This is a multi-part message in MIME format. ---------------------- multipart/related attachment ------=_NextPart_001_0015_01C41E69.474107A0 MiniMens piano string simulator introduces the new "contact ratio" = parameter for analyzing the break in the scale from blank strings to = wrapped strings. On the lower strings, it is possible that the hammer has multiple = contacts with the string. (see contact force graph) contact force history for key F-21, string length 1475 mm (58 inch) = diameter Nr. 20 (Steinway model B) hammer speed 3 m/s. The single peak = at 11 ms indicates the recontact of the string with the hammer, when the = wave arrives the hammer after the bridge reflection. Contact ratio means contact time of all contacts of the hammer with the = string, divided by the time, the wave needs to run from the hammer to = the bridge and back to the hammer. If the time is equal, the ratio = becomes 1.0, what means that the hammer is in a synchronous movement = with the string. A lower contact ratio will produce a more partial = pronounced tone, whereas a higher contact ratio increases the losses of = the higher partials. It has been found, that on good instruments (like the Steinway Model B = or D) the wires are always choosen in that way that this contact ratio = has nearly the same value (but only true when considering all contacts). = Changing only 1 diameter of the copper wire more or less, will already = produce different contact ratios. Since it was not possible to do = dynamic simulations at the time when this scales where designed, one = must assume that the best fit was found by try. It is amazing to find = with dynamic simulation the proove that the scale designers had found = the best wire combination.=20 (first numeric field is contact time, second field ist wave time) =20 original contact ratio (0,64) for F21:=20 string length 1475 mm (58 inch) diameter 1,125 mm (0,0443 inch) original contact ratio (0,64) for E20: (contact times and wave times are = different) string length 1025 mm (40,35 inch) core wire 0,95mm (0,0374 inch) wound = wire 0,55 mm (0,0217 inch)=20 modified contact ratio for E-20 (red marker for E-20, blue marker for = F-21): string length 1025 mm (40,35 inch) core wire 0,95mm (0,0374 inch) wound = wire 0,6 mm (0,0236 inch)=20 modified contact ratio for E-20 (red marker for E-20, blue marker for = F-21): string length 1025 mm (40,35 inch) core wire 0,95mm (0,0374 inch) wound = wire 0,5 mm (0,0197 inch)=20 The contact ratio parameter together with inharmonicity are very = important paramters that will limit the number of wire combinations at = the scale break and helps greatly to reduce sound differences at this = most delicate part of the scale. Best regards Bernhard Stopper Klavierbaumeister Info about the MiniMens/Mensurix Software at: http://www.piano-stopper.de/html/homepe.htm ------=_NextPart_001_0015_01C41E69.474107A0 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/5e/db/60/32/attachment.htm ------=_NextPart_001_0015_01C41E69.474107A0-- ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 36575 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/f4/15/5b/9d/attachment.jpe ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 17220 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/8d/75/24/b8/attachment.jpe ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 15826 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/87/a4/34/c1/attachment.jpe ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 16012 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/ee/1a/bb/8a/attachment.jpe ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 16742 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/27/d9/a5/f6/attachment.jpe ---------------------- multipart/related attachment--
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