---------------------- multipart/alternative attachment In a message dated 5/23/2003 7:25:04 AM Eastern Daylight Time,=20 davner@kaosol.net writes: > We=E2=80=99re not =E2=80=9Cdetermining proper balance rail height=E2=80= =9D, we=E2=80=99re first, bedding=20 > the keyframe =E2=80=93 and, yes, in some pianos the glide studs barely tou= ch, but the=20 > point is to eliminate any knocking of the balance rail against the keybed=20 > when you tap on it. If the rail =E2=80=9Cfloats=E2=80=9D at all, then the= keys don=E2=80=99t have a=20 > solid fulcrum. =20 >=20 > Depending on flatness of keybed, accuracy of keyframe joinery, stiffness o= f=20 > the slats that connect the three keyframe rails, and any distortion the=20 > tightening of the stack down onto the keyframe causes, the balance rail wi= ll sit=20 > at different heights above the keybed in different pianos.=20 >=20 > Second, we=E2=80=99re setting an optimum key height, then leveling keys a= nd setting=20 > key dip. This is done with punchings and assumes the balance rail is=20 > already bedded. I know you know this, but.... >=20 > At the Little Red Schoolhouse (Yamaha=E2=80=99s technician seminar in=20 > California), LaRoy Edwards likened the keyframe to a bridge: with the key= s (the load)=20 > out but the stack screwed on, the front rail and back rail are bedded firs= t=20 > (the two abutments at either end of the bridge), then the balance rail stu= ds=20 > are turned down to just contact the keybed (strip of newspaper pulled bet= ween=20 > stud and keybed has just a slight drag), then the keys are put back in. T= here > =E2=80=99s no spec. for =E2=80=9Cheight of balance rail=E2=80=9D, just for= key height, which is=20 > determined more by the keyslip and the fallboard. >=20 > The height of the balance rail is determined by bedding the=20 > keyframe and it ends up where it ends up.=20 >=20 > --David Nereson, RPT =20 >=20 >=20 As I understand it, LaRoy's reasoning for bedding the frame without the keys= =20 is that when there is no load (key weight) on the balance rail it will find=20 it's own "proper height" and then serve as an ideal and solid "foundation" f= or=20 key height/level. will ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/b2/36/c9/17/attachment.htm ---------------------- multipart/alternative attachment--
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