Riddle Anyone?

[Vanderhoofven]

Dear Ed,

I have no idea what this iddle is, but here are some wild guesses:

1.  Perhaps the tops of the jacks all hare a rough lip that catches on the
knuckle as it returns and as it lets-off?

3.  Perhaps the jack is rubbing against the side of the repetition lever
window causing the repitition to be sluggish.

4.  Perhaps the springs for the jacks have all been bent down so far that
they are rubbing against the wippen, causing the problem you mention.

5.  Maybe there is corrosion on top of all of the repetition springs where
the spring contacts the groove?

6.  Perhaps the silk cord that holds the spring to the jack is broken?
(Doesn't sound likely, but this is a wild guess!)


The idea that the tips of all the jacks are coming un-glued and are loose
makes sense to me.  But in that case, the let-off would tend to be too
close, not too far, so I don't think that is it.

This is great!  I love riddles, and I stayed up til after midnight thinking
about this one!

Sincerely,
David

At 06:41 PM 12/3/96 -0500, you wrote:
>Greetings all,
>
>     It was one of those great days,  a fellow tech had called for advice on
>the Yamaha action he was trying to regulate, after he  had spent three days
>trying everything to make it work, and no luck.  He brought it over to my
>shop so we could both figure on it.  I found the problem by the time he came
>back in from the car. (Sadly, not through brilliance, but I had spent some
>time earlier on the identical problem, so knew where to look).
>
>1.  Yamaha G-2,  approx 10 yr. old
>2.  heavily filed hammers, but not at all past usable
>3.  Tefloned and bolstered knuckles, ( he had put several strips of yarn
>through each).
>4.  Pinning was fairly loose, but not wobbly
>5.  all felts,  balancier (repetition lever),  adjustment, drop leather, etc.
> were in good shape
>6.  graphited surfaces in good condition
>
>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!!
>
>Clues:
>
>1.  He did a beautiful job of filing hammers and bolstering the knuckles,
> aside from that and turning the adjustment screws, he had done nothing else
>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
>
>
>
>Riddle:  What was the repair that made all the difference?
>
>Oh yeah,  it is a church piano....
>
>If the list doesn't care for this type of quiz, lemme know.
>
>
>
>Ed Foote
>Precision Piano Works
>Nashville, Tn
>
>
>

David A. Vanderhoofven
Joplin, Missouri, USA
Associate Member, Piano Technicians Guild
e-mail:  dkvander@clandjop.com
web page:  http://www.clandjop.com/~dkvander/
#pianotech page:  http://www.clandjop.com/~dkvander/ircpiano.html