You see the thing is, that either the ratio is the cause, or its not. Theres not really any inbetween here. Thats why its kind of important to confirm or deny whether a certain level of ratio neccessarilly results in inadequate jack clearance for given parameters. So if we take 10mm dip, 44.5 mm blow, 1.5 mm letoff as a standard, and say alllow for +/- 0.15 mm dip for wiggling room then it should be relatively easy to establish just what level of ratio (on the low end) actually does start causing problems. If you can regulate within these parameters at 5.0 as David Stanwood reports, well then you can. And if you run into a piano that has some difficulty at this low level then perhaps we should be looking at other action relationships to find the source of the problem, instead of just blaming it on the ratio itself. But to be sure... at some point the ratio will be low enough to make the action impossible to regulate for the standard parameters given above. And of course we will have the opposite situation at the other end of the action ratio spectrum. RicB David Love wrote: > Just to clarify my position on this a bit, I haven't yet encountered an > action where low ratios below 5.5 didn't create regulation compromises that > I found undesirable, and there it was pushing it. I hesitate to state a > general law because there may be other factors of which I am not aware. I > was surprised to hear David S. comment that he achieved 10 mm dip 44.5 blow > with an action that measured 5.0. That has given me some pause but doesn't > change my own experience. I have found it difficult to get a consistent > measurement depending on the method used and it is difficult to set up the > action with only a .01 margin of error, so I reserve judgment. For now, > however, I shoot for 5.75, if it drifts down a little bit in my setting the > cap line, for example, I don't lose any sleep over it. > > David Love > -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html
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