Hi Guys,
I 'm no PE, as you all should know by now, but I still have an opinion (as you
should all know by now).
Anyway, there are a couple of key pieces of information left out of the original
scenerio. Nothing is said about wind so we have to assume zero wind and
nothing is
said about the load being unbalanced on one side of the mast or the other so we
have
to assume balance. This being the case, I agree with Barry: there is no side
load
on the rotator in either case.
The model you have chosen to evaluate is too simplified and does not include
enough
data to allow a reasonable analysis.
Stan w7ni@teleport.com
Barry Kutner wrote:
> On 12 Sep 98,, K7LXC@aol.com <K7LXC@aol.com> wrote:
>
> >
> > In a message dated 98-09-12 10:37:12 EDT, n7ex@athenet.net writes:
> >
> > > Explain how you would calculate the side loads on the rotator in both
> > > cases
> > > below.
> > >
> > > First case: The weight of the mast supported by the thrust bearing,
> > >
> > > Second case: Weight of the mast supported entirely by the rotator, Assume
> > > the mast has minimal (few thousandths) of play where it goes through
> > > the
> > > top of the tower.
> > >
> > The mast is the lever arm and the pivot point is where it contacts the
> > top of the tower. The mast and antenna load is trying to pry the bottom of
> > the
> > mast that's attaced to the rotator in the opposite direction with LOTS of
> > side
> > force.
> >
> > Cheers, Steve K7LXC
>
> PEs out there, correct me if I'm wrong...
> It seems to me the vertical load on the rotor, as in case 1 and 2
> above, has no effect on the side load forces (cosine of 90 = 0),
> assuming the thrust bearing is the pivot point of the system.
> 73 Barry
> --
> Barry Kutner, W2UP Internet: w2up@mindspring.com
> Newtown, PA FRC alternate: barry@w2up.wells.com
>
> --
> FAQ on WWW: http://www.contesting.com/towertalkfaq.html
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
--
66'9k'?:'<@'7:'h;'jj'7:'8m'=;':h'j@'@7'?i'=9'm<'jh
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|