filled or molly filled) isn't going to cold flow at ALL under loads a 2"
mast could sustain, will NEVER need lubrication, will never corrode etc

You either get them molded for you (for some materials would be the
cheapest way - you do NOT want to know what torlon costs), or you slice it
from tube, or you even just use end on rods set around the circumference

I mean, today they run the pivot bearings and lower boom bearing on cranes
in plastic bearings, because they hold up better than metals in those low
rotation speed, intermittent rotation applications