a source for very strong magnets is a harddisk
that you don't use anymore. Get it open, next to
the coil that moves the arms are on each side a
very strong magnet. In this way an old harddisk is still usefull.
They are rather flat so you can use it the way John described.
Thibaud
At 19:44 4-1-2011, John Carmichael wrote:
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p.s.
I just had a thought
Since you can buy magnets that are the same
thickness as standard stained glass (1/8), you
could actually place a magnet into the design of
a leaded stained glass window dial. It would be
surrounded by soldered lead came, just as if it
were a piece of glass in the design
pattern! This would give a VERY strong magnetic
bond since the two magnets would be directly in
contact with each other- without a piece of
glass sandwitched in between them. And the
magnets wouldnt slide around, since they would
be restrained by the ridge of lead came around
them. You wouldnt need a rubber cushion
either, since the gnomons magnet would be touching glass.
I think I like this idea the best!
John
From: [email protected]
[mailto:[email protected]] On Behalf Of Tony Moss
Sent: Tuesday, January 04, 2011 6:28 AM
To: Sundial Mailing List
Subject: Re: Glass on Glass Mosaic Indoor Sundial Windows
On 04/01/2011 05:27, John Carmichael wrote:
Oh, by the way, on a related subject, Ive been
thinking about a neat way of firmly attaching a
gnomon to a glass sundial that would prevent the
glass from breaking if something bumps into the
gnomon (i.e. a window washer or house painter)
You could attach a gnomon that has a flat steel
base to the outside of the glass by placing a
magnet on the inside of the glass. Ive already
tested this and it works great! If somebody
bumps into the gnomon, instead of cracking the
glass, it simply falls off and you just stick it
back on. This method of gnomon attachment is
especially easy to do with a perpendicular rod
gnomon since it just has one point of
attachment
just put a flat steel base on the
rod that will attract the magnet. Simple! No
drilling, nuts, washers, or soldering needed!
Great idea John but I think I would take it a
stage further and have a magnet within the base
of the gnomon for a mutual strong pull through
the thickness of the glass. Ultra-powerful
'rare earth' magnets are easily available these
days in a variety of forms. I have a pair which
are 1/4" cubes and are impossible to separate by
hand with a straight pull. Even sliding them apart is difficult.
Google < rare earth magnets > for infor' and availability.
Tony Moss
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