McMaster Carr (www.mcmaster.com) has .025" x 6" x 12"
teflon-garolite sheets, but they are $42.00 each (ouch!!). They
also have .063" x 12" x 12" ultra-high molecular weight
polyethylene sheets (as suggested by W6RMK) for $2.94 each,
but the UV resistant variety is only seems to be available in 0.25"
thick sheets (probably not very flexible). They have a lot of
other materials available and a good search engine on their
website.
Seems like the metal shim stock (brass or aluminum) would be
an inexpensive and effective choice as well.
73 de Mike, W4EF.................................................
----- Original Message -----
From: "Michael Hatzakis, Jr" <mikehatzakis@yahoo.com>
To: <n8de@thepoint.net>; "Peter Sundberg" <sm2cew@telia.com>
Cc: <towertalk@contesting.com>; "Michael Tope" <W4EF@dellroy.com>
Sent: Tuesday, April 08, 2003 10:07 AM
Subject: Re: [TowerTalk] Above the Thrust Bearing
>
> I have the same issue with my MA-550 and the collar that hold the tube.
Any ieas on where one can find this kind of teflon? I think it's a great
idea. I saw a localham do something like this and it was very effective
> Don Havlicek <n8de@thepoint.net> wrote:Peter,
> In the ORIGINAL posting, the tower is Heights ALUMINUM.
> The 'guide tubing' at the top is SMOOTH aluminum tubing.
> He is NOT looking for a COLLAR, but something to keep the MAST from
> wearing against the COLLAR.
> My suggesting of Teflon sheet [PTFE] between these two still holds.
> Been there, DONE THAT with my Universal ALUMINUM towerS.
> Don
> N8DE
>
> Peter Sundberg wrote:
> >>From my experience it is not the rotation of the tube that does the
> > grinding, it is the constant movement caused by the wind that does it.
Even
> > a small gap between the two tubes will make it possible for the wind to
> > move things a little and after a few years the wear on the aluminium
tube
> > is clearly visible.
> >
> > Furthermore, thin PTFE sheet as is not a good choice as a "bushing", it
> > will easily be punctured if the inside of the galvanized tube is not
> > extremely smooth and normally it is not since the galvanizing process
that
> > makes the surface rather rough. PTFE is just too soft.
> >
> > 73/Peter SM2CEW
> >
> >
> >
> > At 05:56 2003-04-08 , you wrote:
> >
> >>A couple of stainless steel hose clamps (one placed above the pointy
> >>top tube and one below) and overlapping the top and bottom edges of the
> >>bearing sheet respectively will keep it (whatever the material
> >>chosen) in place.
> >>
> >>Of course, how many rotations of the antenna would it take to reduce
> >>the strength of the unprotected aluminum mast significantly (say to the
> >>90% level)? I am thinking that would be a serious rotator workout!
> >>
> >>73 de Mike, W4EF......................................
> >>
> >>----- Original Message -----
> >>From: "Don Havlicek"
> >>To: "Jim Lux"
> >>Cc: "(Reflector) TowerTalk"
> >>Sent: Monday, April 07, 2003 8:19 PM
> >>Subject: Re: [TowerTalk] Above the Thrust Bearing
> >>
> >>
> >>
> >>>Jim,
> >>>He wants something to fit INSIDE that collar.
> >>>UHMW sheet isn't flexible enough for that task.
> >>>The Teflon sheet [about 3-4 mil] will be perfect for his task, and
> >>>require NO machining.
> >>>Don
> >>>N8DE
> >>>
> >>>Jim Lux wrote:
> >>>
> >>>>Don't bother with Teflon... use High density (UHMW) polyethylene
cutting
> >>>>boards... Less than $10 at your local discount store.. Very good
> >>>
> >>dielectric
> >>
> >>>>properties, easy to cut (make sure that saw is SHARP), and almost as
low
> >>>
> >>a
> >>
> >>>>friction coefficient as PTFE.
> >>>>Unless you were planning to heat your antenna up hot enough where the
PE
> >>>>starts to flow....?
