[CAUT] Down Weight Too High With New Hammers

[Paul Milesi, RPT]

Thanks much for these discussions.  I will be making best efforts to obtain
useful data, and now have a better idea of what might be needed.  FWIW, I
did sample dip on several keys in different registers, because I wasn¹t
getting much, or any, aftertouch with the hammer line and let-off I¹d set.
The dip was (and still is) roughly 9-9.5mm throughout, or less than .375².
I am catching on now that, assuming the piano was playing well when set up
with this dip with original hammers, that likely means a relatively high
action ratio?  Obviously I haven¹t set dip yet with the new hammers, only
roughed things in to make sure everything works in relation to others as
they¹re supposed to.

Again, the piano was so beat up, played so hard (gospel church music all
week), that things were pretty tattered.  Compound that with, one year ago,
my having to literally just screw the new hammers on the rail one morning,
align jacks quickly, and set let-off just to get the piano to play somewhat
for an important event for the university¹s new president.  I mean, it
barely played.  But I tuned it and they used it in a big ceremony.  That was
the beginning of the resurrection, and it was another year before I could
get the piano moved to a space where I could really work on it.  The point
of all this is, to give you a sense of why I don¹t have a lot of carefully
gathered specs, etc., and have not exactly worked methodically.  Just
realities.  The work started on an emergency basis, and we¹ve gone from
there to wanting to make this a recital piano.  Miracles never cease....
-- 
Paul Milesi
Registered Piano Technician (RPT)
(202) 667-3136
(202) 246-3136 Cell
E-mail:  paul at pmpiano.com
Website:  http://www.pmpiano.com




From: David Love <davidlovepianos at comcast.net>
Reply-To: <caut at ptg.org>
Date: Wed, 25 Aug 2010 07:40:52 -0700
To: <caut at ptg.org>
Subject: Re: [CAUT] Down Weight Too High With New Hammers

Until we have more info from Paul it¹s difficult to know what to suggest.
The original is probably 16 mm and Paul has changed to 17mm on the knuckle.
That will increase the dip specs but .415 is a fairly deep dip and would
suggest an action ratio that is on the lower side already (assuming that
measurement is accurate).  So unless the hammers are really monsters (which
they could be) then I would expect one to be able to achieve a reasonable FW
even if it is with a moderately higher BW.  A direct measurement of the
action ratio (6 mm dip causes hammer travel of x?) would be helpful.  As was
mentioned by several contributors, friction readings need not be a mystery
and can easily be ascertained by a survey of the UW and DW through the
keyboard.   Remaking the keys certainly would solve any questions and
problems but it¹s not in the cards for this job.  Still, having redone many
of these actions without remaking keys there are always solutions.  But
without the data it¹s difficult to know the limits of what is achievable and
the best way to get there.
 
David Love
www.davidlovepianos.com
 

From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Brent
Fischer
Sent: Wednesday, August 25, 2010 6:58 AM
To: caut at ptg.org
Subject: Re: [CAUT] Down Weight Too High With New Hammers
 
 
     
    
  Hey guys, 
    
     David, I know it is counter-productive to increase
  interia by moving leads to the front. We know Steinway
  fit the action to the strike line therefore moving the
  capstans away from the theoretically correct position.
  Hamburg fits the piano to the action which is why
  I've seen so many prefer it over NY. I am interested
  in your solution given Paul's constraints. I believe
  the original knuckle dimension is around 15.5 mm?
  I found this always increased dip when going longer
  however am not an action designer, but have had Roseland
  Piano re-manufacture several of this vintage keyboards
  with corrected ratios and it was the answer to being
  able to lead closer to the balance rail with great results.
  
 


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