[TowerTalk] refurbish a Thrust bearing ?

[Jim White, K4OJ]

I sorry guys to reopen this can of worms.   But why do they call it a
THRUST
bearing???

It is used to take most of (40-60%) of the weight off of the rotor.   Yes
the
rotor is designed to handle it, but that does not mean that it wont last
longer
without it.

How can it take part of the weight????????  Either it bears the weight or
it does not.....



It also allows you to use a longer mast pole and support it at both ends.
Sorta of like a axel shaft on a car.

Don't car axles have slip joints which allow for length +/- situations??? 
A mast does not....I have often thought about using something along these
lines where a splined shaft and mirror matching internally splined tube are
in the rotating mast line.  By doing this you COULD bolt down the mast and
take its load as far as dead weight off of the rotor to be born by a
bearing.  Other wise there is no way you can tell me that there is a ham
who can make sure the mast is perfectly vertical and as such no way a ham
can ensure there isn't up/down movement of the mast pipe as the antenna
rotates.



Take a15 foot  pole and hold it in your hands and spread your hands apart 5
feet and let someone grap the end.   Then do the same with your hands 1
foot
apart.   I think that you can feel the change.


Agreed......BUT......this I do not feel is the heart of this thread....I
(and I gather a lot of others on this reflector) feel that the use of the
thrust bearing is best as an aide in limiting the lateral forces on the
rotor, not the downward forces.



Granted, I am not a P.E. 

Me., neither and I have erred on this reflector before...and learned from
respondents to it.


But I have been climbing and installing towers for a
long time.

Me too....since before I was licensed (slave labor to Ham parents, you
know!)




I cannot give you the dynamic equations of why it is better, I
just know WHAT WORKS from experance.

I agree with you that what works is what is best, and we ar e not rocket
scientists in ham radio (well mebbe a few of us are)...but I suspect you
may have been hurting your rotors all along by have up and down forces put
on the rotor as it rotates due to the mast being vertically pinned above
the rotor in a bearing since the mast was not vertical and as such has an
up and down component as it rotates.


No Nomex Clothing 

any longer - easy on the flames!

73,

Jim, K4OJ
k4oj@ij.net

Only 2 months until Sweepstakes CW, make sure you work me so you will not
miss the elusive South Floirda multiplier!


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