[CAUT] Down Weight Too High With New Hammers

[Paul Milesi, RPT]

Thanks, Fred, for this reply.  Your first paragraph states quite clearly
what my intuition was telling me so far as the implications of DW and UP
insofar as it being more of a relative weight issue (keys/hammers) and
possibly small geometry changes that make old and new parts not quite
compatible.  I also recognized that rep springs are not in play prior to
let-off, which is why I stated in my first post that I didn't think that was
the source of the problem.  I feel a "heaviness" in my hands/fingers when I
touch the piano, and as a pianist I just know it's not right.  The
measurements of course bear this out.

Having said that, I don't rule out friction, and as time permits over the
next few days I will re-examine critical interfaces using the very helpful
input others have offered here.

I have also just located 2 NYI Steinway repetitions from the last set I put
on an M, and am anxious to take them to the school and compare them with the
older ones on the D, see what's up.  Installing them side-by-side might
yield some interesting comparisons, if everything else is equal.

Thanks, everyone, for your input.  I'll keep you apprised in the days ahead.
I won't have a large block of time for this piano for at least a couple days
now, so there's time to mull things over, try a thing or two, etc.
-- 
Paul Milesi, RPT
Staff Piano Technician
Howard University Department of Music
Washington, DC


> From: Fred Sturm <fssturm at unm.edu>
> Reply-To: <caut at ptg.org>
> Date: Mon, 23 Aug 2010 21:22:19 -0600
> To: <caut at ptg.org>
> Subject: Re: [CAUT] Down Weight Too High With New Hammers
> 
> On Aug 23, 2010, at 2:53 PM, Paul Milesi, RPT wrote:
> 
>>  Just wondering if
>> this touchweight issue is common when putting new hammers on a
>> Steinway D
>> from this period, and if there is a typical or common remedy or
>> approach to
>> solving the problem.
> 
> 
> From what you have said, it appears to be a weight and geometry
> issue. Those high upweights indicate reasonably low friction. Key
> leading on the heavy side sounds typical and removes the option of
> adding lead (though I wouldn't rule it out entirely - not having seen
> what you have seen, anyway). Roger Jolly is probably right in saying
> that cleaning and lubing the rep springs and grubs will make it feel a
> little lighter, but I don't believe it will change downweight/upweight
> (they aren't engaged during the part of key travel that is measured
> for weight). The change in feel will occur at the end of the
> keystroke, and can be very noticeable if there was caked grease and
> crud in there.
> I don't understand how the old geometry wipp can cause a difference
> in weight/ratio compared to the new one, but experience seems to say
> it can. After all, the capstans are touching the wipp heels at the
> same point, and the jack/rep lever is contacting the knuckle at the
> same point, whether it is new style or old. I guess it must have to do
> with the angle at which the jack addresses the knuckle, as that
> certainly does change (enough to require different thickness let off
> buttons). It wouldn't seem that changing one factor - the knuckle
> distance - would make that much difference, but it seems that it does.
> The newer wipp has very subtle differences in things like jack
> profile. This thread makes me curious to look very closely at just
> what those differences actually are.
> In any case, as a practical matter, the easiest thing to address
> might be weight. Reduce each hammer 1 gram, and you are in a better
> ballpark. Not a walk in the park, but doable (or close - 1 gram is
> about the max you can comfortably remove from a hammer by re-arcing
> and tapering). It does require removing and replacing all the hammers
> and shanks (and re-aligning), and a bench disc sander at a minimum,
> with Spurlock's tail arcing device or equivalent. Tapering can be done
> fairly evenly by timing and feel (how long and hard you hold the
> hammer against the sanding disc, balancing from one side of the hammer
> to the other). A scale to weigh before and after. You will need to
> taper into the felt area (not all the way to the crown) to get enough
> weight reduction.
> If it weren't a Steinway, I'd look at a quick geometry change using
> split balance punchings. But it is a Steinway, so no soap. At least
> not that I know of. Maybe Ed Sutton's idea about shimming the wipp
> would work. Worth the experiment.
> Regards,
> Fred Sturm
> University of New Mexico
> fssturm at unm.edu
> 
> 
> 
> 
> 
>