Story and Clark/QRS console bubbling hammers

[Paul McCloud]

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Hi Dave:

            I fail to see how pressing the damper pedal would affect the
checking of the hammers. 

If you press a key slowly, does the backcheck get close enough to the
hammer butt  to touch it, and (hopefully) to catch it on the rebound?
How far from the string is the hammer when it checks?  Sometimes the
checking distance is too close to the string.  Be sure, also, to adjust
the lost motion.  Too much will prevent the proper checking action, the
same as insufficient dip.  

            The leverages are already set by the design of the action.
It is the travel (movement) of the parts, and the distances involved
that allows the action to do what it is designed to do.  (Assuming the
parts themselves are not damaged, worn out, loose, or stuck).  There are
two things that need to happen for the hammer to check.  The jack must
clear the butt, and the backcheck /whippen /hammer butt need to come
into contact.  

Even if you have aftertouch, still, other things can affect the
checking.  The Mason I was working on had aftertouch, and seemed to play
correctly, but for want of sufficient dip, was not working to its
optimum.  A little more dip made the world of difference.  It is my
experience that the Chinese pianos sometimes aren't regulated to my
liking.  Although they may work, often they need better regulation.
This may entail raising the center rail, leveling keys, shimming the
hammer rail, bending the backcheck wires,  whatever.   

            Let me (us) know if adding more aftertouch (dip or shorter
blow distance) does the trick.  

            Paul McCloud

            San Diego         

 

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Piannaman@aol.com
Sent: Saturday, December 06, 2003 8:54 AM
To: pianotech@ptg.org
Subject: Re: Story and Clark/QRS console bubbling hammers

 

Hi Paul, 

Thanks for the advice.  There is plenty of aftertouch.  That was one of
the first things I checked and corrected, because initially, there was
none.  Everything works fine--until the damper pedal is engaged. 

I will put some thicker punchings on a few balance rail samples and see
if it can be regulated properly before I raise the whole rail.  Could it
be a leverage issue??   


Dave Stahl 



In a message dated 12/6/03 8:29:10 AM Pacific Standard Time,
pmc033@earthlink.net writes: 





           You need to determine if there's enough aftertouch.  As you
go through let-off and the key bottoms out, check to see if there is a
little forward motion of the hammer, and that the jack it out from under
the hammer butt.  If not, your key dip is still too shallow.  Putting a
thinner punching may get you closer to the correct dip, but you need to
be more precise with this adjustment.  Setting the letoff point will
help some, but you must be sure that you have enough dip to make it
work.  I recently worked on a Mason Hamlin large upright which had a
similar problem with bobbling hammers.  Actually it wasn't so much
bobbling, but the piano had a kind of "loose" feel.  By raising the
balance rail, the dip increased and the checking worked much better.
Hope this helps. 
           Paul McCloud 
           San Diego 

 


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