String termination question

[Ron Nossaman]

> I don't think the primary purpose of a bridge pin is to prevent the 
> string from sliding around on top of the bridge. 

The pins serve two functions. They are the string termination, 
and they clamp the string to the bridge.


>Like a guitar or 
> other stringed instrument that possibility is minimal. 

Actually, it's pretty likely. I've run into a number of 
instances of mislocated bridge pins where the string made 
considerable noise on the bridge top.


> What I'm referring to is the need to make sure that the edge of 
> the notch on the bridge exactly matches the side of the bridge pin so 
> that the string termination at the bridge is the same in both the X and 
> Y axis. 

There is no such need. The notch edge needs to not be beyond 
the pin, as it'll make unwanted noise. It can be deeper, and 
behind the bridge, without penalty if the pin is solidly 
bedded at the top of the cap and not flagpoling.


>If it were not the same then the string is literally a different 
> length on one axis than it is in the other. Since a string moves in all 
> directions when vibrating, not just up and down, if that termination is 
> not exact then the partials created in one axis are different than in 
> the other, creating beats. 

It's not the vertical component of string excursion that's the 
problem, it's the horizontal. Strings don't typically slide up 
and down pins during play, but a pin that's loose at the top 
and flagpoling will cause the beat.

This isn't a factor at the capo, because the capo doesn't 
spring with vertical string excursion like the bridge pin does 
(if it's not tight) with the horizontal.

Again, this has all been described in vast detail for years in 
the archives.

Ron N