<HTML> <HEAD> <TITLE>Re: flagpoling or killing pin-block?</TITLE> </HEAD> <BODY> <BLOCKQUOTE>My interpretation of the  whole issue of bending of the pi= n is this:  The tuning the pin flexes upwards while one raises the pitc= h whether one realizes it or not.   This is due to the many forces=  acting on the pin during the raising of the pitch.   At res= t there is the string tension pulling downwards on the pin, not only a rotat= ional tension but a vertical tension.  The rotational force (torque) is= balanced by the static friction between the pin block and the pin.  Th= e downward force is balanced by the strength of the elasticity of the  = steel in the tuning pin. The pin IS flexed down  while there is string = tension on it. The tricky part is understanding how the tuning lever is acting on the pin.=  When the string moves during the raising of pitch  the forces ar= e no longer in balance.  At the very least  (if the force of the t= uning hammer is imagined as a person pulling  on another string wrapped= around the pin the other direction) , the rotational  friction between= block and pin and the tension of the string have been overcome.  If th= e string is moving (raising pitch) has the vertical tension  also been = overcome?    The solution is  complicated by the fact th= at the force from the tuning lever is off center because it has one handle. =  Which direction is it being pulled from? Usually the from right but th= e variations in lever and arm position could cause upwards or downwards forc= es to act on the pin. The technicians arm position may also not be in line w= ith the rotation of the pin (though it should be as close as possible) which= is probably why this is more of a vertical piano problem than with a grand.=  Ever try to break a lug nut free with a tire iron and have it come fl= ying off into the ground?  That's because (like the tuning lever) the f= orces are not applied purely as torque or tangentially to the pin.  <BR= > The school of thought of "tweaking " the pin back down into its r= esting position believes that the pin has been relaxed from its flexed posit= ion during the tuning.  A third hand to play the note and a T handled t= uning wrench with the other two hands on it is what we need.  Or a phys= ics (mechanics) major. Sorry for the lengthy diatribe. Jon Rhee Weymouth, MA </BLOCKQUOTE> </BODY> </HTML>