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

[gordon stelter]

Hi Jeannie,
    I WILL call the Yamaha factory...... but to report
what I consider a design flaw, or flaws!
    Specifically, the front jack tip has too sharp an
edge, the butt buckskin seems a bit too thick and
"fluffy", and the angle on the butt face is too acute
in its transition between its 2 planes. 
    Together ( and in particular the jack tip shape
)these seem to be conspiring to prevent the jack from
tripping out from under the butt. On this nearly new
piano, the letoff was obviously human-adjusted at
ridiculous and varying widths ( 5 mm to 10 mm ) to get
the jacks to trip at all!  But now that a little wear
and compression has set in, many butts are bouncing on
their untripped jacks, again.
     I got the Yamaha factory specs from a Yamaha
trained tech at my local Bosendofer store. The keydip
and hammerstroke are at spec already, so it is
apparent to me that if I set the letoff at the 1.5 to
3mm Yamaha recommends, almost ALL the hammers will
bobble!
     I thank the techs who have responded to my
inquiry. I will bring their letters to the music
minister to see if he wants to pursue this as a
warranty issue.
    Thanks Again!
    Gordon

P.S. I have 30 years' professional experience
repairing pianos. As the too wide let-off on this
piano ALSO exists on notes 1 and 88, which show no
sign of being played, I can only assume that this
"adjustment" was introduced in the factory in an
attempt to overcome the pre-existing problem as
described above.


	
		
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