I am a mechanical engineer and I second the idea of making a plate to set
the angle.
Steve
______________________________ Reply Separator _________________________________
Subject: Re: Guy Anchors on a flat concrete roof
Author: ken smith <kgsmith@onlink.net> at ccmgw1
To: <towertalk@contesting.com>
Date: 8/26/96 10:13 PM
At 08:30 PM 8/26/96 -0700, you wrote:
>
>Heres my question. Rohn specifies that the normal guy anchor should
>be in line with the guy wires. My problems is that I can only drill
>straight down into the concrete.
>
> / <----- guy wire
> /
> O/ <------------ guy anchor (probably a forged eyebolt)
>_____|_______ Roof
> |
> | <-------- Eyebolt surrounded by epoxy made for the job
>
>
>As you can see, the guy wire is going to want to bend the guy anchor.
>But I can't see anyway around it. The dealer did not suggest drilling
>the hole at a 45 degree angle.
>
>I am estimating that the eye bolt will only extend a few inches above
>the roof so as to leave just enough room to install an equalizer plate.
>
>Does anybody have any suggestions or do you think this will work fine?
>
>73
>
>(p.s. need to get this done before the October contest season, HI)
>
>
First, I'm not a Mechanical engineer, so this is a personal opinion on the
dynamics of what you are proposing. First, I don't think that sticking an eye
bolt up in the air with a bending moment is a good idea. Most of the concrete
anchors give a spec for holding a force strait out, with a sheer strength for
the bolt. But your proposal is like a yagi ten feet up the mast as opposed to
one foot up the mast.
How about looking at making a plate that has the required angle built in to
it for the guy attachment, and having concrete anchors hold the plate tight
to the roof. This would eliminate a bending moment on the bolts.
Ken Smith
VA3SK
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