[pianotech] regulation "sweet" spot

[bobdavis88 at aol.com]

 Steven,

Beware of specifications! You should always regulate a few notes completely before you start, to find out if your "specs" actually work with that action. On a slow blow, after the jack releases, the hammer will fall back slightly, at which point there should be additional key travel of maybe .040". During this "aftertouch", the hammer will then rise again on the rep lever to its final destination.  You might have to compromise either the blow or the dip in order to get correct function; it depends upon the exact leverage of all the parts.

I'm
wondering why you say the regulating button is all the way down. Your letoff could be early. When the key is slowly depressed, the heel of
the jack should contact the regulating button at about the same time as
the repetition lever contacts the drop screw, or just barely after. A low button would usually indicate that the jack [letoff] is way early or that the
hammers were bored too long (less likely but possible). On a very slow blow, if the jack kicks out
way early, the repetition lever will still carry the hammer on up close
to the string, but there won't be any letoff bump. If on the other hand
the repetition lever contacts too soon, you will have letoff, but there
will be lots of resistance, the hammer will fall a long way, and you
will feel a springy sensation in the key well before the jack kicks
out. 
Bob Davis
 

 

-----Original Message-----
From: Steven Hopp <hoppsmusic at hotmail.com>
To: pianotech at ptg.org
Sent: Tu
e, 20 Jan 2009 6:12 am
Subject: [pianotech] regulation "sweet" spot













Hello again,

 

I have installed new hammers on a baldwin grand and am now doing the regulation.  I have followed all recommended steps and things are going smoothly.  (This is my first full grand regulation).  I am having some trouble on a few notes not finding that "sweet" spot of let-off to drop ratio or point.  I am using a let-off rack set to baldwin spec of 1" 7/8" and have levelled the hammers for a proper blow distance.  The majority of the notes are good and behave as expected. i.e. a slow rise of hammer to a 1/16" below string strike with a 1/8" drop with that little bump (what I call the sweet spot) in the feel of the key as you play.  Granted on the good ones some of the "bumps" are stronger than others but on some it is very weak or on the bad notes it is not present at all.  

 

The questions I have are:

 

1.  What should I do when I can not get the two Let off and drop to reconcile?  (good rise vs. too much drop or poor rise with that magic bump in the feel)

 

2.  If I get the regulation button turned so low that there is no more turn left and I am not getting good results what should I do after starting back at beginning of that notes regulation?

 

This action is about 30 years old and to my knowledge has never had any regulation.  Any help or suggested r
eading would be appreciated.  I have all Pace resources and Reblitz but recommended order of regulation is not helping with the reality of regulation problems.

 

Thanks again to all who help so willingly,

 

Steven



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