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[TowerTalk] drilling chromoly es similar pipe

To: <>
Subject: [TowerTalk] drilling chromoly es similar pipe
From: (Bob Wruble)
Date: Tue, 1 Jul 1997 07:55:49 -0700
i hve yet too see an unpinned mast that dids not eventually
rotate in the clamps......

pin or not to is the question........i mostly do not as i wud rather
re orient the beam time or tw9 a year than tear up a rotator....
blew the gears outa
a coupla  of hdr 300's a few years ago.....before they beefed up
the gears!!   for small arrays like a tri-bander i wud pin... 


> From:
> To:;
> Subject: Re: [TowerTalk] drilling chromoly es similar pipe
To: <>
> Date: Tuesday, July 01, 1997 4:30 AM
> Yeah, I saw that.  I dont care for the idea of using rubber in a mast
> clamp.  I doubt it will hold very least around here.
> Rubber is not a particularly long-lived product.  Also, if you do that and
> add it to the cradle (in addition to the clamp), you'll throw the mast off
> center.  My goal is and always will be to install something to last for as
> long a period as possible without requiring maintenance, and that sounds
> like high maintenance to me.  I still say that if you have the clamp
> tightened properly and add the through bolt, you are not going to have any
> problems as long as you havent overloaded your rotator.  (If  you have a
> Yaesu rotator, all bets are off!)  It's also important to pay attention to
> dynamic balancing, which will go a long way to keep things from spinning in
> the first place.  Then if you still have problems, maybe it's time for a 3
> inch mast!
> I think if you have a tight clamp, with a hardened thru bolt in a chromoly
> mast and you shear something, you've got a design problem.
> 73, Tyler K3MM
> To:   Tyler G Stewart/BENN/CEC
> cc:
> Subject:  Re: [TowerTalk] drilling chromoly es similar pipe
> Tyler....
> Agreed about the bolt...but...most people believe (wrongly) that everything
> will stay the same.  When you have wind, rain, sleet, snow, and various
> other forms of weather above the roof line or tree line, something is
> stressed.  If you use a bolt through a hole in the mast...the bolt or the
> mast WILL give.  I understand that the bolt is not meant to take ALL the
> torque, but people rely on them way to much.  I have seen bolts break and
> holes wallow out.  Just a hugh expense and an accident waiting to happen.
> Never...NEVER....drill a hole in a mast.  It is not worth it.  The rotation
> of the beam will severelt over tax the bolt and the mast over time.
> Guranteed.  K7LXC came up with a neat idea I had never heard of..and that
> is
> to wrap the mast that goes into the rotor with some rubber and tighten the
> rotor down.  I could see that gripping better than metal on metal.  Never
> used the technique...but plan to shortly.
> Of course...this is IMHO.
> Lee
> At 04:59 PM 6/30/97 -0400, you wrote:
> >
> >Negative.
> >
> >The bolt thru the mast isnt meant to take all the torque.  It's only there
> >for insurance.  In case the clamp slips, it's not going to rip out coaxs
> >and things like that.  It should, however, assist the clamp in some small
> >amount...just dont rely on it exclusively.
> >
> >73, Tyler K3MM
> >
> >
> >
> >
> >
> > on 06/30/97 12:21:10 PM
> >
> >To:
> >cc: (bcc: Tyler G Stewart/BENN/CEC)
> >Subject:  Re: [TowerTalk] drilling chromoly es similar pipe
> >
> >
> >
> >
> >At 01:15 AM 6/30/97 -0500, you wrote:
> >>i am doing some antenna repair and part of the repair requires drilling
> >>heavy mast.  by heavy i mean 1/2" wall thickness chromoly steel.  after
> >>burning up several bits and a few $$$ let me pass this tip:  use a
> >>masonry bit ( carbide tip ), lowest speed on drill press, and lot of
> >>oil.  the most expensive bit i have used only did about 1/8 inch deep
> >>( cost about $12 ) and the least expensive was the carbide tip masonry
> >>type.  it has taken me over 4 hours of drilling to make a 5/8 hole in
> >>some of this stuff but i am betting it wont bend!
> >>
> >>put em up high and hope they stay up!
> >>
> >>73, de bud
> >Opinion:  I don't like any holes in my mast.  Now, I have never use
> >Chrome-Molley masts and I know they are hard, but I have used steel masts.
> >I have drilled holes to connect masts together..etc..etc...and the holes
> >wallow out over a period of time.  The beam then really moves in the wind
> >and damages the rotor.  I have tried all sorts of schemes to stop this
> from
> >happening...using shoulder bolts, heating the metal and pressing on the
> >bolts, etc...etc.  It will wallow out.  The best solution is
> >never..NEVER...drill a hole in a mast.
> >Lee
> >
> >
> >--
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