John D, Del et al, >At 8:09 AM -0800 11/29/01, Delwin D Fandrich wrote: > >>Sigh! How things change with time. Or, perhaps I should say, how our >>perceptions change with time. >>When I started in this business a key travel of 9.5 mm (0.375") was >>considered the norm and Steinway's 10 mm (0.395") was, by many, considered >>some on the deep side. > >How old are we Del?? No older than me, for sure, and off hand I can >think of no grand piano since 1880 that will take a 9.5 mm touch >with a 48 mm blow and get a clean escapement. The only piano that >has such a shallow touch is the Blüthner, which has a patent action >and a recommended blow of 43 mm. > >So far as I know, action design and key ratios have not >significantly changed in the last 100 years and there are many 19th >century pianos, grand and upright, that require over 10 mm touch >depth. 3/8" has never been anything but a theoretical figure and >has never allowed for escapement. I can't say I agree with either of your above paragraphs. Have you kept records of the actions you have measured over the years JD? I'm surprised at your claims. During the early 1900s actions were set up typically with hammer/key ratios between 7 - 8:1. For example; Steinway 1906 model 0 183/217 x 95/67 x 138/20 = 8.25 Whereas in recent decades lower ratios have been used to cope with the heavier modern hammers. For example; Yamaha 1992 C7F 145/265 x 92.5/65 x 138/20.5 = 5.24 The earlier actions with a higher leverage ratio will work very well with under 10 mm dip, while the modern shorter ratio actions will fail to get sufficient jack clearance of the knuckle unless more dip is used. You mentioned yourself about the importance of jack/knuckle clearance in the after touch position. Both Hamburg Steinway D and Fazioli 278 have a ratio of nominally 5:1. These pianos most definitely will not function with a dip below 10 mm. I have found 10.25 to be a workable minimum in both cases. This change of the hammer/key ratio from higher formerly to the modern lower figure is precisely why you cannot fit a modern denser and heavier hammer set to an older piano with a higher ratio, ie. unless you are prepared to move the capstan position and the knuckle slot to revise the ratio back to what will be required for proper function. Ron O -- ______________________________ Website: http://www.overspianos.com.au Email: mailto:ron@overspianos.com.au ______________________________
This PTG archive page provided courtesy of Moy Piano Service, LLC