"Bobbling" hammers on a new Yamaha U3. ( Please help! )

[Cy Shuster]

I had the same problem with my 1982 U1.  I had broken hammer spring cords,
fixed them, and still had the problem.  It's on soft play, especially when
your fingers move up the tail of the key (as in "Moonlight Sonata", where
you're in C minor, and don't have much choice of where to play the E).  I've
shimmed the balance rail to no help.  Key dip is right.

It's just some notes in the middle.  I wonder if it's a warped key bed or
something like that?

--Cy Shuster--
Rochester, MN

----- Original Message ----- 
From: "pianolover 88" <pianolover88@hotmail.com>
To: <pianotech@ptg.org>
Sent: Tuesday, April 13, 2004 12:20 PM
Subject: Re: "Bobbling" hammers on a new Yamaha U3. ( Please help! )


> Of course, the U3 you're working with is apparently new, but I encountered
> the same "Multi" striking problem on a U3; but it was about 30 years
older.
> The reason: Broken hammer butt spring cords, in addition to needing many
> points of regulation, including backchecks too far from catchers. But then
> again, sometimes the hammer butt spring simply gets disengaged from the
> cord, causing bubbling.
>
> Terry Peterson