Vs: bobbling hammers-1993 Kranich&Bach

[Lance Lafargue]

Ron,
If the key is still partially depressed (that's when most of this bobbling
takes place) the jack is out from under the butt and the hammer hits
against it causing the bobble.  If the jack spring is stronger or not, the
jack will still be out and causing the bobble-am I right?  Not sure I
understood you.  Thanks.
Lance Lafargue, RPT
New Orleans Chapter
Covington, LA.
lafargue@iamerica.net

----------
> From: Ron Nossaman <nossaman@SOUTHWIND.NET>
> To: pianotech@ptg.org
> Subject: Re: Vs: bobbling hammers-1993 Kranich&Bach
> Date: Tuesday, February 03, 1998 8:32 AM
> 
> Hi all,
> 
> From what I've observed, the main cause of this seems to be the leverage
> ratio between the jack leg and fly; short leg, long fly. You need a
pretty
> strong jack spring on that short moment arm to get the fly back under the
> butt between keystrokes. This makes for a very quick action, but it
> increases the resistance and affects the feel at letoff. New piano
students,
> particularly, seem to have trouble with this. They tend to stop at the
> letoff resistance instead of stroking through it. Occasionally, I have a
> customer that just can't make peace with this and I have to compromise
the
> regulation somewhat. I will generally lower the letoff rails a bit to
widen
> letoff to about 1/4". I make sure the capstan adjustment is good, and set
> the backchecks a little closer than I normally would. This will usually
get
> me, the piano, and the pianist(s) back into service for the next couple
of
> years. By then, everyone has gotten used to the feel and I can usually
get
> the regulation back to where it belongs with no trouble. In a school
> situation, perhaps a little teflon powder on the butt leather would
lessen
> the drag and improve the situation.
> 
> Might help, might not - hope so.
> 
>   
> 
>  Ron Nossaman
>