>/ As others have stated, one cannot disprove an event, that can be observed />/ and measured, by failure to explain why or how it occurs. All that is />/ proven is the limits of ones understanding of all of the forces at work. / This is in the end correct. But one has to be sure one has actually observed in an objective enough fashion.. The picture that was just posted : https://www.moypiano.com/ptg/pianotech.php/attachments/20060913/266e9f22/attachment.jpg is one I've seen before and was intriguing the first time I saw it. Upon trying this myself I found it was impossible to actually be sure of what angle the long center pin wire I used really had in the groove. So instead I checked by drawing a piece of 16 lb fishing line from the tuning pin under the capo (sometimes agraffe) and through the bridge pins instead of the string. A magnfying glass is all that is needed to see if there was any real gap. Fishing line being so flexible will mold itself readily around any curves and yet straighten out in a flash if there was nothing to curve around. I found that most of the angles I was running into on newer instruments showed no sign whatsover of a gap between the fishing line and the bridge at the pin. It just wasnt happening. I have indeed found pianos where this was the case. A very young Hamburg D tragically enough that had been subjected to some very aggressive string seating with a rounded off screwdriver by all accounts amoung those. That was when I started looking at the <<math>> from a little different angle. Now here, as far as I can understand is the deal. If you can find the highest point of the bridge surface (and that is easy enough to do) and establish the line from there down to the front termination for the string and find that at no point does any part of the bridge surface out to and including the pin and notch is below that line... then there is simply no way there is a real gap between the string and the bridge if the string is seated. If you can draw that same line and find the same result and find the string does have a gap when you put it on... its because its not seated. There is just no way around that simple truth I can see. All the denials that this is impossible are simply lost on me in anycase... because I actually have taken the postulate serious, put it to the test... and I find it in error. Sorry if thats inconvenient for anyone... but thats how it goes. The notch can indeed be behind the bridge without the groove necessarily causing a negative bearing situation. Simple trig and a few drawn triangles will show that to you in 5 minutes. Cheers RicB
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