[pianotech] Upright Key Weighting

[John Ross]

If nothing has been done, a key rebutting, and repining the action flanges will make the action feel heavier.
Lets face it, since 1906 there has been a lot of wear.
John Ross,
Windsor, Nova Scotia
On 18-01-2012, at 8:35 AM, Floyd Gadd 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

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