Touch Weight

[Ed Sutton]

Jim-

What a wonderful post!

This could become a great article for the Journal.

Perhaps this could be the start of a Guild "basic standard" for hammer
replacement.

Thank you.

Ed Sutton


Jim wrote:
> Paul would like all the confusion to be removed from this discussion, and
> for us to provide him with a simple soultion for optimizing an action.
> Paul, try this.
>
> 1.  Start with a well-designed action.  Re-designing an action is not what
> you are wanting to do.
>
> 2.  Use hammers that are uniformly graduated from bass to treble - no large
> or sudden variations in size or weight along the way.  That will give you
> hammers with evenly graduated mass, bass to treble.
>
> 3.  Use the recommended parts for that particular action.  We assumed a
> well-designed action to begin with, so maintain the original design,
> ratios, spread, clearances, etc.
>
> 4.  Check everything for friction, beginning with the keys alone, befure
> you go any further.  Keys free to move - no binding - very tiny bit of
> side-play at the front bushings - barely enough to feel - no more than that
> - no side slap - no binding - no "pulley keys".  Check everything else.
> Everything snug, nothing loose, but nothing binding, jack centers
> absulutely free.  Don't worry about whether the shanks are round or
> octagonal.  It won't matter, as long as you stwy with the correct
> dimensions and high-quality parts.  I'm talking about the keys and action,
> not the back-action or dampers.  That's another matter.
>
> 5.  Do a preliminary action regulation.  Double-check for any possible
> problems, especially any tight centers or bushings, or anything loose.
> Deal with all that stuff first.
>
> 6.  Weigh off for even BALANCE WEIGHT (down-weight + up-weight / 2).  The
> actual balance weight I aim for will depend upon what the piano owner
> wants.  If you have done the preliminary things well, you will find that
> there won't be any big differences in balance weight and up-weight from key
> to key after you check the down weight.  There will always be some.  But if
> you aim for even balance weight, you won't be way off when the friction
> changes, as it will surely do, sooner or later.
>
> If you follow this routine, you will end up with an action that has an even
> response from bass to treble.  But if you start with hammers that are not
> uniformly graduated from bass to treble, and friction that is not
> consistent, and then try to compensate for it with the key leads, I can
> assure you that you will end up with an action that does NOT have a
> consistent feel from key to key.
>
> David Stanwood has a patented system for doing this that we have all read
> about or seen.  I have my own system, different from David's, that I was
> privately developing when David first come on the scene.  Mine is still
> under development, so I won't go into it right here on this list.  I have
> not yet decided what to do with it.
>
> But Paul, if you will follow the simple procedure I outlined, you will end
> up with an action that is consistent from bass to treble, and you will not
> infringe upon anyone's patent claims.  You will just be doing what has
> already been done for years, but you will be doing it well.  From time to
> time, some manufacturers have not been as careful as they should have been.
>
> The problems I often find in old pianos are:
>
> 1. The hammer weights were not uniformly graduated to start with.
> 2. The friction was not uniform to start with.
> 3. The factory tech tried to compensate with key leads.
>
> The result was that the down-weight might be even, but the key-to-key
> action response would not be even throughout the dynamic range, and no
> amount of regulation would make it so.  Furthermore, when the friction
> changed, the down weight would be uneven.
>
> Sincerely, Jim Ellis
>
>
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