On Mon, 24 Apr 2006 21:01:28 +0100, David Billington wrote:
Another good way to demo this is using a cylindrical magnet and drop it
through a copper tube like used for plumbing. Re your sorting method I
believe this is similar to how many vending machines validate that a
coin is what it should be rather than a counterfeit.

As soon as I can find/fab a good ramp, I'm good to go. Keeping the
friction down while the guidance is still good, is the trick. I know
two ways not to do it at this point.

But yes, fun with eddy currents is a great desk-toy.