Thanks all.
My query is not radio related so excuse the off topic.
The application is for supporting a 600 lb V8 engine on a stand. In this
case it would require building an adapter that would permit the engine to be
supported sideways from the exhaust ports.Yes, exhaust ports in the block, a
Ford flathead.
The flat plate will be plasma cut 3/8 or maybe 1/2 inch steel. It will have
a hole in the center to accept a 2" pipe or tube that will be welded and
gusseted.
Requirements to weld cast iron have been discussed and I for one have
suggested NOT trying to weld cast iron to steel plate.
Since several of us are planning to homebrew these adapters the strength of
the material is of prime importance.
Having played with the numbers several years ago when installing a 4el KLM
40M I thought I had the data handy. Not so.
So now I turn to this group of experts to try and bail me out!
Geoff.
----- Original Message -----
From: <K7LXC@aol.com>
To: <geoffrey@jeremy.mv.com>; <towertalk@contesting.com>
Sent: Tuesday, December 24, 2002 1:36 PM
Subject: Re: [Towertalk] Tensile strengths of masts
> In a message dated 12/22/02 2:53:14 PM Pacific Standard Time,
> geoffrey@jeremy.mv.com writes:
>
> > I remember all the various materials, diameters, wall size being
published
> > somewhere.
> > Ive looked all thru my 94 Antenna Manual and no luck.
> >
> > Did I just miss it or where could I find that info?
>
> Good question. The best info I've seen on this is in Dr. Dave Leeson's
> (W6NL, ex-W6QHS) book "Physical Design of Yagi Antennas". It's
out-of-print
> but you might be able to find a copy.
>
> Here's a little recap that's from my practical standpoint. There are
many
> grades of steel and also finishes (drawn-over-mandrill [DOM], seamless,
> welded, etc.) so I'm not going to get involved with those specs.
>
> The specification that you need is 'yield strength'. This is what the
> bending-moment forces are compared to. In short:
>
> STEEL PIPE: i.e. conduit, water pipe, etc. NOT rated for strength (they
carry
> water) but a Schedule 40 or 80 might be in the 35,000 psi yield strength
> range. Only suitable for low windspeed or small antenna arrays (i.e. VHF
> stuff).
>
> ALUMINUM 6061-T6: Yield strength 35,000 psi. Basically the same as steel
pipe
> above.
>
> CARBON ALLOY TUBING: This is the desired material. The most common
available
> is SAE 1026 or 1027. Its yield is around 65,000 psi. Suitable for most ham
> applications; i.e. 2L 40M yagi ten-feet up the mast.
>
> CHROMOLY 4130: This is investment grade piece of steel and typically runs
in
> the neighborhood of 115,000 psi yield.
>
> Most ham mast related hardware (thrust bearings, rotators, etc.) are
> designed around a 2" mast. What you vary is the wall thickness. For BIG
> antennas, moving up to a 3" mast will get you more mast surface area for
the
> antenna boom-to-mast bracket to bite into.
>
> I sell a little software program that calculates antenna mast loads
and
> gives you the mast specs you need. It's called the Mast, Antenna, and
Rotator
> Calculator (MARC) program and it's ten bucks at <A
> HREF="http://www.championradio.com";>www.championradio.com</A>.
>
> I will be handling masts shortly and they'll be on the website.
There'll
> be an announcement when it's ready. In the meantime, drop me a line if
you've
> got any questions.
>
> Cheers,
> Steve K7LXC
> Champion Radio Products
>
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