To the best of my knowledge, changing the bore distance changes the shank upper lever arm and thus the hammer shank ratio. This changes the movement at the knuckle, the lift at the capstan and the key leverage. Unfortunately and most unconveniently for the sake of simple trig, the shank angle at rest is only equivalent to the shank upper lever arm when the bore distance is equal to the blow distance. Humbly submitted, Jude Reveley, RPT Absolute Piano Restoration, LLC Lowell, Massachusetts (978) 323-4545 ----- Original Message ----- From: David Love To: pianotech at ptg.org Sent: Tuesday, March 24, 2009 2:24 PM Subject: Re: [pianotech] Increasing bridge height It does? How. If you raise the string plane and increase the bore distance accordingly so that the shank angle at rest is the same as it was before, how does the leverage change? David Love www.davidlovepianos.com Of course, changing the bore distance does affect the entire action leverage... Jude Reveley, RPT Absolute Piano Restoration, LLC Lowell, Massachusetts (978) 323-4545 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090324/4ca004a0/attachment.html>
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