Touch Weight

[David Love]

I think this is good advice except that starting with a well designed
action is often the problem.  One needs some method of assessing whether or
not the action is, in fact, well designed, or at least whether the weight
of the hammer is a good match for the overall leverage in the action.  This
is not that difficult to do.  Taking a reading of some sample notes in up
weight, downweight, front weight, hammer weight (minimally) can give you a
good sense of whether you might have problems and need to make some
adjustments to the hammer weight or, most easily, the knuckle position.  A
rudimentary understanding of Stanwood methodology is not difficult to
grasp.  He has published several articles in the journal in years past
which, if read carefully, will give you a working knowledge of his system.

Additionally, while using recommended parts for the system will often yield
good results, sometimes they will not.  Sample kits are available from
manufacturers like Renner and Abel that will give you a quick and easy way
to see whether the parts you are going to put on there will work and not
cause weight problems in either direction.   New hammers from Steinway are
much heavier than the older hammers from the 20's.  If you combine those
hammers with the original dimension parts, you will probably have a weight
problem.  When putting actions together, measure twice cut once.  Take the
time to put on samples and regulate and weigh off to determine if you are
in the ballpark.  Become familiar with basic Stanwood ideas so that you can
determine whether your new parts will cause a jump in the required front
weight (leads) to get your desired balance weight.  

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: James Ellis <claviers@nxs.net>
> To: <caut@ptg.org>
> Date: 1/1/2004 5:17:49 PM
> Subject: Touch Weight
>
> Here are a few comments following the latest posts on related subjects.
>
> Richard,
> I was using the term "touch-weight" to refer generally to the static
> measurements, "doun-weight", "up-weight", "balance-weight", and
"friction",
> of the total action (minus the dampers) as these appear at the key front.
> I do know what "balance weight" is.  We say "weight" because that's what
we
> use to measure these forces at the key fronts.
>
> Paul Legard, 
> 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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