Alan, I can't access your .xls file either... How about just giving us typed columns of numbers such as: N U D FW SW KR WW 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 The above minimal sample notes give a good idea of what's going across the keyboard. To answer your question: You can tell how far to move a capstan by looking 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: BW=(SWxR+WWxKR)-FW The result is your new target BW for making your desired strike weight ratio. 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. When working with an existing heel cushion and a 90 degree capstan I do not recommend just moving the line but rather angling the capstan backwards and bringing the capstan line forward so that the capstan contact point on the heel shifts forwards. For a small, medium, and large effect, try 4, 8, or 12 degrees. http://www.stanwoodpiano.com/CapRoll2.jpg 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. As for Geometry... follow the rules and make sure you can regulate it. If 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 result before committing to the new line. If the dip is too deep for a short blow distance then don't do it! 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 work 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... The average SW Ratio level was 5.8 and we wanted to go for a 5.3. We know from experience that a 5.3 ratio works well for the 1/2 SW level. We used 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/heel 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?) 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! I hope this helps. David Stanwood
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