Yamaha U1 regulation problem

[Dave Nereson]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment

  ----- Original Message -----=20
  From: Tom Driscoll=20
  To: pianotech@ptg.org=20
  Sent: Thursday, March 06, 2003 10:06 PM
  Subject: Yamaha U1 regulation problem


  List

              I recently serviced a U1 vertical for a first time client. =
Excellent piano very little wear and -tuned up quite well.=20

              I did however find lettoff to be over !/4 =93and =
inconsistent.=20

              I adjusted to 1/8=94 =96and 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=97(sorry, I forget Y=92s 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 =20

              I know bobbling hammers can be a problem on Yamaha =
verticals and I=92ve worked on hundreds of these, but I can=92t shorten =
blow any more and as I mentioned, keydip-aftertouch are correct. I=92m =
hesitant to increase lettoff back to its original excessive amount, so =
esteemed colleagues ---Any suggestions? I=92m going back next week.=20

              P.S.  Backchecks are also adjusted---I.E. catchers are not =
bouncing out or off of the backchecks

              Tom Driscoll



      I also encountered bobbling hammers on many Yamaha verticals =
during my eight years with a Yamaha dealer.   One of the most common =
responses from Buena Park when I asked for technical help was to tell =
the customers to press the keys all the way to the bottom with no =
hesitation mid-stroke.  [Almost any vertical can be made to bobble by =
hesitating mid-stroke].  Your client's light touch might at times be =
"hesitating" enough on certain blows to cause bobbling.  But I realize =
telling people they're playing "wrong" is a delicate situation.  The =
only other thing the tech. folks at Yamaha would suggest was to check =
the pinning and the spring strength.  I think too tight a center pin can =
contribute to bobbling as well as too weak a hammer return spring (the =
Schwander type springs are considerably lighter than the traditional =
long ones mounted on a separate spring rail).  [A side note not really =
having to do with this problem:  The let-off on the pianos with the =
Silent Piano feature is 1/4" or wider, I believe, and supposedly the =
touch doesn't suffer.  Haven't played one enough to know, though.]

          --Dave Nereson, RPT, Denver

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/6d/fa/46/80/attachment.htm

---------------------- multipart/alternative attachment--