Dangerous territory for me; I am not an engineer.
That said, see attached pdf. Could a cable or rod strung internally in
the hollow pole/gnomon be placed under tension, causing the pole to bow
upwards against gravity? The rod or cable could have a turnbuckle to
make the tension adjustable, u
> Oh, I concur wholeheartedly. If it's an end attachment it's one thing, but
> if you want to fill the tube with it so as to make the tube stiffer, there
> are actually better ways.
One idea that I see occuring naturally in flight feathers of birds. To prevent
the quill tube wall from collap
ld be covered if it
doesn't fit with the aesthetics of the rest of the design.
John C, looks like that guy can do anything with metal. Cool!
John B
-Original Message-
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Thu, 2 Oct 2008 9:49 am
Subject: Re: Preventing Rod Gnom
x27;ll probably take months to
finish.
Good thought though about the cable!
John C
From: Chris Lusby Taylor [mailto:[EMAIL PROTECTED]
Sent: Thursday, October 02, 2008 3:14 PM
To: John Carmichael; 'Sundial List'
Subject: Re: Preventing Rod Gnomon Bending
Hi John,
The
hael
To: 'Sundial List'
Sent: Wednesday, October 01, 2008 7:46 PM
Subject: Preventing Rod Gnomon Bending
Hi Guys:
I'm designing a large 15 foot tall southwest declining nearly vertical dial
that will have a very long polar axis oriented rod gnomon. But I've co
easier.
Thanks
Roger! I hope the other guys agree with you.
John
C
From: Roger Bailey
[mailto:[EMAIL PROTECTED]
Sent: Thursday, October 02, 2008 10:02 AM
To: [EMAIL PROTECTED]; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Subject: Re: Preventin
On Thu, October 2, 2008 10:30 am, John Carmichael wrote:
>
>
> Hi Roger:
>
>
>
> This comment of yours is most important, and if itâs true, then that
> would be the way to go. I trust you, so Iâll probably do what you say.
>
>
>
> You said:
>
> John C, I would not put a box section inside the
PROTECTED]
Sent: Thursday, October 02, 2008 10:02 AM
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: Preventing Rod Gnomon Bending
Hello John B , John C and all,
The spreadsheet is excellent. I agree. "Don't speculate, calculate. The
spreadsheet
dials.com/>
(educational) Sundial Cupolas, Towers & Turrets:
http://StainedGlassSundials.com/CupolaSundial/index.html
From: Lloyd Tackitt [mailto:[EMAIL PROTECTED]
Sent: Thursday, October 02, 2008 9:53 AM
To: John Carmichael
Subject: Re: Preventing Rod Gnomon Bending
One othe
t;
To: John Carmichael <[EMAIL PROTECTED]>; 'Sundial List' <[EMAIL PROTECTED]>
Sent: Wed, 1 Oct 2008 8:29 pm
Subject: Re: Preventing Rod Gnomon Bending
Hi John,
In general, a tube is stiffer than a rod if you are looking at bending from the
weight. This is why structures a
al Message-
From: Larry Bohlayer / Celestial Products <[EMAIL PROTECTED]>
To: 'Sundial List' <[EMAIL PROTECTED]>
Sent: Wed, 1 Oct 2008 7:44 pm
Subject: RE: Preventing Rod Gnomon Bending
John,
In the structural engineering of bridges
lt;[EMAIL PROTECTED]>; 'Sundial List' <[EMAIL PROTECTED]>
Sent: Wed, 1 Oct 2008 8:29 pm
Subject: Re: Preventing Rod Gnomon Bending
Hi John,
In general, a tube is stiffer than a rod if you are
looking at bending from the weight. This is why structures are made f
nor sundial or
other structural design.
From: John Carmichael
Sent: Wednesday, October 01, 2008 11:46 AM
To: 'Sundial List'
Subject: Preventing Rod Gnomon Bending
Hi Guys:
I'm designing a large 15 foot tall southwest declining nearly vertical dial
that will have a very
John:
I haven't read all of the replies - hope I'm not repeating.
Use a unidirectional wound carbon fiber tube. Nothing is
stiffer. Once you decide on a manufacturer he can tell you exactly
how much it would deflect (if any) at the angle of tilt (they test
them). Thermal expansion and cont
Another thought...
Perhaps you could have the pipe fabricated of thinner material but with an
internal welded structure for the length of the pipe. In crossection a "+"
or a honeycomb. I think that should reduce deflection in the center. (while
raising the cost significantly). :-)
Al
: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John Carmichael
Sent: Wednesday, October 01, 2008 2:47 PM
To: 'Sundial List'
Subject: Preventing Rod Gnomon Bending
Hi Guys:
I'm designing a large 15 foot tall southwest declining nearly vertical dial
that will have a
1 Oct 2008 5:46 pm
Subject: Re: Preventing Rod Gnomon Bending
Hi John C,
Off the top of my head, 25' between supports is going to be a bit long for 2"
outside diameter in steel. 4" might do it, will have to lay some numbers on it
and quit guessing.
Glad to hear it is sup
: John Carmichael <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Wed, 1 Oct 2008 4:36 pm
Subject: RE: Preventing Rod Gnomon Bending
Hi John B:
The minimum diameter of the gnomon is 2” (5cm) because if it’s
any thinner the shadow will be too
: Wednesday, October 01, 2008 4:10 PM
To: [EMAIL PROTECTED]
Subject: Re: Preventing Rod Gnomon Bending
Hi John,
You actually have two questions here, and several engineers on the list to
answer them.
1) What should I do to prevent its deflection under its own weight?
2) What should I do to
rious things.
Best,
John B
-Original Message-
From: John Carmichael <[EMAIL PROTECTED]>
To: 'Sundial List' <[EMAIL PROTECTED]>
Sent: Wed, 1 Oct 2008 11:46 am
Subject: Preventing Rod Gnomon Bending
Hi
Guys:
I’m designing a l
Hi Guys:
I'm designing a large 15 foot tall southwest declining nearly vertical dial
that will have a very long polar axis oriented rod gnomon. But I've come
across a potential problem that I've never had to deal with before and am
seeking your expert advice or suggestions.
Setup:
The gno
21 matches
Mail list logo
