Steinway [non-adjustable jack] question

[A440A at aol.com]

<< n how crucial it is to get a good adjustment on
the jack position for good regulation. I was hoping for a procedure that was
more exact than a visual alignment on the section ends, draw a thread across
the section, align the rest of the jacks to the thread.  >>

Two ways, both of which require individual examination of the jack/knuckle: 
   1.  Visually align the jacks so that their distal edge is approx. .5mm 
proximal to the distal edges of the core, (or go ahead and line them up exactly 
if you need the insurance.  it WILL cost you some sensitivity,though) 
    2.  Play the note a F blow, bring the jack closer, play it again, bring 
it closer........ continue on until you feel that there is a loss of power, 
then return the jack just enough to restore the power.  This is a technique that 
requires a lot of experience, (and time).  
    Some actions will function perfectly with the jacks almost aligned with 
the near edge of the core, but that always seemed dangerous to me.  
REgards,  



Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html