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" <n8de@thepoint.net>
>>To: "Jim Lux" <jimlux@earthlink.net>
>>Cc: "(Reflector) TowerTalk" <towertalk@contesting.com>
>>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" <n8de@thepoint.net>
>>>>To: "Jerry K3BZ" <k3bz@arrl.net>
>>>>Cc: "(Reflector) TowerTalk" <towertalk@contesting.com>
>>>>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
>
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