New action and touchweight issues

[Greg W.]

Hello Folks,
   
  I’m not a piano technician
just an amateur pianist, so try to bear with me on technical discrepancies concerning action rebuilding and regulation.   
   
  I wish I knew about this forum prior to my rebuild, since there is a wealth of information here!  Hindsight tells me I could have taken a different approach to this project, but I don’t think all is lost.
   
  My piano is an 1890 Pleyel studio grand piano in excellent shape.   It’s low-tensioned scaled, and is parallel strung.
   
  I’ve installed a new action, and I have touchweight problems.  I get a lot of fatigue after playing for more than half an hour.
   
  The parts I’ve used are Abel Hammers, Tokawa shanks and flanges, and Mason & Hamlin “Miracle” Wippens.  I’ve installed a new action frame, hammer rail, wippen rail, front rail punchings, and new capstan screws to accommodate the new action.  The capstan screws have been relocated from their original position, and are now 3/8” further from the balance rail to achieve sufficient key-dip and clearance for the new wippens.  I left the original key bushings and backchecks, since they are in excellent condition.
   
  My measured average action ratio is 6.28 with a key dip of 3/8”.  I am getting average down weights from 52 grams in the lower register, slowly tapering to 49 grams in the upper register. Up weights are in the 26-30 gram range – friction is from 12 to 17 grams.  HOWEVER - these are the results after adjusting the wippen assist springs, which I have cranked in almost all of the way in order to get the weights this low.  If I disconnect the springs, the averages go from 84-88 down weight and 61-66 up weight...DW is low to mid 70's in the upper register. I've since learned that these springs are only designed to even out touchweight
not to reduce weight from inefficient leverage issues.
   
  I’ve noticed a little “bounciness” at the last 1/8” of the keystroke in soft and slow playing.  I’m assuming it’s still there when playing fast and at higher dynamics.  It's as if there is excess letoff resistance.  My assumption is that this is caused by having the assist springs at high tension, and not too much tension on the repetition springs.
   
  There is some key-leading present (see enclosed photos), but I don’t know if this is considered a conservative amount.  Obviously the original wippens, shanks and hammers were of much lower mass than the new action parts, so maybe more leads are needed with my new action.  My concern was getting the inertia levels too high by adding more lead to the keys.  I’ve been told by others that the leading present is considered minimal, which was typical setup in these old French pianos.  The problem is I don’t know what is considered too much or too little leading.
   
  I’m not certain if the action geometry could be improved, since it appears that the “magic line” is achieved by how I have everything mounted, but I could be missing important details concerning optimum alignment and action spread as evidenced by my extreme downweights.  
   
  I plan on either moving the capstans back toward the balance rail, and/or adding more leads.  The wippen heals can be relocated fore and aft approximately ½” if I so desire to move the capstans.  I hope they will come loose with a fine aperture heat-gun attachment, since I attached them with TiteBond.  I suppose I’ll loose keydip by moving the capstans, but maybe I can live with this.
   
  I’ve also considered removing weight by tapering the hammers with Spurlock’s fixtures, but I’d like to avoid this extra work redoing the job (and messing up my beautiful hammerline!).  I’m also concerned that I’d radically change the tone of the piano by hammer reshaping – the tone is excellent and desirable as is.  Although maybe this won’t be the case, I don’t have experience here.
   
  Any suggestions are appreciated.  I'm sure an experienced rebuilder-tech could take a Gestalt look at this thing and diagnose the trouble, but I can't find anybody in my area to hire for correcting the problems or simple advice.  Everybody tech says they are booked up or too busy otherwise, but I'm probably scaring them away when I tell them I've replaced the action, and they fear working on a hodgepodge hack job!
   
  Greg
   
   

       
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