bridle strap - was Re: 1902 Conover upright jack lever

[Tony Caught]

Kevin,

In regulating an upright piano I have always adjusted the strap wires to be
firm when the 'soft' pedal is depressed and the key / wippen does not move.
This point will vary from one piano to another but I will suggest that it be
1/3 of the hammers travel to the string.

At this point the hammer will still blubber if the butt return spring is
broken and if you tighten the strap further it will effect the key touch
weight greatly when played with the 'soft' pedal depressed.

I have found that by adjusting the check into a better (and sometimes lower)
position it will stop the blubbering better. The blubbering is of course
caused by a multiple of faults being a combination of one or all of the
following.

Broken return spring or cord, jack not clearing the butt, check not catching
the butt correctly.

Regards

Tony


----- Original Message -----
From: <kam544@flash.net>
To: <pianotech@ptg.org>
Sent: Sunday, June 24, 2001 1:20 AM
Subject: Re: bridle strap - was Re: 1902 Conover upright jack lever


> >...I would think the strap would have to be adjusted somewhat tauter then
> >we do
> >today... or what.. ?
> >Richard Brekne
>
> More good stuff there, Richard.
>
> About the tauter thing:
>
> Just yesterday I went out on a service call for a note that was reported
> inoperative (studio size piano).  The problem was the inability of a
hammer
> to return due to a broken hammer butt spring, so it just rested itself
> against its related music wire.
>
> My first thought, of course, was, "Well, looks like I am going to have to
> replace that butt spring."  No real big deal, really.  But then I noticed
> all this excess play in the bridle strap.  So for the fun of it and an
> obvious short cut, I modified (bent) the bridle wire back sufficiently to
> cause the strap to be "tauter", which then allowed the hammer to start its
> return back home when the key was released.
>
> Now, as a result of this thread, I'm thinking in the case of upright
pianos
> in general, that another serious consideration for the bridle tape concept
> was to insure that the hammer actually returned far enough back past the
> point of perpendicular to its mounting, coupled with overcoming any center
> pin resistance, to enable the hammer return spring to then do its job of
> returning the hammer to its final destination.
>
> Final destination meaning, close enough so the jack lever tip will at
least
> be able to engage the hammer to strike again.  Ironically, that would then
> touch on the premise of aiding faster repetition, or more exactly as I see
> it, allowing the note, for all practical purposes, to be repeated at all.
>
> What fun!
>
> Keith McGavern
> Registered Piano Technician
> Oklahoma Chapter 731
> Piano Technicians Guild
> USA
>
>