[CAUT] about magnets

Ed Sutton ed440@mindspring.com
Tue, 22 Mar 2005 17:41:41 -0500


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O, Great Minds of Caut!

I have heard tell that Petrof is producing grand pianos with a magnetic assisted action, soon to arrive in our neighborhood.

The magnets are installed in the wippen rail and wippen in repelling orientation so that the magnets lift the wippen similar to a wippen assist spring.  The touchweight can be refined by adjusting the magnets similar to a screw regulated wipen assist spring.  Functionally it seems identical to a wippen assist spring.

When I asked how it differed from a wippen assist spring I was told "Springs wear out, but magnets last forever."  I would be interested in educated comments on that statement.  The magnets will be held continuously in opposition and "compression."  Will they grow weaker over years? decades? or will they last forever?

How does this compare with assist springs?  Do wippen assist springs grow weaker over time?  Faster than magnets?

Jim Ellis, I thank you in advance!

Sincerely,
Ed Sutton
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