aftertouch / hammer striking distance

[ed440 at mindspring.com]

This is good information, but the question was about a Knabe upright piano, not a Yamaha Concert Grand. This method won't work on a vertical piano.
Ed S.

-----Original Message-----
>From: Concert Piano Service <concertpianoservice at planet.nl>
>Sent: Jan 26, 2007 8:39 PM
>To: ed440 at mindspring.com, Pianotech List <pianotech at ptg.org>
>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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>>
>>
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