Well, I wasn't interested in building an absolute theoretical piano model. I was just going to demonstrate as simply as possible the effects of the levers at work here. These are the figures from my own model and a guess of magnet weights. They'll suffice for the illustration. The first group defines leverage ratios and weights. center rail to magnet moment3 95 center rail to capstan moment2 120 keytop to center rail moment1 220 wip center to capstan moment4 63 wip center to magnet moment5 80 keytop to capstan lever1 0.55 keytop to magnet lever2 0.43 wip center to magnet lever3 1.27 magnet weight 0.8 wippen magnet assy weight 4.6 key magnet assy weight 1.6 no magnet - weight on capstan 92 DW= 50.18 This is what it takes in weight on the capstan to produce 50g DW. I don't care how it got there. add magnet weight to wippen 97.84 DW= 53.37 A 4.6g weight adds 5.84g at the capstan. This is a second class lever, where the effect of the force (weight) is amplified. add magnet weight to key 99.11 DW= 54.06 Add 1.6g inside capstan position, equivalent of +1.24g at capstan. First class lever, shorter moment arm, effective weight at capstan is less than that applied. define magnet lift 15 Arbitrary amount that made DW come out to about where it started - break even. add magnet lift to key 110.98 DW= 60.54 Magnet force pressing down on key. Effective force at capstan less than applied, just as with magnet weight. subtract magnet lift from key 91.95 DW= 50.15 Second class lever, effective weight reduction at capstan is more than that applied. -15g at magnet equivalent to -19.03g at capstan. The static weight of the magnets (6.2g) add 7.1g at the capstan. The magnetic repulsion adds another 11.87g, and lifts 19.03g. At 20g magnet lift, adjusting the gap smaller, roughly this would result. no magnet - weight on capstan 92 DW= 50.18 add magnet weight to wippen 97.84 DW= 53.37 add magnet weight to key 99.11 DW= 54.06 define magnet lift 20 add magnet lift to key 114.94 DW= 62.7 subtract magnet lift from key 89.54 DW= 48.84 Here, the static weight of the magnets (6.2g) add the same 7.1g at the capstan. The magnetic repulsion adds another 15.83g, and lifts 25.4g, reducing DW.
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