Instability puzzler

[Farrell]

"With vertically laminated bridges, where it may be impractical to bend 
sharply enough to achieve this, the dogleg can be smoothed out a little..."

And there are methods of building bridges where one can make as an extreme a 
dogleg as scaling demands with no compromise to bridge pin position to the 
edge of the bridge. You don't need to "smooth out" anything!

Terry Farrell

----- Original Message ----- 

> ---- Jon Page <jonpage at comcast.net> wrote:
>> Back when I was tuning full time, I found that Yamahas in particular
>> were a problem
>> at the area. On a thread regrading that many years ago, I think it
>> was Ron O who suggested it was probably due to the difference of %
>> breaking strain across the strut.
>> A scaling problem basically.
>
> This is a common enough scaling problem, but one that can be overcome. 
> With a sufficient dogleg in the bridge, the speaking lengths can be 
> maintained at an ideal incremental value as between notes not divided by a 
> plate strut.  With vertically laminated bridges, where it may be 
> impractical to bend sharply enough to achieve this, the dogleg can be 
> smoothed out a little, and the back bridge pins moved forward on one side 
> of the break and back on the other, maintaining the same angle for side 
> bearing, leaving the bridge pins comfortably positioned on a bridge that 
> does not quite follow the shape implied by the bridge pin pattern.  I 
> never change wire gauges at the break, which would compound the 
> differences in beak %, tension, etc., at this critical point.  In some 
> designs where the note on the bass side of the strut is allowed to be 
> longer than ideal, the increment of wire gage is reversed, using a smaller 
> gauge rather than what one would otherwise expect, an ever increasing !
> wire gauge as you go further into the bass.   Most of the above is only 
> useful in designing or rescaling, but I have used a smaller wire gage 
> across the break in instances where I was not doing major bridge work on a 
> rebuild.
>
> Frank Emerson
>