> >>As a general rule it's safe to work the springs so that they just support > >>the weigh of the wippen. This would take about 9-11 grams off the touch > >>weight. 17 grams is generally considered the upper limit to working > >>springs without significant risk of comprimising normal feel. Some > >>pianists are more sensitive to the effect than others. > > > >Thanks. I was hoping for a number. So, that is 17 grams of spring assist > >at the capstan? > >No, that's at the front of the key. BTW when I refer to TouchWeight it >means Up/Down/Friction/Balance Weight. OK. > >On the particular action that I'm working on... > >I normally don't use assist springs. This is an old Hamburg Steinway O >action. > >It currently has assist springs which I am assuming are original. > >Also somewhat low key ratio. > >It's the overall ratio that you need to know... > > >Someone at some point set the springs very strong > >What's "very strong"? They are doing more than lifting themselves. > How many grams effect on U/D? 11 - 12 g. > Overlifting the wippen? Definitely. > >and took some of the weight out of the keys. I am planning to put on new >parts. > >My intention was to use 3/4 medium to top medium hammers. > >What's the average StrikeWt Ratio? An important question! 5.7 is good for >3/4Med SW, 5.5 for TopMed SW. 6 in the bass to a little over 6 in the treble. >6.0 won't do very well dynamically speaking unless the SW level is closer >to 1/2 med. > >The original set up was probably like a 6.0 ratio with 1/2Med SW. The current hammers as measured (with quite a bit of wear - and felt removed) are 3/4 Low. Maybe I need to think about making the new hammers a bit lighter then. >If you copy the old parts you'll probably get a ratio like 6.0. I was thinking of using a 17mm knuckle. So the SWR could drop a bit. >How far from the center pin to the center of the knuckle? > >David Stanwood I don't have the parts in front of me and I don't find it in my notes. I think 16.25 or 16.5. I'll have to check. Phil Ford
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