Reinstalling action stack? (follow-up)

[Keith McGavern]

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At 12:46 PM -0500 5/27/03, Keith McGavern wrote:
>At 12:07 PM -0500 5/27/03, Cy Shuster wrote:
>>... there was a comment that the action should be reinstalled with 
>>the screws to the top of the stack loosened, to be tightened after 
>>the action's back in place, seated on the keybed.
>>  ... Should I follow this same procedure when I reinstall the stack?
>
>I remember reading that and was puzzled myself for doing such a 
>thing at all. Perhaps whoever wrote that could repost their reasons 
>for saying such a thing.

Cy,

Here's the comments of that post, Cy, and the reasons for doing it.* 
It was sent by Avery Todd to Pianotech. It was a post he had on file 
from a person named Brian De Tar, once employed by the Yamaha Company.

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... ON ALL OTHER NON-PLAYER GRANDS:
1. Remove fallboard, cheekblocks, and keyslip.  Same way we always do!
2. Slide the action out far enough to gain access to the action bracket screws.
3. Loosen the action bracket screws approximately 1/4 turn.  Loosen 
the angled screws on the front center action brackets FIRST, and then 
loosen the remaining action bracket screws.  Listen for a little 
"click" when you loosen these screws.  This verifies that the 
keyframe has expanded or contracted a bit from changes in humidity, 
or was not on the keybed (or other "flat" surface) when the action 
bracket screws were tightened.  By loosening and then later, 
tightening these screws in the piano, we eliminate any "flex" or 
tension between the keyframe and action stack. ...

For complete text go to
https://www.moypiano.com/ptg/pianotech.php/2003-May/135358.html
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*Please keep in mind this information is specific related to Yamaha 
grands and that there is no reference to removing the keyarms 
whatsoever for the bedding process in these instructions.

So it would not be applicable to the questions you had, since the 
keyarms are being removed with the action stack being temporarily 
replaced for the purpose of bedding the glides.

Also, shimming any space under the action feet when the screws are 
removed eliminates the possibility of introducing flex into the 
keyframe.

That's my take.

Keith McGavern
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