misfiring jack

[Tom Driscoll]

H.  Try a jiffy weight as experiment on the worst offender and check that
touchweight does not become excessive. Spinet players get used to that easy
touch and might object to a weight that seems to be within reason.Check for
tight balance rail holes , key bushings ,and whippen centers first. Good
luck ,Tom Driscoll
----- Original Message -----
From: "H. Pengelly" <pengelly_pensione@telus.net>
To: "pianotech" <pianotech@ptg.org>
Sent: Thursday, December 07, 2000 12:01 AM
Subject: misfiring jack


> Dear list, I recently tuned a Homer upright spinet that had a few
> miss-hitting keys. Upon closer inspection I noticed that the jack wasn't
> slipping back under the hammer butt. The key bushings are fine and the
lost
> motion is set properly and the problem persists. Incidentally the action
is
> miniature and the keys from the balance pin bushing are cut at a slope to
> clear under the wippens. It appears to me that the back of the keys are
too
> light and sit up too high thus preventing the jack to return. If you press
> lightly down on the back of the key then the jack goes back. There are no
> weights in the keys and they are quite front heavy. When the soft pedal is
> depressed the problem is worse. The front of the keys dip as if the bridle
> tapes were too tight but they aren't. The weight of the action seems too
> light  to stop the keys from rising up at the back. In my 16 years of
tuning
> this is a first for me,I know I've been lucky, and it has me perplexed. I
> could probably fix it by adding weights to the keys but it originally
worked
> ok so what are your thoughts? Much appreciated
> John Pengelly
>
>