aftertouch / hammer striking distance

[piannaman at aol.com]

 Hey Andre,
 
Good to see you back on this list!  It inspires me to go and decrease the keydip on my piano (I've needed to do it anyway).
 
Cheers,
 
Dave Stahl

 
 
-----Original Message-----
From: concertpianoservice at planet.nl
To: ed440 at mindspring.com; pianotech at ptg.org
Sent: Fri, 26 Jan 2007 5:39 PM
Subject: Re: aftertouch / hammer striking distance


There was a time in my professional life where I had a complete break through.
It was when I learned that a hammer travel distance gauge is not necessary anymore.
At the time, I was working for Yamaha in the Benelux and they had just gotten a brand new concert grand, the handmade CFIII-S.
This instrument was used as a demo and it travelled from here to there etc.
A couple of times it was loaned to Yamaha France, and every time it came back, I noticed that someone had changed the hammer striking distance.
Later I found out from a Japanese Yamaha tech why and how it had been changed and I will tell you about it here.
At the concert grand level, regulating the 'final' hammer striking distance is one of the last procedures during regulating.
After a hammer change, the hammer striking distance is regulated in a rough and so so way, only to make it workable during the regulation.
The final striking distance is the last procedure in regulation and it is in immediate connection with after touch.
When a grand regulation has been completed, the hammer striking distance is defined by the amount of after touch.
At the Yamaha Academy they teach that a perfect after touch is when one depresses the key, one goes through the motion of let off and drop, the key then rests on the front punching, and if one presses lightly, there should be a slight hammer movement of 0,4 mm.
The 0,4 mm is a healthy average movement.
It ensures an 'extra' after let off and drop have taken place, so that the jack can easily escape from under the knuckle, and especially during ppp, always a danger zone.
The 0,4 mm is a very tiny distance, but it is enough and it also creates a certain 'touch', a certain feeling.
It is safe and comfortable. However, because the movement is 'extra', it is also a little bit of a waste. A waste in movement, a waste in time, and thus a waste in energy, but, nevertheless, it is comfortable and, when executed correctly, always gives the technician a maximum of power.


Some pianists demand a smaller after touch or hardly any after touch at all.
This is highly dangerous for soft play and it is only possible with a perfect action with maximum anti friction treatment.
Some pianists demand a larger after touch, but that's stupid and literally a total waste.
They usually don't know what they are talking about.


Of course the after touch is mainly defined by the elasticity and hardness of the front punching but that is an other chapter, and an old story I will not get into again. (for more info go into the pianotech archives)


OOR


On 26-jan-2007, at 12:05, ed440 at mindspring.com wrote:


Ed Miller-


1/8" jack escapement is too much.  1/16" is plenty.


Check for lost motion. Excess lost motion is often just enough to steal your aftertouch.


Use a checking distance gauge as Cy Shuster recommends.  Bend a coat hanger wire to 5/8" or mount a section of 5/8" dowel on a stick.


Worn hammers or flat hammer butts may make it impossible to get a good regulation.


If you are studying for the RPT exams, you can post questions like this to the ExamPrep list (see members' section of ptg.org)


Ed Sutton


-----Original Message-----
From: ed miller <edmiller3 at hotmail.com>
Sent: Jan 25, 2007 8:42 PM
To: pianotech at ptg.org
Subject: aftertouch vs jack escapement


I'm regulating a Knabe upright. I’m having a problem juggling acceptable 
aftertouch vs. an acceptable amount of jack escapement out from under the 
hammer butt.


With blow distance set at 1.75", let-off at 1/8", key dip at 3/8" and 
checking at 5/8".... aftertouch is about .040". With the dimensions as such 
the key feels like it plays well. In previous regulations I would have been 
very happy with this.


However, this time I'm regulating according to Bill Spurlock's Vertical 
regulation pamphlet. In it he talks about aiming to have jack escapement be 
1/16-1/8" out from under the hammer butt when the key is fully depressed. 
With all of the above dimensions in this Knabe upright the jack doesn't 
rotate completely out from under the hammer butt.


Spurlock suggests decreasing the hammer blow distance to allow the jack to 
escape further. When I do this my aftertouch becomes too great. If rather, I 
increase the key dip to allow for more jack escapement aftertouch becomes 
too great again.


In order to have the jack escape properly I would have to decrease the 
hammer blow distance to under 1.5” (I know because I tried it). As I 
suspected my aftertouch shot up, it was then .100”. If I then decrease key 
dip, the jack doesn’t rotate far enough.


Then I tried to make my checking earlier. Even at less then .5” checking the 
jack doesn’t completely get out of the hammer butts way before it is caught.


What do I do????


Thanks, Ed


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friendly greetings
from
André Oorebeek


Antoni van leeuwenhoekweg 15
1401 VW Bussum
the Netherlands


tel : 0031 35 6975840
tel : 0031 652388 008


concertpianoservice at planet.nl
www.concertpianoservice.nl


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