Yamaha Jack issue

[John Formsma]

On Fri, Mar 21, 2008 at 8:45 PM, Scott Jackson <
scottwaynejackson at hotmail.com> wrote:

 Yes! That's the number one problem that i've had with Yamaha upright jacks.
> They can become "wedged" up between the hammer butt and the set-off rail. I
> wasted a lot of time on this when i first encountered it. I couldn't figure
> which direction to move the rail.
>

<G>

It's the amount of time I spent trying to diagnose that particular problem
that has firmly ensconced it in my memory.

Mine was a brand new Kawai vertical.  I changed the regulation a couple
times on one of the bad notes, measured friction on every part (there was a
tight hammer center, but that didn't solve it).  Finally called Kawai, and
they suggested the jack binding on the letoff rail.  It looked like it had
enough clearance, too.  I was, like Terry P., thinking the problem was in
the plastic jack.  Even tried some Teflon powder on the hammer butt.  All to
no avail, because the real problem was elsewhere.

--
JF




>
>
> ... make sure the jack is not being forced into the letoff rail, and held
> there when in check.  At the end of the jack's arc, there should be a
> minimum of 1mm clearance between the jack and the letoff rail felt.  It
> might look like there is enough clearance, so examine carefully.  If there
> is not enough clearance, you need to move the leftoff rail back to you
> slightly (away from the strings).  If you move the letoff rail, you'll need
> to reset letoff.
>
> --
> JF
>
>
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