Riddle Answer (:)}}

[A440A@aol.com]

Greetings all,

Whew!!   There were some close calls on this one,  I started feeling like I
was dodging bullets every time I read my mail!.  As I write this, no one has
mentioned the problem, but I must say that Jim Coleman came closer than
anybody.

Problem:

      Excessive spring pressure was needed to return the jacks,  and even
then excessive height on the balancier was required, and several notes would
skip.
      When the action train was set to the factory nominal specs, there was a
profound loss of repetition.  Only when the spring was set quite strong, and
the mortise was at least .015 above the top of the jack, would the piano
repeat well enough, but it felt terrible!!

Riddle:  What was the repair that made all the difference?

Clues:

1.  A tech did a beautiful job of filing hammers and bolstering the knuckles,
 aside from that and turning the adjustment screws,  nothing else was done
in the action.
2.  The action was all factory original, rails were in the proper place
3.  The repair required two hours and when finished, there was approx. 200%
more rep. spring tension, (hammers flew!)
4.  The spring groove, (grub) was well lubricated

 1.  The key has nothing to do with it
2.  the repetition lever has nothing to do with it
3.  Avery was closer than anybody........{he mentioned jack pinning first)

1.  Action adjustment screws had nothing to do with the problem
2.  The pinning had nothing to do with the problem
3   All whippens were removed for this repair
4.   Nothing was taken, nothing was added

Answer;

        The problem with this action was that the repetition springs were not
bent up  at the end that is inserted into the hole in the jack.  When the
jack was in proper position under the knuckle,  the angle of that hole was
steeper than the approach of the spring, and there was not enough vertical
clearance,   thus putting a bind on the the very end of the spring.

       This felt like stiff pinning, as the jack would not really snap back
in place if released from the midway point.  Jim Coleman knew the feeling,
and a too long spring will often show this exact same problem, however,  I
looked at the lengths, and they were fine.

       The result was that the jack would return under the knuckle if there
was no drag at all, but there was no real force applied, as there was a micro
amount of wood fiber crush going on down below where the spring was bound in
the hole.  Backing out the jack adjustment screw all the way left the jack
"floating" in position, without having contact with the spoon.

      Bending the end of the springs up just a little, with brass jawed
pliars,  solved the problem, and allowed the action to be regulated normally
with fine results.


Thanks for all that responded, I learned a bit myself, just from getting to
follow others investigations.

Regards,
Ed Foote
Precision Piano Works
Nashville, Tn