On Dec 2, 2010, at 3:03 PM, David Stanwood wrote: > I've been alluding to the possibility that a rep lever with very low > friction > can be regulated just fine IF the hammer weight and the spring > dimension > is well matched. I think you are probably right, at least with butterfly springs. There is probably a minimum friction level for them, but it seems to be pretty low, at least based on my experience with Steinway permafree. Other springs, though, behave differently, and I'm not sure what to think about them. In particular, Baldwin style (attached and screw- adjusted to the rep, a coil in mid air, then in a jack slot) and Schwander. I don't work with them much, but the last occasions I had to do thorough regulation, I found that in tripping the jacks lightly (to fine adjust rep lever height), the lever didn't want to support the hammer on most of them. I experimented with increasing tension to the max and re-pinning both centers pretty heavy, and the symptom persisted: better, but the jack still wouldn't go back under the knuckle when I tripped it lightly with a finger. In real life, they seem to function just fine, and I don't experience misfires, but it does worry me. Makes me glad most grands these days are butterfly. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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