[CAUT] Down Weight Too High With New Hammers

[Ed Sutton]

Paul-

Fred has given the intermediate logic I was too tired to work through last 
night.
 Another option would be Scott Jones' TouchRail installation.

Ed

----- Original Message ----- 
From: "Paul Milesi, RPT" <paul at pmpiano.com>
To: "PTG CAUT List" <caut at ptg.org>
Sent: Tuesday, August 24, 2010 1:51 AM
Subject: Re: [CAUT] Down Weight Too High With New Hammers


> 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
>>
>>
>>
>>
>>
>>
>
>