Author: BobWDate: 20:28 11-06-08
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For those of you that haven't seen this in action:
http://www.youtube.com/watch?v=pcVG6c_OvYU&NR=1
An eBay seller called magnet4less has a nice variety of neodymium magnets. I
bought some of his 1/2" N48 sphere magnets. They work very well in 3/4"
copper pipe.
The effect is amazing -- especially when you first demonstrate that the
magnet is not attracted to the copper.
I dropped one through a 10' piece of 3/4" copper pipe and it took about 13
seconds to make it all the way through. It works well in short pieces, too.
Bob
--
== NOTE: I automatically delete all Google Group posts due to uncontrolled
SPAM ==
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Author: Stephen J. RushDate: 23:14 11-06-08
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On Wed, 11 Jun 2008 17:28:03 -0700, BobW wrote:
> For those of you that haven't seen this in action:
>
> http://www.youtube.com/watch?v=pcVG6c_OvYU&NR=1
>
> An eBay seller called magnet4less has a nice variety of neodymium
> magnets. I bought some of his 1/2" N48 sphere magnets. They work very
> well in 3/4" copper pipe.
>
> The effect is amazing -- especially when you first demonstrate that the
> magnet is not attracted to the copper.
>
> I dropped one through a 10' piece of 3/4" copper pipe and it took about
> 13 seconds to make it all the way through. It works well in short
> pieces, too.
Cool. I've seen several demonstrations of eddy-current braking, but this
is the best one that doesn't require a big electromagnet.
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Author: Bob EldDate: 00:36 12-06-08
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"BobW" <nimby_NEEDSPAM@roadrunner.com> wrote in message
news:lbqdnToni6IE8M3VnZ2dnUVZ_tvinZ2d@giganews.com...
>
> For those of you that haven't seen this in action:
>
> http://www.youtube.com/watch?v=pcVG6c_OvYU&NR=1
>
> An eBay seller called magnet4less has a nice variety of neodymium magnets.
I
> bought some of his 1/2" N48 sphere magnets. They work very well in 3/4"
> copper pipe.
>
> The effect is amazing -- especially when you first demonstrate that the
> magnet is not attracted to the copper.
>
> I dropped one through a 10' piece of 3/4" copper pipe and it took about 13
> seconds to make it all the way through. It works well in short pieces,
too.
>
> Bob
I have some small Boron Iron magnets about 1/4 in. in diameter that slowly
slide down an inclined aluminum cookie sheet. Its a great demo. Of course
the same magnets slide very fast down a piece of cardboard to illustrate the
difference.
Interestingly these magnets stick to the black specks in our granite counter
top. Obviously these specks are some iron mineral in the granite.
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Author: Tim WilliamsDate: 01:35 12-06-08
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You haven't seen jack until you've tried it with a solid silver bar. The
thickness makes a lot of difference (more than the 2% conductivity
difference ;-), but there's the allure of pure silver too). It takes
seconds *per inch*. On an inclined slab, it's so "sticky" the magnet starts
tumbling down in slow motion.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
"BobW" <nimby_NEEDSPAM@roadrunner.com> wrote in message
news:lbqdnToni6IE8M3VnZ2dnUVZ_tvinZ2d@giganews.com...
>
> For those of you that haven't seen this in action:
>
> http://www.youtube.com/watch?v=pcVG6c_OvYU&NR=1
>
> An eBay seller called magnet4less has a nice variety of neodymium magnets.
> I bought some of his 1/2" N48 sphere magnets. They work very well in 3/4"
> copper pipe.
>
> The effect is amazing -- especially when you first demonstrate that the
> magnet is not attracted to the copper.
>
> I dropped one through a 10' piece of 3/4" copper pipe and it took about 13
> seconds to make it all the way through. It works well in short pieces,
> too.
>
> Bob
> --
> == NOTE: I automatically delete all Google Group posts due to uncontrolled
> SPAM ==
>
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Author: Rich GriseDate: 16:27 12-06-08
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