action centers - correct friction?

[John Formsma]

Don,
Thanks for your much-valued input.

-- 
JF

On Wed, Oct 8, 2008 at 7:14 PM, Don Mannino <donmannino at ca.rr.com> wrote:

>  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 <formsma at gmail.com>
> *To:* Pianotech List <pianotech at ptg.org>
> *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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