Console Jack Reset Trouble

[Dean May]

I've also done the stretching the jack spring trick to get one or two jacks
to reset. It seems that YCs  and Samicks tend to get weak jack springs as
they get 15+ years old. I'm replacing a set right now off a K&C upright
(made by Samick). Piano is about 20 yrs old.

If the piano was functioning when it was new, the keys did not re-lead
themselves to cause a weight problem (not to say that re-weighting couldn't
bring an improvement). Logically it seems to me that either excess friction
has been introduced or springs have weakened. Friction can come from
jack/whippen centers, or the knuckles, al la the Baldwin artificial stuff.

I've also gotten improved reset by adjusting the backcheck a little closer.

Dean

Dean May             cell 812.239.3359
PianoRebuilders.com   812.235.5272
Terre Haute IN  47802

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On Behalf
Of ryan sowers
Sent: Sunday, July 25, 2004 8:30 PM
To: Pianotech
Subject: Re: Console Jack Reset Trouble

I have experienced this on a number of console actions
including several Seinways. Strengthening the jack
springs by removing them from their upper seats and
carefully stretching  can help. A stronger jack spring
will definately add more downword pressure on the back
of the key.

Two of the three Steinway consoles that I've come
across with this problem had jack springs that were
weak evidenced by the fact that a couple were broken.
Replacing with a new spring caused the wippen to
return to its rest position much more effectively.

In one case the customer was a bit confused because I
was the second opinion. The previous technician had
suggested reweighting the keyboard, whereas I had
recommended replacing all the jack springs. The spring
issue is harder for the customer to visualize than
reweighting. Its a little more abstract.

I feel replacing the springs to be more appropriate.
It appears that Steinway wanted to have the keys be a
bit heavy in front. What do others think?



--- Farrell <mfarrel2@tampabay.rr.com> wrote:
> I serviced a 1980s Young Chang 106 cm (42") console
> today. Lady was complaining about a number of black
> notes that would not play after you played them once
> (would not repeat after playing softly). I inspected
> and sure enough on many of the black notes, when
> played very softly/slowly, the jack would not reset
> back under the hammer butt.
>
> Plenty of lost motion. On white notes that reset,
> some jacks would reset immediately upon starting to
> release the key - the hammer would stay up near the
> string and the jack would reset immediately - on
> other white notes, the jack would reset when the key
> had fully returned (it would rely on there being
> some lost motion).
>
> I eased the black keys (some were tight) and
> weakened the hammer butt springs and that seemed to
> help - but I could still make a few of the notes not
> reset if I worked them very slowly.
>
> I think most of the problem (besides simply being a
> 1980s YC console) is that the black keys all have a
> lead forward of the center rail pin - pattern
> leading. These black keys are very front heavy. Most
> of the white keys are unleaded (and they repeat just
> fine). The white keys require very little weight to
> push the back of the key down - even a console
> wippen could push them down! The black keys require
> much more effort to push the back of the key down.
>
> I think if today's efforts do not meet her needs,
> re-leading is the answer. Piano is not worth a
> Stanwood approach, but maybe drilling some 1/4"
> holes in the black note leads or even removing the
> leads will make the key Front Weight more in line
> with the naturals.
>
> Anyone have any thoughts on this situation or direct
> experience solving a similar problem.
>
> Thanks to any and all of you wonderful Pianotech
> list enthusiasts!
>
> Terry Farrell
>
> www.farrellpiano.com


=====
Ryan Sowers, RPT  Puget Sound Chapter
Pianova Piano Service
Olympia, WA



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