[pianotech] Weighing Off A Schafer Grand

[Dean May]

Exactly. If you notice the numbers improve dramatically after doing only
item B. Easy to do, keeps the cost down, average customer is very happy. 

 

Thanks for posting this Jon. Very instructive. 

 

Dean

Dean W May                (812) 235-5272

PianoRebuilders.com    (888) DEAN-MAY

Terre Haute IN 47802

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of wimblees at aol.com
Sent: Saturday, January 30, 2010 5:39 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Weighing Off A Schafer Grand

 

Jon

 

Perhaps a combination of the two will make enough of difference to satisfy
the customer. 

What you're proposing, although very impressive and I am sure got the
results you were after, is what I would consider a major reconfiguration of
the action, which might be justified on a top quality grand, but not on an
the piano Patrick has. 

 

Perhaps it is the only solution for this piano, but it is just not worth it.
The customer would be better off buying another piano. 

Just my 2 cents worth

 

Wim

 

-----Original Message-----
From: Jon Page <jonpage at comcast.net>
To: pianotech at ptg.org
Sent: Sat, Jan 30, 2010 2:50 am
Subject: Re: [pianotech] Weighing Off A Schafer Grand

Moving the wippen rail will have marginal effect on BW. Check into
relocating

the entire stack back. If there is ample room between the keys and the
keyslip,

there is the option to move the stack back and the whole action forwards to

maintain the strike point.

 

A few years ago, I had to remanufacture an action which involved lightening
the

hammers, moving the knuckle, moving the stack and removing lead. The problem

was a heavy action with excessive after touch.

 

Here's the results on middle C:

 

a. original survey
b. Reshape hammers/taper/re-arc tails, graduate weight
c. move knuckles out 1mm on shank to 18.5mm
d. move stack back 3mm
e. alter FW to target 38 BW

Survey of C4
    UW  DW  BW  F   SW   FW  SBR
a  32   60    46  14  10.9  32    6.4
b  26   52    39  13    9.9  32    6.3
c  24   44    34  10    9.9  32    5.8
d  22   38    30   8     9.9  32    5.4

e  30   46    38   8     9.9  24    5.4

 

Even after relocating the knuckle further from the center pin, the jack was
still

being buried into the stop cushion. So in order to maintain a 10 mm key dip,

I relocated the stack. KR was in a nominal range and did not require
alteration.

Moving the stack is much easier than relocating capstans.

-- 


Regards,

Jon Page

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