> >>>>
> >>>>----- Original Message -----
> >>>>From: "Don Havlicek"
> >>>>To: "Jerry K3BZ"
> >>>>Cc: "(Reflector) TowerTalk"
> >>>>Sent: Monday, April 07, 2003 6:17 PM
> >>>>Subject: Re: [TowerTalk] Above the Thrust Bearing
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>>Jerry,
> >>>>>Get some Teflon sheet and cut a piece to fit. Should last a lifetime.
> >>>>>Don
> >>>>>N8DE
> >>>>>
> >>>>>Jerry K3BZ wrote:
> >>>>>
> >>>>>
> >>>>>>I've received several good comments and ideas, thanks. What I'm
really
> >>>>>>concerned about is the aluminum mast and the aluminum tower sleeve
> >>>>>
> >>>>wearing
> >>>>
> >>>>
> >>>>>>away slowly from metal-to-metal contact. But grease isn't the only
way
> >>>>>
> >>>>to
> >>>>
> >>>>
> >>>>>>keep them from actually touching. What about some sort of "bushing"
to
> >>>>>
> >>>>fit
> >>>>
> >>>>
> >>>>>>between the mast and the sleeve?
> >>>>>>
> >>>>>>I was thinking of a section of thin-wall pvc of appropriate diameter
> >>>>>
> >>and
> >>
> >>>>>>wall thickness, sliced length-wise and inserted betwen the mast and
> >>>>>
> >>>>sleeve
> >>>>
> >>>>
> >>>>>>on opposite sides of the mast, then clamped to the mast above and
below
> >>>>>
> >>>>the
> >>>>
> >>>>
> >>>>>>sleeve. The idea would be for the pvc to be sacrificed and replaced
> >>>>>
> >>>>every
> >>>>
> >>>>
> >>>>>>few years as necessary. I'm no engineer and I don't even play one on
> >>>>>
> >>TV,
> >>
> >>>>so
> >>>>
> >>>>
> >>>>>>any comments from those more talented than I?
> >>>>>>Jerry K3BZ
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>_______________________________________________
> >>>>>>
> >>>>>>See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> >>>>>
> >>>>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> >>>
> >>any
> >>
> >>>>questions and ask for Sherman, W2FLA.
> >>>>
> >>>>
> >>>>>>_______________________________________________
> >>>>>>TowerTalk mailing list
> >>>>>>TowerTalk@contesting.com
> >>>>>>http://lists.contesting.com/mailman/listinfo/towertalk
> >>>>>>
> >>>>>
> >>>>>
> >>>>>_______________________________________________
> >>>>>
> >>>>>See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> >>>>
> >>>>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> >>>
> >>any
> >>
> >>>>questions and ask for Sherman, W2FLA.
> >>>>
> >>>>
> >>>>>_______________________________________________
> >>>>>TowerTalk mailing list
> >>>>>TowerTalk@contesting.com
> >>>>>http://lists.contesting.com/mailman/listinfo/towertalk
> >>>>
> >>>>
> >>>>
> >>>
> >>>_______________________________________________
> >>>
> >>>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> >>
> >>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> >>questions and ask for Sherman, W2FLA.
> >>
> >>>_______________________________________________
> >>>TowerTalk mailing list
> >>>TowerTalk@contesting.com
> >>>http://lists.contesting.com/mailman/listinfo/towertalk
> >>>
> >>
> >>
> >>
> >>_______________________________________________
> >>
> >>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> >
> > Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> > questions and ask for Sherman, W2FLA.
> >
> >>_______________________________________________
> >>TowerTalk mailing list
> >>TowerTalk@contesting.com
> >>http://lists.contesting.com/mailman/listinfo/towertalk
> >>
> >
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> Michael Hatzakis, Jr MD
> Physiatrist, Treating Individuals with Neuromuscular Disabilities
> Consultant, Information Technology Based Health Care Solutions
>
>
> ---------------------------------
> Do you Yahoo!?
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> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
|