Journal Articles

[Richard Brekne]

Hi Jim.

First and formost, thank you muchly for your kind words. The whole 
experience with the magnetic assist action has been quite a learning 
experience for me, and a lot of fun as well.  I do want to publicly 
thank Bob Hohf and his staff for the absolutely dynamite presentation of 
the article.

Over to Jim Hudsons article tho... Dont you think a whole 3 mm letoff is 
a bit overkill on the safe side ?  Where do you generally like letoff 
and drop yourself, and why ?

Interesting to find so much variance in this seemingly simple point. 

Cheers
RicB



James Ellis wrote:

>This is one I can't resist, so I am going to jump in here with my "two
>cents worth" (No, it's not about tuning).
>
>"PRACTICAL CONCERT WORK" by Jim Hudson, June 2004:
>
>What no one seems to have noticed is the word "Practical" in the title.
>That sets the tone for the whole article, but some readers did not seem to
>hear it.  Fred Sturm says he prefers to set let-off at 1/32 inch.  Well, I
>don't.  If I set it like that, I'd be in trouble for sure.  That's right at
>the very edge of blocking, and even if it does not block outright, it does
>not produce a clean let-off, and that results in occasional bizarre sounds
>when the hammer does not completely clear the very first-half cycle of the
>strings vibration.  David Love says setting let-off like this is
>"dangerous", and I agree.  Otto Keyes says "consistency" is what one should
>strive for, and I agree with that too.  But if you regulate to a "gnat's
>eyelash", Bill Garlick has said you better stick around for the concert.
>True, but that might be too late.
>
>In all this nit-picking with Jim Hudson's article, did no one mention drop
>regulation?  If you want consistent response for playing very soft
>passages, you had better pay close attention to that too, as well as to
>consistency in the regulation of the repetition springs, and everything else.
>
>"MAGNETIC ASSIST FOR GRAND PIANO ACTIONS", by Richard Brekne, June 2004:
>
>With all this interest in nit-picking Jim Hudson's article, am I the only
>one who has taken a special interest in Brekne's article?  This is really
>neat!  It is innovative.  It is clever.  There are other magnetic touch
>systems around, but this one has something clever that the others don't.
>One of the first questions that popped into my head was the non-linear
>decrease in magnetic repulsion as the two tiny magnets move farther apart
>as the key moves.  Richard takes care of that by suggesting a second pair
>of magnets behind the capstan, which would be attracting.  Thus, the
>non-linear repulsion of the first pair would be compensated by the opposing
>non-linear attraction of the second pair.  Very clever indeed!!  In other
>words, the combined effects would apply a measured force tending to rotate
>the front of the key downward and the wippen upward around a pivot at the
>point where the capstan touches the wippen cushion.  Since the capstan
>never leaves the wippen coushion, the action ratio is not changed.  All
>that happens is that the need for lead in the fronts of the keys, and the
>moment of inertia is reduced, without the use of springs.  The thing to
>watch out for here will be that the spacing of the magnets will need to be
>regulated as the capstan depresses farther into the wippen cushion over
>time.  This, in my opinion, is very clever and very innovative, and I for
>one would like to see how it all plays out in the end.  Congratulations,
>Richard!
>
>Sincerely, Jim Ellis
>
>
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>
>  
>