This is a multi-part message in MIME format. ---------------------- multipart/mixed attachment OK. Here's a good illustration. You are, of course, correct. KR1 shows the KR taken at the capstan key contact. The KR measures .51. KR2 shows the KR taken at the top of an angled "capstan". The KR measures .59. KR3 shows the KR taken at a point directly below KR2. The KR measures .59. That was pretty simple. I'm convinced. I guess it's three to one now. David Love davidlovepianos@comcast.net If I understand Phil's explanation (and my small experiment), the KR > is a function of the combination of the contact point with the key and > contact point of the top of the capstan with the wippen heal. On a > straight up capstan there is not difference. If the capstan is angled > back at a 45o angle, the KR as measured from the very top of the > capstan will not be equal to the KR as measured from a point on the > key directly below the point of contact with the wippen heal. It will > be something between the contact point with the key and the point > directly below the contact point with the wippen heal. Therefore, > angling the capstan does lower the ratio (assuming the the same > contact point on the wippen), you just don't get the full benefit of > the new position vis a vis the contact point with the key. But maybe someone can provide the math. > > David Love There is no math. The moment arm is the straight line between the fulcrum and the contact point, regardless of whether the beam support between the two meanders through Sandusky, Minot, or Will-e-findit. The point at which the capstan enters the key is of no importance whatsoever, other than the angle it imposes on the capstan, and the angle at which the capstan contacts the wippen. The difference between the distance from the fulcrum and the point at which the capstan enters the key, and the distance between the fulcrum and the contact point between the capstan and wippen is utterly unimportant. The fulcrum to contact point is the measurement you need. If the angle between the capstan and wippen pad is such that the moment arm changes length through the key stroke, then the action ratio will change through the keystroke. That's it. It's really simple. Ron N _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives ---------------------- multipart/mixed attachment A non-text attachment was scrubbed... Name: KR1.JPG Type: image/jpeg Size: 42784 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/5a/48/79/74/KR1.JPG ---------------------- multipart/mixed attachment A non-text attachment was scrubbed... Name: KR2.JPG Type: image/jpeg Size: 44604 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/86/93/9c/6b/KR2.JPG ---------------------- multipart/mixed attachment A non-text attachment was scrubbed... Name: KR3.JPG Type: image/jpeg Size: 44567 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/22/75/8a/19/KR3.JPG ---------------------- multipart/mixed attachment--
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