I am wondering what type of hardware would be the safest to use for 1) Joining
the wood 4 x 4 and
2) hanging the swing.
Thanks,
Nancy
----- Original Message -----
From: Lee A. Stone
To: blindhandyman@yahoogroups.com
Sent: Wednesday, September 09, 2009 1:31 PM
Subject: Re: [BlindHandyMan] Calculating load capability
each of you are talking about bolting. are we talking about carriage
bolts? Lee
On Wed, Sep 09, 2009 at 12:01:29PM
-0400, Spiro wrote:
> Could an A frame help this any? Or, an upright, with a short top piece,
> and then a diagonal reaching back to that?
> Wondering if running a piece of wood from front upright to back up right,
> which encloses the foot of the diagnal upright, bolting that horizontal
> piece to the concrete between the uprights might also change the pivot
> point some?
> Is there any possibility of making it look like a two sail from a main
> mast
> set up?
>
>
>
>
>
> On Wed, 9 Sep 2009, Dan Rossi wrote:
>
> > Nancy,
> >
> > I agree that you probably don't have to worry about the posts snapping off
> > but remember that as the swing moves forward, the uprights are attempting
> > to pivot around the point where they cross the floor of the porch, meaning
> > that the bottoms of the posts are pulling away from the wall of the porch.
> > Not only that, but since the floor of the porch is the fulcrum, you have a
> > six foot lever arm above, and maybe a ten inch lever arm below, so the
> > force at the top of the uprights, as the swing moves forward, is
> > multiplied by about 7 times and that is a force attempting to pull the
> > bolts out of the porch wall.
> >
> > I would think that sinking the posts into concrete a couple of feet down
> > would go a long way to helping the system be more structurally stable.
> >
> > We've just had a discussion on the issues of burying posts or not, so you
> > can make your own decision on that point, but I think that it might be
> > prudent in this case.
> >
> > As far as chain strength, the guys at any big box store should be able to
> > tell you what the relative strengths are of the various gauges of chain.
> > I don't have any real knowledge of that.
> >
> > --
> > Blue skies.
> > Dan Rossi
> > Carnegie Mellon University.
> > E-Mail: d...@andrew.cmu.edu
> > Tel: (412) 268-9081
> >
--
You may have heard that a dean is to faculty as a hydrant is to a dog.
-- Alfred Kahn
.
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