[pianotech] Problems with regulating???!!!

[David Nereson]

----- Original Message ----- 
From: "Joseph Garrett" <joegarrett at earthlink.net>
To: "pianotech" <pianotech at ptg.org>
Sent: Wednesday, December 02, 2009 9:47 AM
Subject: [pianotech] Problems with regulating???!!!


> Matthew Todd  asked: "I have been regulating a Baldwin M Grand 
> this morning.
> ?
> Have run into several issues to which I would covet your 
> assistance.
> ?
> 1.)? Exactly how much rise is adequate?

    The hammer should rise "positively" (not sluggishly or 
lackadaisically) but shouldn't "snap" up and "dance" or bounce. 
It shouldn't rise so energetically that it hits the string. 
Enough rise to allow the jack to get back under the knuckle is 
adequate, I believe.

> 2.)? I am having a heck of a time regulating the sharps.? The 
> naturals are coming along fine (i.e. let-off, drop, rise).? 
> The sharps are only 3/8'' high as opposed to the specs of 
> 1/2''.? Could that be the problem??

Yes, they should be more like 7/16" or even 1/2" above the 
naturals.

And if so, and increasing the height to 1/2'', how would that 
affect the dip?

    It would of course increase the dip.  You want the key 
height high enough that you can get 3/8" dip,  but not so high 
that the key pins are protruding less than 3/16" up into the key 
mortises, or that the keys hit the upstop felt on the bottom of 
the fallboard, if there is any, or that the bottom front edges 
of the keys are exposed above the keyslip.
    Then, (assuming the action is bedded), you want the dip such 
that it raises all the keys, naturals and sharps, an equal 
amount at the capstan screws, so that all the wippens travel the 
same distance.
    --David Nereson, RPT

> ?
> Before messing with all the sharp heights, I thought I would 
> get suggestions first.
> ?
> Thank you!
>
> Matthew,
> You have  just described a neophytes approach to regulating! 
> Sheesh! There are  several  factors that have to be  satisfied 
> before  one should  attempt "Regulation"
> 1.  The  action  must  be in good mechanical condition...i.e. 
> gram  resistance in parts  must  be  somewheere in the ball 
> park
> 2.  If the  keys aren't right nothing  else  can be. i.e. 
> keys  at  proper  height and  dip...ALL  of the keys!!!!  key 
> pins  straightened and  polished and lubed. Good bushings and 
> frame felt.
> That's the short version.
> Joe
>
>
> Joe Garrett, R.P.T. (Oregon)
> Captain, Tool Police
> Squares R I