help with action geometry

[Ed Sutton]

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Wim-
    If I understand your problem right, I believe the height of the =
hammer flange center should be equal to the string height minus the bore =
distance of the hammer.
    To locate the stack front and back, lock the keyframe with no keys =
in place with the cheek blocks, then slide the stack back and forth at =
the previously established height.  Snap the wippens with your finger to =
establish the strike point and mark it.
    Then you will have to check for capstan line and wippen foot =
alignment.  Maybe move the capstans  to improve touchweight.
    I will stand corrected by anyone with more real world experience of =
this than me!
    Good luck.
        Ed S.
  ----- Original Message -----=20
  From: Wimblees@aol.com=20
  To: Pianotech@PTG.org ; caut@ptg.org=20
  Sent: Thursday, February 13, 2003 7:04 PM
  Subject: help with action geometry


  I am in the process of rebuilding a 1895 Model A, which was done once =
before, but very poorly. The first thing I noticed, and the thing the =
customer complained about, was an extremely heavy action. This was =
because there was a lot of let off, about 1/2". When I removed the fall =
board, I noticed that the pin block (which had been replaced), was =
sticking down from the front stretcher about 1/4".  My first inclination =
was that the plate was set back in the piano too high, and that is why =
there was so much let off. =20

  I have replaced the pin block, and the plate is back in the right =
position, and there is good downbearing. But I am now starting to work =
on the action, replacing the h/s/f and wips. Now I see why there was so =
much let off. This other rebuilder used a 1 1/2" thick pin block. But =
instead of planing down the entire block, he only trimmed down the ends, =
which rest on the inner rim, but he left rest of the pin block the =
original 1 1/2". That is why there is about a 1/4" of pin block sticking =
down below the stretcher. Obviously that wouldn't allow the action to =
slide in. So in order to get the action in, he lowered the action by =
shaving down the action frame mounting blocks. (I think that is what =
they are called).=20

  I want to replace the blocks. But the question I have is measurements. =
About 20 years ago when I put a new action in a Steinway, and these =
blocks were not attached to the action frame. I think I remember I had =
to sort of go by where the striking point was of the last couple of =
notes, combined with the hieght of the hammers. I had a hell of time =
figuring out where to put them. Is there some measurement I can go by to =
determine where I have to put the blocks, and how high the action has to =
be?

  Wim=20

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