[pianotech] U3 hammer flange string / fiber

[Tom Driscoll]

My post from the archives : 
>              
> From the archives with editing:
> I've done many of these jobs and have posted a method for
> > Replacement of the cords in the past. With input from a tech in Japan, 
> > (Sorry, but his name escapes me now) I refined my approach so at the 
> > risk of some redundancy here goes. First, we are assuming that the 
> > pinning is solid, the flanges are well traveled, and the hammers are
> not
> > worn past reshaping. These pianos are usually less than 20 years old
> and
> > If not in a school situation, I've found them to meet these criteria. 
> > With the action in the piano I space hammers tightening the hammer
> flange screws. 
>       Now with the action on the bench and in the cradle,I  tighten all 
> remaining screws, reshape hammers
> > and blow out all debris.
>       Remove the hammer rest rail--easily done in
> > this action by unscrewing the hangers from the rail. Next Loosen the 
> > butt plate screws and hang the whole butt-hammer assembly from the 
> > bridle straps without disconnecting them from the bridle wire. (That
> was
> > the tip from our Japanese friend) Now the flanges are exposed for 
> > removing and replacing the cords. I put a small amount of acetone on 
> > the slots and then immediately clean out the old cord and slot with 
> > the chisel point of a small spade drill bit. ( By hand -not chucked in 
> > the drill!)  You may have to reapply the solvent as you go. Finish the 
> > slot cleanout with a small brass suede brush, and
> compressed air or vac.
>       (I found that the action centers are unchanged by any acetone that 
> migrates to the bushing)
> >     Now for the cords. If this is not a gray market piano you can get the 
> > cord from Yamaha wrapped around a small cardboard tube. If not 
> > available wrap some silk cord ( avail. From Schaff) around an old #88 
> > key top and slice down the middle. Either way works, but the idea is
> to get 88
> > cords cut to exact length. Now glue one side in the slot -I use
> > titebond- a small amount -and press the cord in the slot with a small 
> > screw driver lining up the end of the cord with the line in the
> flange.
> > By the time you get all 88 done the glue will be set. Go back and glue 
> > the other side. Reinstall the hammer-butt assemblies, put the springs
> in
> > the cords, reinstall the rest rail and your done. Two hours max and 
> > less with practice.
> >     The advantage over replacing the flanges is not only time, but
> > it is difficult to travel the new flanges with the dampers in the way.
> > hammer spacing will not change, the old flanges are already
> > Dimensionally stable @ the screw and will not need retightening as
> > soon. 
> >     If this is a worn action with loose pinning then flange
> > replacement is the best way. Also if this is an action without butt
> > plates and the flange is pinned to the butt in my opinion it's less
> > clear which method is best. I've done about quite a few of these and
> > almost all have the butt plate style.  
> >     ` Tom Driscoll
> > 
----- Original Message ----- 
  From: Ryan Sowers 
  To: pianotech at ptg.org 
  Sent: Sunday, March 22, 2009 1:42 PM
  Subject: Re: [pianotech] U3 hammer flange string / fiber


  If the butts have a plate, it works out pretty well to replace the loops. There is a great description of this repair in the archives somewhere. You don't even have to remove the bridle tapes. Maybe someone can provide a link to the detailed instructions. I searched a little bit but was not having much luck. Its worth finding!


  On Sun, Mar 22, 2009 at 9:12 AM, Joe And Penny Goss <imatunr at srvinet.com> wrote:

    "Spider Wire" from your local fishing shop
    Joe Goss RPT
    Mother Goose Tools
    imatunr at srvinet.com
    www.mothergoosetools.com
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