Floyd, 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. 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. So, if you want the piano to feel more like a 52-gram-downweight grand, look at the hammer mass. John Ashcraft, RPT Portland, OR Chapter On Wed, Jan 18, 2012 at 4:35 AM, Floyd Gadd <fg at floydgadd.com> wrote: > ** > List, > > 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. > > 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. > > 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. > > 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. > > 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. > > 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. > > Any suggestions or guidance on this? > > Floyd Gadd > Manitoba Chapter > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120118/ccc489bd/attachment-0001.htm>
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