I have no argument with this, or the reasons for it given by any of the posters so far. Fred writes: "Although what I have been writing in this thread has been aimed at a specific and fairly rare problem, I agree with David that minimizing space between cushion and shank will improve repetition in general (though maybe not terribly noticeably)." I just cant see CAF (as defined by Fred a couple posts back) getting into the picture. Try as I might with my action model... I could not find a way of causing this lock up in any way at all given reasonable action regulation, and good friction levels for centers and key bushings, even with the rest cushion totally removed. Nor have I ever experienced being forced to deal with the rest cushion distance to fix any king of jack missing problem at all in real piano situations. On the side... I did run into a D locally a few years back where a tech had experienced rep problems and tried to resolve them by putting in very loose jack centers and regulating the hammer blow way up... (I measured 38-39 mm blow distance). I have no idea what the reasoning for the latter was.... goes counter to just about everything. But the former I can at least see the rational for.... tho I disagreed with it. If the jack shows no apparent sluggishness in a manual test unrestricted by lifting the knuckle away from the rep lever... then it isnt jack speed thats the problem. Thats not to say there may be other reasons to address the jack center (as mentioned in some of the other posts).... but if the thing moves quickly... well then it moves quickly if you get my meaning. Cheers RicB
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