Floyd,<br>I agree with Joe. Adjusting the springs will give you a static downweight in the right range, and the piano will play well at pianissimo. This is a good last step.<br><br>The mass of the hammers comes into play much more at fortissimo, where the perceived force is increased, since F = ma. The faster acceleration of the key/hammer system is felt in the fingers of the player. If you have low-mass hammers, you feel like you are falling into the piano. A 10-gram hammer at middle C will feel like 50 when you look at the 1:5 mechanical disadvantage with 3/8" key dip and a 1-7/8" hammer travel. A 9-gram hammer will feel like 45. The hammer mass gives you a dynamic downweight feel. <br>
<br>So, if you want the piano to feel more like a 52-gram-downweight grand, look at the hammer mass.<br><br>John Ashcraft, RPT<br>Portland, OR Chapter<br><br><div class="gmail_quote">On Wed, Jan 18, 2012 at 4:35 AM, Floyd Gadd <span dir="ltr"><<a href="mailto:fg@floydgadd.com">fg@floydgadd.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><u></u>
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<div><font face="Arial">List,</font></div>
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<div><font face="Arial">I have a client (a piano teacher) with a 1906
Heintzman upright piano. She is concerned that the touch feels too
light--that there is too big a distance between what her students encounter on
this piano and what they will find when they play in festival or in an
exam.</font></div>
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<div><font face="Arial">First, an assumption. Let's assume that
the "preferred" pianos against which this is being compared are not just badly
weighted and regulated grands; let's assume the the comparison is against a well
set-up grand.</font></div>
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<div><font face="Arial">The Heintzmans of this era tend to
be well designed and set up. This piano behaves pretty much like any
of its contemporaries in good playing condition. Friction and
wear are not significant contributors to the complaint.</font></div>
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<div><font face="Arial">My experience in altering the key weighting of
verticals has been focused on small pianos from the 1960's. Following a
post in this forum by Stephen Schnell (November 18th, 1996) in a thread called
"Small vertical key flop", I have been backweighting keys for an upweight (with
hammer held out of the way) of 15 grams, then adjusting the hammer return spring
to achieve a downweight of 50 grams, or thereabouts. Add to this the
normalization of friction throughout and thorough regulation (especially damper
timing) and I end up with a much improved piano. But here the initial
problems being addressed tend to be excess effort (against the hammer return
spring) to depress the key, and poor key return.</font></div>
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<div><font face="Arial">The Heintzman I am working on has good key
return. Downweight is somewhat below 50 grams, and I do not recall what
the upweight is, but I seem to remember it being less than 15 grams. There
are, if my recollection is correct, no lead weights in the keys.</font></div>
<div><font face="Arial"></font> </div>
<div><font face="Arial">My inclination is to pursue the same course of
action I have used with the smaller verticals--achieving a target upweight with
springs out of the picture, then regulating the springs to achieve a final
result. I think I should be aiming for a final downweight somewhere in the
order of 50 grams.</font></div>
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<div><font face="Arial">Any suggestions or guidance on this?</font></div><span class="HOEnZb"><font color="#888888">
<div><font face="Arial"></font> </div>
<div><font face="Arial">Floyd Gadd</font></div>
<div><font face="Arial">Manitoba Chapter</font></div></font></span></div>
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