> This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ---------------------- multipart/alternative attachment Hi David, Good suggestion. Here they are. Alan =20 ORIGINAL NUMBERS =20 NOTE A1 A#2 F9 F#10 C16 C#17 C28 C#29 C40 C#41 C52 C#53 C64 C#65 C76 C#77 B87 C88 AVG D 69 67 65 70 69 69 64 68 65 63 57 60 58 57 71 79 63 67 65.6 U 40 37 34 36 38 41 43 38 41 41 36 35 39 37 48 47 44 46 40.1 F 14.5 15.0 15.5 17.0 15.5 14.0 10.5 15.0 12.0 11.= 0 10.5 12.5 9.5 10.0 11.5 16.0 9.5 10.5 12.8 BW 54.5 52.0 49.5 53.0 53.5 55.0 53.5 53.0 53.0 52.0 46.5 47.5 48.5 47.0 59.5 63.0 53.5 56.5 52.8 FW 41.0 41.6 40.7 37.4 37.0 37.2 25.6 30.5 25.0 26.9 24.2 24.2 15.6 18.1 1.9 1.5 -5.2 -8.6 SW 12.0 11.6 11.2 11.2 11.3 11.4 10.1 10.4 9.8 9.7 8.9 8.6 8.2 8.0 7.2 7.3 5.4 5.5 R 7.1 7.2 7.1 7.2 7.1 7.2 6.8 7.1 6.9 7.1 6.8 7.2 6.6 6.9 7.1 7.4 7.1 6.9 7.= 0 =20 NOTE KR WW WBW 16 0.56 18.1 10.14 17 0.56 18.0 10.08 40 0.57 18.2 10.37 41 0.56 18.2 10.19 64 0.56 18.5 10.36 65 0.56 17.7 9.91 AVERAGE WBW =3D 10.18 =20 KnuckleCore/CnterPin =3D 16.0 Capstan Convergence? No , Too low Bass Action Spread: 4.438=B2 Treble Action Spread: 4.438=B2 > From: "David C. Stanwood" <stanwood@tiac.net> > Reply-To: "College and University Technicians <caut@ptg.org>" <caut@ptg.o= rg> > Date: Tue, 26 Oct 2004 11:03:05 -0400 > To: <caut@ptg.org> > Subject: [CAUT] Re: Moving Capstans >=20 > Alan, >=20 > I can't access your .xls file either... > How about just giving us typed columns of numbers such as: >=20 > N U D FW SW KR WW >=20 > 16 25 50 28.0 10.4 0.52 18.5 > 17 25 50 28.0 10.4 0.52 18.5 > 40 25 50 28.0 10.4 0.52 18.5 > 41 25 50 28.0 10.4 0.52 18.5 > 64 25 50 28.0 10.4 0.52 18.5 > 65 25 50 28.0 10.4 0.52 18.5 >=20 > The above minimal sample notes give a good idea of what's going across th= e > keyboard. >=20 > To answer your question: You can tell how far to move a capstan by looki= ng > at the Balance Weight. As a rule of thumb, for every decrease in BW by > 1.0, the overall strike weight ratio will decrease by 0.1. If you have a > ratio which is 6.0 and you want to achieve a 5.5 just plug in the numbers > and solve the equation for BW: >=20 > BW=3D(SWxR+WWxKR)-FW >=20 > The result is your new target BW for making your desired strike weight ra= tio. >=20 > In the above samples the ratio calculates to 6.0 with a 44 BW. > To make a 5.5 ratio the target BW is 39. >=20 > When working with an existing heel cushion and a 90 degree capstan I do n= ot > recommend just moving the line but rather angling the capstan backwards a= nd > bringing the capstan line forward so that the capstan contact point on th= e > heel shifts forwards. For a small, medium, and large effect, try 4, 8, = or > 12 degrees. http://www.stanwoodpiano.com/CapRoll2.jpg >=20 > Isaac says we are in a geometrical world. It's not that simple. Yes we > have to pay attention to geometry but weight also has to be dealt > with. Both are important for the pianist. In regards to weight, my > formulas offer the clearest solutions. >=20 > As for Geometry... follow the rules and make sure you can regulate it. I= f > you are going for lower weight ratio (5.0 - 5.8) expect to use a minimal > blow distance of 44.5mm/1.75". If you move a capstan line, test the resu= lt > before committing to the new line. If the dip is too deep for a short bl= ow > distance then don't do it! >=20 > As a recent example: Last week Tim Coates, from Sioux Fall South Dakota, > was in my shop for PTD training and he brought a Steinway D action to wor= k > on. The strike weights were in the TopMedium range and he had tested the > tone by increasing strike weight with the addition of binder clips on the > shanks. Listening to the tone in the concert hall told him that 1/2 High > SW zone (a normal concert hammer weight) would give best results... >=20 > The average SW Ratio level was 5.8 and we wanted to go for a 5.3. We kno= w > from experience that a 5.3 ratio works well for the 1/2 SW level. We use= d > a capstan boat and found a position with an 8 degree angle that gave a 5.= 3 > ratio. We tested the dip with a 44.5mm/1.75" blow and it tested out at > 11.0mm/.433". This certainly would not do so we checked the > geometry. The capstans were set very deep in the key and the capstan/hee= l > contact point was way off the magic line. Everything else checked out > except the height of the wippen and and hammer center pins. Apparently > the action cleats were planed to thin in the Steinway factory. (Chris...= . > remember that Steinway D job we did were the tapered cleats had been put = on > backwards?) >=20 > Tim shimmed up the brackets. The front by 5.0mm/.20" and the back by > 8.0mm/.32", so that the center pin elevations matched the factory > spec. (Yes we checked for clearance under the pinblock.) Then we set the > capstan boat to make a 5.3 strike weight ratio and tested the dip with a > short blow. Now it tested out to 10.2mm/.400" and we noted that the > capstan/heel contact point came into acceptable alignment. Green Light! >=20 > I hope this helps. >=20 > David Stanwood >=20 >=20 > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/0e/06/6c/23/attachment.htm ---------------------- multipart/alternative attachment--
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