[TowerTalk] Inexpensive thrust bearing?

Wed Mar 21 18:25:23 EST 2007

Thanks Jim, Gale, et. al.,

I will have the prop pitch mounted down in the tower about ten feet.
The mast will thread through a bearing about ten feet above it that will
hold side to side force.  I was just concerned with the weight on the
prop pitch.

Again, thanks!

Rob, KL7NA

On Wed, 2007-03-21 at 15:41 -0500, Jim Miller wrote:
> The side to side "thrust" has been addressed.  If you want it to carry the
> weight of the antenna system (or part of it), I always wondered about using
> a throughout bearing like are used on manual clutches in autos or trucks.
> These are made for high speed, high temperature, and very high forces.  They
> are not waterproof and would have to be protected somehow and could handle
> some side to side but could be used with one of the many suggested methods
> of solving the side to side forces.
> 
> 73, Jim
> 
> ----- Original Message ----- 
> From: "Rob Frohne" <frohro at wwc.edu>
> To: "towertalk" <towertalk at contesting.com>
> Cc: "K8RI" <K8RI-on-TowerTalk at tm.net>
> Sent: Wednesday, March 21, 2007 3:22 PM
> Subject: Re: [TowerTalk] Inexpensive thrust bearing?
> 
> 
> > Thanks everyone for the ideas on thrust bearings.
> >
> > They have been very helpful.
> >
> > 73,
> >
> > Rob, KL7NA
> >
> > On Wed, 2007-03-21 at 14:23 -0500, mryan001 wrote:
> > > Oh,oh...I feel a "..we're going to beat this subject to death..." coming
> on.
> > > Anyone want to talk about seabirds again instead?  - Mike
> > >
> > > -----Original Message-----
> > > From: towertalk-bounces at contesting.com
> > > [mailto:towertalk-bounces at contesting.com]On Behalf Of K8RI
> > > Sent: Wednesday, March 21, 2007 2:08 PM
> > > To: towertalk at contesting.com
> > > Subject: Re: [TowerTalk] Inexpensive thrust bearing?
> > >
> > >
> > > You can build a thrust bearing for pennies or maybe a few dollars that
> is
> > > far superior to most commercial thrust bearings particularly if it is
> used
> > > to keep the mast centered and does not serve as a support which they
> > > shouldn't in most cases.
> > >
> > > I'm getting rid of my ROHN thrust bearings (lot more than $50) and
> replacing
> > > them with a piece of pipe about 18" long,  albeit the finished product
> will
> > > be a bit more elaborate than most think of when a piece of pipe is
> > > mentioned.  As far as binding, or freezing you simply get a sheet of
> > > silicone rubber long enough to go around the mast and pipe at least one
> and
> > > a half times. I prefer a bit over two times.wrap it around the mast so
> it
> > > extends down over the pipe by at least 3 or 4 inches. Use a SS hose
> clamp to
> > > hold it in place on the mast.  If need be a bit of Lithium grease can be
> > > added where it slides on the pipe/thrust bearing.
> > >
> > > The wood bearing or "Amateur Block" when constructed properly also has
> the
> > > advantage of being adjustable. For that I'd use oil impregnated hard
> wood.
> > >
> > > > You get what you pay for.  An inexpensive (aka cheap) thrust bearing
> or
> > > > substitute device (not recommended) may in the long run cost you more
> in
> > >
> > > It depends on how elaborate you want to get, but from what I've seen,
> most
> > > inexpensive thrust bearings are more reliable and serve the function of
> a
> > > thrust bearing better than the commercial ones.
> > >
> > > > time and frustration than if you spent the $50 in the first place.  A
> > > > cheap
> > > > bearing that freezes up, rusts out, binds, etc especially in the
> middle of
> > > > winter when tower climbing, mast and antenna pulling, etc. is
> impossible
> > > > or
> > >
> > > It only takes a little thought to prevent these things from happening.
> > >
> > > > unsafe can make the money you should have spent to do it right in the
> > > > first
> > > > place not seem excessive.
> > > > Jerry
> > > > N7WR
> > >
> > > Roger Halstead (K8RI and ARRL 40 year Life Member)
> > > N833R - World's oldest Debonair CD-2
> > > www.rogerhalstead.com (Use return address from home page)
> > >
> > > >
> > > >
> > > >>From: Rob Frohne <frohro at wwc.edu>
> > > >>Reply-To: frohro at wwc.edu
> > > >>To: towertalk at contesting.com
> > > >>Subject: [TowerTalk] Inexpensive thrust bearing?
> > > >>Date: Wed, 21 Mar 2007 10:06:59 -0700
> > > >>
> > > >>Hi Everyone,
> > > >>
> > > >>Does anyone have a source for an inexpensive thrust bearing?  I have a
> > > >>plate on the top of my tower with a hole through it, and was thinking
> of
> > > >>putting a thrust bearing on, but the ones I found were around $50
> which
> > > >>for my frugal self is a bit spendy for a thrust bearing.  It seems
> that
> > > >>there is probably a cheaper way to do this with some kind of
> automobile
> > > >>bearing or a sleeve of pipe and some set screws, etc.  Does anyone
> have
> > > >>any advice?
> > > >>
> > > >>73,
> > > >>
> > > >>Rob, KL7NA
> > > >>--
> > > >>Rob Frohne, Ph.D., P.E.
> > > >>E.F. Cross School of Engineering
> > > >>Walla Walla College
> > > >>100 SW 4th Street
> > > >>College Place, WA 99324
> > > >>(509) 527-2075
> > > >>http://www.wwc.edu/~frohro/
> > > >>
> > > >>_______________________________________________
> > > >>
> > > >>
> > > >>
> > > >>_______________________________________________
> > > >>TowerTalk mailing list
> > > >>TowerTalk at contesting.com
> > > >>http://lists.contesting.com/mailman/listinfo/towertalk
> > > >
> > > >
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> > -- 
> > Rob Frohne, Ph.D., P.E.
> > E.F. Cross School of Engineering
> > Walla Walla College
> > 100 SW 4th Street
> > College Place, WA 99324
> > (509) 527-2075
> > http://www.wwc.edu/~frohro/
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
> 
-- 
Rob Frohne, Ph.D., P.E.
E.F. Cross School of Engineering
Walla Walla College
100 SW 4th Street
College Place, WA 99324
(509) 527-2075
http://www.wwc.edu/~frohro/