Seating strings

[David Love]

In my experience, the only time strings climb pins is when there is a
notch carved in the bridge pin from the friction of the string over
time.  Then the string will want to seat itself in the notch in the pin.
As the bridge is indented from friction (and/or string tapping) the
notch on the bridge pin no longer aligns itself with the string being
seated on the bridge top and it can appear that the string is "climbing"
the pin.  Tapping down the string in such cases tends to be a temporary
measure as the string will want to seat itself in the groove cut into
the bridge pin.  Otherwise, Ron is correct, the bearing combined with
the bridge pin angles will keep the string seated firmly on the bridge.

Belief is the wound that knowledge heals.  

David Love
davidlovepianos@comcast.net 

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Ric Brekne
Sent: Thursday, April 14, 2005 4:10 PM
To: pianotech
Subject: Seating strings

Hi folks.

We've been through this one many times. It seems perfectly obvious to 
me, and has for about 6 years now since I first heard this << strings 
dont climb the pins >> claim, that for whatever reasons, the strings do 
indeed and in the face of positive downbearing, find themselves on 
frequent occasion up the pins and away from the bridge just a tad.  You 
can measure the conditon of downbearing, make sure there is positve crow

and still find strings not seated.  The fact that it is difficult to 
understand how this can be does change this fact.  Indeed, the lack of 
an explanation for any phenomena says only <<we do not understand>>.  It

is in itself not an arguement for or against anything.

Just measure downbearing, crown, and whatever else you can think of on 
the occasion you find yourself in a string seating situation. I have and

most often when I find strings needing seating, I find positive 
downbearing a plenty.  The report of Don's video does not suprise me in 
the slightest, I'd love to see it.

Cheers
RicB


>/ I just saw a presentation by Don Mannino in Syracuse, NY which
included some
/>/ high tech films of pianos in action.  One film was of a string
moving up &
/>/ down at the bridge and it sure looked like that string might creep
up the
/>/ pin after awhile, great presentation if you get a chance to see it.
/>/ 
/>/ Rob E.
/
Against positive downbearing, against a string offset angle, and pin 
inclination, how is it physically possible for a string to climb, 
creep, or otherwise get up a pin so it is no longer in contact with 
the bridge cap, and stay there? I don't buy it. I'd like to see 
anyone take a reasonably normal piano and make a string stay up a 
pair of bridge pins without touching the cap. Most everyone seems to 
take it on faith that this happens naturally and ubiquitously, but 
no one seems able or willing to demonstrate that it is indeed 
possible by doing it, and proving it by sliding something under the 
string between bridge pins.

Ron N


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