[pianotech] Bridge agraffes FYI

[Ed Foote]

Our family piano was a 1875 or so Hallet & Davis upright.  It had 
agraffes on the bridge, and they had holes slanted through them. The 
wire would exit the hitchpin side from the low side or high side, since 
every other one was turned so that the bearing was either extremely 
negative or extremely positive.  The soundboard itself was perfectly 
flat.
   sounded pretty good.


Ed Foote RPT
http://www.piano-tuners.org/edfoote/well_tempered_piano.html

-----Original Message-----
From: David Love <davidlovepianos at comcast.net>
To: pianotech <pianotech at ptg.org>
Sent: Thu, Oct 25, 2012 2:57 pm
Subject: [pianotech] Bridge agraffes FYI


   Attached are two photos of a Sohmer Grand bridge with bridge 
agraffes.  Veryinteresting in that the string bears on the top of the 
aggraffe hole, not onthe bottom as one might expect.  In order to 
maintain positive downbearingon the bridge, the bridge has a raised 
shelf behind the aggraffe such thatthe string runs uphill to the bridge 
 from the hitch pin area before runningdownhill to the aggraffe from the 
short span off the front of the shelf.The slope of the string then 
rises as you move toward the tuning pintermination side.  Sadly, I did 
not have my bubble gauge to try anddetermine the net bearing and it's 
definitely got me reaching for the fishoil capsules thinking about 
whether a measurement of the relationshipbetween the hitch segment and 
the front segment would reveal the net bearinganyway.  The piano 
sounded like caca, btw, but there were other issues.  Inspite of that, 
the tone was surprisingly focused.  David Love