>I think I'm trying to say the same thing. If the bridge driller actually does >take into account the pin diameter, string diameter, and pin angle when >determining pin locations for the stagger angle then having a greater pin >angle doesn't need to result in greater pin load on the bridge. I was >assuming that most manufacturers followed the rule of having the hole >locations in a straight line between agraffe and hitch pin regardless of >other parameters. If so, then increasing the pin angle will result in more >pin load on the bridge, which would make cracking more likely, if this is >a primary cause of cracking, which I believe you're saying is not. Did I >do any better this time? > >Phil Hi Phil, You did fine the other times with the premise that the pins were positioned in a straight line... etc. I was just slow picking up on the premise. What can I say, it's a used brain. With the pins positioned on that line, consider this: #6 pin, #13 wire, 15.4mm spread between pin rows = 10° stagger. That same 10° stagger with the pins along that same line will result with #7 pins and #15 wire at 17.4mm - #8 pins and #17.5 wire at 19.6mm - #9 pins and #19 wire at 22mm - and #10 pins with #20.5 wire at 26mm. These figures are with vertical pins, so the row spacings would be somewhat wider if the insistence was that the pins remain on the line and still produce a 10° stagger angle. As you can see, we can either adjust the row spacing (if there's room on the bridge), or adjust the offset of the pins from that direct line, to accommodate the various pin and wire diameters, our choice of pin inclination angles, and the limitations of the bridge top surface we have to fit the whole mess onto. Limiting the choices to what we can get with the pins in that straight line between hitch and agraffe will mean deciding between pin angles and stagger angles as a priority somewhere in the scale. Both will likely be compromised at some point as a result, which isn't necessary if we're allowed to simply deviate from that straight line placement to make the other stuff fall where we want it. I think that straight line thing came about as a no fault, no argument, no thought, guaranteed way to get *some* side bearing on the pins of a replacement bridge or cap without having to figure out the math in the days before computers and spreadsheets. It works well enough if you don't insist on applying logic and standards requiring some sort of annoying uniformity of angles and such. Incidentally, the difference in stagger angle from 5° difference in pin angle isn't a lot with the pins in similarly located holes. Probably not even visible side by each. As for the load abuse on the cap from excessive pin angles, the more the angle, the greater the leverage on the surface of the cap, and the less the amount of wood on the side of the pin opposite the string pressure to back up and support the pin. It's got to be a factor in longevity, but I have absolutely no quantifying data. The theoretical idea is to find the balance between solid termination and bridge cap material abuse that provides the best balance between performance and longevity, subjective and actual. Stagger angle increases escalate material loads at a higher rate than pin angle increases, so I'd assign the first priority there, with the second priority being termination quality by pin angle. Until someone (might be you) comes up with a better bridge string termination system, we're stuck with trying to understand how the current one works and to try to make the best of what we have to work with. The hard part of that seems to be forgetting what we've been taught to assume about the silly thing, and assessing what we have to work with based on what we see rather than what we "know". Good evening. Ron N
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