some excellent suggestions from the DC ham....
FWIW - I use blocking of the boom to prevent crushing made form "plastic
lumber" - it is currently very in vogue to use this stuff for decks,
etc... it is recycled 2 litter pop bottle with some wood strands mixed
in - very environmentally conscious to use it.
If you have access to a lather this stuff turns like a charm in no time
you can spin it to the right diameter and when the bolts tighten down
that boom wont be "yielding"
I have had good luck drilling a small hole in the center of the piece to
be turned and then put a lag bolt into the mass... drive the lag bolt
all the way into the block. This will give you a six sided clamp on
point which is great for the three jawed chuck on the lathe... the other
end goes on a pointy rotatable center. For 3: boom you can get the
plastic lumber equivalent of a 4X4 - if you get lucky you can convince
them to cut a ten foot piece back to eight foot and sell you the two
foot which is more than you will need! Remember to repeatedly measure -
once it is too small the next stop is for a smaller boom!
Only down of using boom "plugs" is if you live in a climate where there
is freezing - trapped water can freeze inside the boom and cause
failure! fortunately here in FL we don't have that problem... although
I recommend a weep hole... did not do that on the first boom I
plugged... after taking the heavy antenna down I heard the water inside
the boom - drilled the weep and it "peed" for 10 minutes!
GL
Jim, K4OJ
Eric Scace K3NA wrote:
> Galling of stainless steel hardware can be prevented by using anti-seize
> compound. Suitable compounds are available at auto supply
> stores.
>
> Not sure what you are trying to hold. If you are trying to keep the boom
> from rotating, maybe an extra U-bolt will help. It might
> also help to place some material inside the portion of the boom on which the
> U-bolts bear, so as to keep the boom round while the
> U-bolt is compressed. A wood dowel of appropriate diameter is one approach.
> If the boom compresses or deforms over time, the
> U-bolt will become loose.
>
> If you are simply trying to tighten things enough so that the nuts don't get
> loose again, use nylock nuts.
>
> Hope this helps.
>
> -- Eric K3NA
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com]On Behalf Of Joe - KC2TN
> Sent: 2003 July 18 Friday 15:30
> To: kk9a@arrl.net; TOWERTALK@contesting.com
> Subject: RE: [TowerTalk] SS "U" bolts
>
>
> I've used DX Engineering's 2 1/2" SS U bolts on my KT36XA mast bracket and
> they DON'T hold.
> You can't tighten them enough without galling. I visited DX Engineering
> while at Dayton this year and expressed my displeasure with their 5/16" vs
> 3/8" SS U-Bolts and they just shrugged.
>
> I'm also looking for 2 1/2" x 3/8" SS or Galvanized U-Bolt source.
>
> Joe - KC2TN
>
>
> _______________________________________________
>
> 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.
>
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