Hi Vladan. I look forward to seeing this someday. I think the main point here is that its no good trying to look at just one aspect of this subject, throw a few of numbers together to form half baked models that dont take into consideration more then a small part of the total picture, and try and declare one <<knows>> whats is or what is not going on. I must again say I appreciate Phils cautious approach in this regard. Alan Bernard had it dead right the other day. No one really knows why strings can find themselves slightly away from the bridge. One can clearly identify some contributing factors but thats a long shot from declaring a full and final answer. To declare that string seating does no good at all is of course just plain wrong. To further declare that it is never more then a very temporary solution is also wrong, and given the argumentation used to justify that claim it is also a self contradiction. On the one hand it is stated that the clamp the bridge pins constitute is too strong to allow the string to migrate up the pins in any fashion and indeed the dynamics of the system in motion contribute to a re-enforcment of this clamping, whilst they on the other hand are not strong enough to ensure contact in the case of even very slight negative bearing at the front edge of the bridge. Then too.. the pins are able to, it is said, migrate up and down through the bridge pin hole, yet the same side bearing friction is again not enough to pull the string along with it. The effect of this side bearing friction appears and dissapears along the needs of the argumentation. Also... and this is the kicker... it is clearly demonstratable that strings have migrated some how or another up the pins and slightly away from the bridge cap in cases where there is positive bearing at the notch, (and plenty of it) and positive crown. Throw in what Dons film seems to depict by the descriptions so far, and all the other evidence around and I personally think its time folks stop trying to deny the reality of the fact and (assuming there is real interest in the matter) start trying to figure out why it happens. But thats just my take on the matter. Cheers RicB ========================= Hi Ric, Also, remember that the top of the bridge cap is not parallel to the soundboard surface. The edge facing the speaking length is higher than the edge facing the back scale. On Don's film, you can see the first pulse coming toward the bridge like a Tsunami. It yanks violently on the bridge pin and one wonders why the bridge pin doesn't get pulled out after you play a few loud notes. Vladan ============================ #3. The string under tension will not attempt to define a straight line across the top of the bridge. It will be forced in that direction by the bridge pins. The string under tension will attempt to define as exact a fulcrum as it can, and will start exerting pressure onto the edges of the bridge to do so as soon as tension is applied. The reverse of this condition is that the string being forced flat across the bridge by the pins will attempt to counter this and part of that countering is to exert an upward force on the string on the outside side of each pin. The edges of the bridge are essentially fulcrum points, and as with all levers... there is an equal and opposite leverage exerted on both sides of the fulcrum. Cheers RicB
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