Butt Flange Cord and Spring Repair

[J Patrick Draine]

Garret, There's plenty in the archives in answer to your question. Below I
have copied one of protocols:

*Yamaha vertical flange cord replacement procedure*

* *

Decide if repining is in order before removing hammers from rail.

Check hammer travel and mark the top of the butt with chalk for which side
to apply paper on reassembly.



Apply a CLP to the bridle wire ends and remove the straps. Remove the hammer
rest rail treble pivot arm

and remove the rest rail. Remove the hammers/flanges, number each and
separate.

Be careful not to press down on the wippens causing the damper spoon to
bend.



File the hammers on an oscillating spindle or drum sander. Optional: taper
hammers.



44mm cord length: wrap the cord around a dowel or piece of cardboard of a
dimension to get 44mm

when the cord is sliced along the length.



Secure each flange in a vise to clean the grooves (a hacksaw blade works
well), do the set.

Glue cord end onto one side of the flange 10mm; entire set. The glue will be
set to install

the other side from the beginning. Use PVC-E or some other white glue.



Before the flanges are reconnected it's a good time to apply Teflon powder
to the butts in groupings.



Reassemble butts and flanges, install on action rail with travel paper as
marked,

install hammer rest rail, reconnect bridle straps. Wipe off any chalk marks
with dampened cloth.



Spring tension: 40 grams measured at the spring is roughly equivalent to 20
grams measured at the flange.

The angle between the arms is around 90 degrees.



Another procedure can be found here: (see photo at end):

https://www.moypiano.com/ptg/pianotech.php/2006-December/198869.html
On Tue, Jul 15, 2008 at 12:29 PM, Garret Traylor <hpp at highpointpiano.com>
wrote:

>  Hey any of you Authors,
>
> In all my years I have never done this procedure.  What is your take on
> "How to replace Butt Flange Cord and Butt Spring"
>
>
>
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