At 16:51 -0800 10/1/10, Jason Kanter wrote: >John, could you please add a definition of PROFILE? Jason, I though it was pretty clear from my definitions, which you quote in your message -- see the definition of KEY RISE, rendered bold below. "Contacting profiles" is a Pfeifferism that both I and Nick G. have used in this thread : At 13:11 -0700 12/1/10, Nick Gravagne wrote: >In brief, this conjugate relationship is intended to minimize >friction by creating a "rolling" rather than "sliding" friction at >half-stroke and thus "minimize the slide path" of the contacting >profiles (capstan, whip heel, etc.) Here are shown the arcs traversed by the capstan and the lever heel. Friction will increase as the arcs diverge. >[...] >On Sat, Jan 9, 2010 at 4:34 PM, John Delacour ><<mailto:JD at pianomaker.co.uk>JD at pianomaker.co.uk> wrote:<snip> > >>DEFINITIONS: >> >>The BASE LINE is a horizontal line parallel with the key drawn >>through the balance point of the key. >> >>KEY DIP: An arbitrary figure of 8mm is taken as the (perpendicular) >>downward travel of the front of the (natural) key. (8mm of arc >>would make a really tiny difference) >> >>KEY RISE is defined as the perpendicular distance moved by the >>contacting profiles (lever heel and capstan top). >> >>The KEY FRONT LENGTH is the distance along the base line between >>the balance point and a perpendicular drawn from the key front. >> >>The KEY BACK LENGTH is the distance along the base line from the >>balance to a perpendicular drawn from the midpoint of the profile >>(the top of the capstan). >> >>The PROFILE HEIGHT is the perpendicular distance from the mid-point >>of the profile to the base line. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100115/95956ab9/attachment-0001.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: Pasted Graphic.tiff Type: application/octet-stream Size: 272542 bytes Desc: not available URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100115/95956ab9/attachment-0001.obj>
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