Yamaha U1 regulation problem

[Isaac OLEG]

The hammers need to drop (a little as for a grand), if they don't
clearly the jack is not leaving the leather enough.

I'd add enough lost motion to help, but not enought to be felt as lost
motion. Tap lightly on the key with the handle of the tool to reset
the jack and test by feel/looking at the jack's move against leather.
I suspect the proble comes from the rebound of the key on the key rest
felt that is bouncy.

The touch (and the tone) is very fair with the largest lost motion
accepted, you have to stay consistent in the sensation, so it may be
adviseable to check with a very light touch the sensation of the jack
contact.

Then the action is free to reapeat at any speed. Letoff may be larger
too (-particularely if a muffler is present).

When you play frankly the notes if the action is working smooth that
can be heard in the tone. If not enough lost motion, more attack but
constrained tone too (thin).

Use the catchers to regulate the strenght of the tone.

Hope that helps


 need to

Isaac OLEG

Entretien et réparation de pianos.

PianoTech
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94400 VITRY sur SEINE
FRANCE
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> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de pianolover 88
> Envoyé : vendredi 7 mars 2003 19:04
> À : pianotech@ptg.org
> Objet : Re: Yamaha U1 regulation problem
>
>
> letoff too close, or CHECK for broken hammer butt spring loops!!!
>
>
>
> Terry Peterson
>
>
>
>
> ----Original Message Follows----
> From: "Tom Driscoll" <tomtuner@attbi.com>
> Reply-To: Pianotech <pianotech@ptg.org>
> To: <pianotech@ptg.org>
> Subject: Yamaha U1 regulation problem
> Date: Fri, 7 Mar 2003 00:06:50 -0500
>
> List
>
>              I recently serviced a U1 vertical for a first
> time client.
> Excellent piano very little wear and -tuned up quite well.
>
>              I did however find lettoff to be over !/4 "and
> inconsistent.
>
>
>              I adjusted to 1/8" -and took up lost motion. Tightened
> action screws. The key dip and after touch were sufficient, and the
> jacks are free to travel away from the butts---no
> interference from that
> adjustable rail-(sorry, I forget Y's nomenclature on that component)
>
>              My client has a light touch and the action
> still stutters
>
> I returned, shortened blow distance readjusted lost motion,
> and adjusted
> spoons to re-correct damper timing.
>
>              My client called again with the same problem and called
> other technicians for advice also
>
>              I know bobbling hammers can be a problem on
> Yamaha verticals
> and I've worked on hundreds of these, but I can't shorten
> blow any more
> and as I mentioned, keydip-aftertouch are correct. I'm hesitant to
> increase lettoff back to its original excessive amount, so esteemed
> colleagues ---Any suggestions? I'm going back next week.
>
>              P.S.  Backchecks are also adjusted---I.E.
> catchers are not
> bouncing out or off of the backchecks
>
>              Tom Driscoll RPT
>
>
>
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