action centers - correct friction?

[Don Mannino]

John,

2 - 3 grams in the wippen centers is not out of line for a Yamaha.  Their bushings are usually pretty firm.  But try one, repin it for slightly firmer fit, and see if the play improves.  Side to side motion from clearance with the birds-eye is not a problem, but spongy give is nice to eliminate as much as is reasonable.

Keep in mind that the wippen center is one of the least important centers in the action.

The rep levers in Yamaha pianos are also usually set in the factory the way you have observed.  You might get better repetition and spring regulation if you pin this for a tighter fit, but will the gain be worth the time?  It might . . . . or it might not.

Don Mannino

  ----- Original Message ----- 
  From: John Formsma 
  To: Pianotech List 
  Sent: Tuesday, October 07, 2008 4:11 PM
  Subject: action centers - correct friction?


  List,


  I am reconditioning (prior to regulation) the action of a 1976 Yamaha G3 grand. The questions I have concern the whippen and balancier action centers vis-a-vis Don Mannino's post below that I found in searching the archives.


  In the section of bass whippens I've disassembled so far, I've noticed most of the whippen flanges are anywhere from 2-3 grams, measured at the screw hole. The balancier measures about 1-2 grams, measured at the drop screw pad.


  Regarding what Don wrote below, and I consider him expert in this, I should repin the loose flanges. However, I wanted to ask the list before I jump into this. Is there any reason not to repin these centers that I am just unaware of? Does Yamaha perhaps have a different standard for their balancier and whippen flange centers? There is also slight sideward play in the whippen centers, so my initial thinking is they could use repinning. 


  What say you?


  Thanks in advance,


  -- 
  JF



  Written by Don Mannino, 8/11/2007 archived at https://www.moypiano.com/ptg/pianotech.php/2007-August/209291.html
Here are my usual guidelines, with notes.  Gram measurement is made with a
spring gauge at the screw hole, except where noted.


hammer flange centers 

Depends on felt quality and firmness. My usual range would be 2 - 6 grams,
depending on humidity and bushing quality. 2g during dry conditions is OK
with good bushings, but will give poor tone with spongy bushings.  If it's
raining and the bushings are not especially firm feeling, pinning at 6 grams
might be good.  Evenness from note to note is most important in this center.

whippen flange centers 

4 - 6 grams 

balancier center 

4 - 5 grams measured at the drop screw pad (with spring detached, of
course).   This is a very tight feeling bushing when you are testing with
the center pin.
 
Jack should be pinned so that it falls slowly of it's own weight when the
wippen is held with the jack tender pointing up.  This give a correct amount
of friction to match the weight of the upper part of the jack, which helps
control unwanted jack bounces during fast play.
 
Don Mannino

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