Hi Terry, You've got the clue in your question: > the boring distance should be like on a grand - > just >> a hair longer than where the shank becomes parallel with the strings This is usually true of grand actions, but in verticals, the hammer contacts the string _before_ the shank becomes parallel to the string, therefore, in order to strike the string at a perpendicular, the hammer must be a little less than 90 degrees. Take a look at your vertical action model. Ed Sutton > - ----- Original Message ----- > From: Farrell <mfarrel2@tampabay.rr.com> > To: <pianotech@ptg.org> > Sent: Monday, August 27, 2001 6:47 AM > Subject: Hammer Boring Angle > > >> Is there ever any good reason to bore a hammer on an upright such that the >> long axis of the hammer & core and the shank form an angle less than 90 >> degrees? I'm putting new hammers and butts on an upright and don't want to >> repeat original mfg. errors. I should think the hammer/shank angle should > be >> exactly 90 degrees and, just >> to allow for a small amount of hammer wear. Original hammer core/shank > angle >> is about 88 degrees. >>
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