>With a dial or stick gage, > >your overall bearing will have to take into account the vertical offset > >across the bridge from front and back bearing (which you don't know), as > >well as deviation of the back scale from the plane of the speaking length > >where the gage is resting - all of which is dependent on the length of the > >gage and width of the pin row spacing. > >Which limits their utility in communicating information (it's hard to know >if everyone is on the same page, so to speak), which seems to be one of >David's concerns. And mine, which is why I've always advocated discussing bearing in degrees. >At some points on the bridge the feet of the gage have to be so close >together that whatever reading you take seems suspect. I think so. >I agree. Although, unless there is a severe mismatch between string angle >and bridge top angle, I even question whether there would be a termination >issue. For slight mismatches (even for some amount of negative bearing) I >think the bridge pins are going to work well enough to terminate the >speaking length. They do, which is why you can measure negative front bearing in a whole lot of pianos out there that aren't exhibiting any specific tonal problems undeniably due to negative front bearing. >I think these numbers could perhaps, at least on a new >board, be an indication of a potential bridge rolling problem. Not by themselves. A trip underneath with a string and flashlight to check crown in the area the suspect bearing readings came from would tell a much more complete story. > It seems to >me that if you choose the amount of bearing you want to put on your board, >then the ideal way to put it on would be with front scale and back scale >forming the same angle to the bridge, so that forces on the bridge at its >front face and back face are the same. If they are not the same, then it >seems there is the potential over time to roll the bridge. I don't think that typically has anything to do with bridge roll, which is essentially soundboard structural failure. >Explain to me the > >process of using the stick. > > > >Ron N > > >Well, first you walk softly ..... > >Phil Ford Speak softly, maybe? Ron N
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