> Well, fair enough, I certainly concur that bridge pins touching or > nearly touching struts are not an absolute indicator of something wrong. > Particularly if using vertical hitches, as that makes the string tension > plane adjustable: it could well be adjusted closer to the struts without > any harm at all. In the case of a standard setup, though, with bent > hitches and original string rests (duplexes or whatever), it wouldn't be > a "firm" indicator, but would, to my way of thinking, be a good reason > to take a second look before proceeding with installing strings. You > might well be putting an excess load on your board because you made a > mistake in your setup procedure. Fred, it's not an indication of anything at all useful, and using it as an indicator of where to set plate height will likely guarantee you'll screw it up. Vertical hitches, also, have not a thing to do with it. It's a simple matter of how much the board will deflect under load at the final bearing angle, vs how much initial unloaded crown. > It seems to me that the method of setting bearing you describe, > using wedges to emulate string load on the board, is another example > (along with not paying adequate - IMO - attention to EMC) of a weakness > in the process of "executing the plan." Some people do it that way, > others just add an initial amount of excess downbearing in hopes of > arriving at the target after the soundboard is under load of the > strings. Either way seems pretty haphazard to me, especially if coupled > with failure to control EMC at that moment. How do you make sure that > the wedges are exerting the right amount of downward pressure? Has > anyone measured to be sure? The wedge thing only works in a largely compression supported board, which is the vast majority of both existing and new boards being strung. It works with these boards because the wedge is driven in until the board pretty much stops deflecting when the panel reaches it's compression limit. When it's loaded with string bearing, it goes back to very near that same position. Low compression rib crowned and supported boards, which you're highly unlikely to have in the shop for stringing unless you built it, won't respond the same way. > It would not be that hard to do a pretty precise emulation. You have the information. Chasing the molecules to infinite precision without considering that information is your problem. I don't really care to play as an armchair quarterback. Good luck, and please let us know when you have a real world perfectly working setup. This has all been discussed, incidentally, many times over from every conceivable direction in considerable detail on the pianotech list through the years. If the archives are back up, it's all still in there. Ron N
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