Bridge Root Spring-Forward

[Farrell]

"Again, I suspect this isn't unheard of, if not advertised, in manufacturing."

Oh gosh, where have I heard that very thing....... "Every one of our pianos is unique - every one of our pianos has its own personality"?

Hmmmmm, golly gee, where was it that I heard that.......

Could it be that the small shop is building pianos as good.....oh, err, I mean, almost as good as the NY manufacturer that need not be mentioned?

Oops. There I go again. Sorry 'bout that. I'll go crawl back into my little shop hole and behave myself.

Okay, back to the subject at hand. Ron, thanks for the reflection. That tells me that it is just something that happens. 

But now I'm curious: I can correct the small deviation in bridge shape with my pinky and just move the tenor tail over to where I want it and screw it to the soundboard - that way my design speaking lengths are maintained. From your description, it appears you are compromising your speaking lengths so that you don't have to induce a little bend in your bridge. I understand that your analysis of the string scale suggest that in the tenor section the small changes in speaking lengths are not critical - but why not just bend the bridge a bit and maintain the design speaking lengths?

Terry Farrell

----- Original Message -----  
> Yes, I'm using Titebond mostly so I can slop it all over me, 
> and likely will, without turning into Swamp Thing. I have to 
> leave it in the form for about three days though, to cure, 
> which wouldn't do in a manufacturing process. Out too soon, 
> they spring back a couple of millimeters. Left in for a week, 
> they sometimes curl in a bit. I have no idea why. 
> Occasionally, one exactly matches the form a couple of days 
> after I've taken it out and cleaned it up, but not often. 
> Planing them to height changes them some too. I suspect you'd 
> find the same thing in a high volume manufacturing situation. 
> I used to try to be very careful about maintaining my design 
> speaking lengths even when the unison footprint went 
> considerably off center on the bridge. Now, I've decided after 
> looking at the results on the scaling spreadsheet, that a 
> couple of millimeters length change either way in the lower 
> third of the tenor bridge is realistically undetectable. Now I 
> put the top two thirds of the scale on the bridge where I want 
> it, maintaining design lengths as closely as I can, and center 
> the unisons on the bottom third where they fall. Play it where 
> it lies. Again, I suspect this isn't unheard of, if not 
> advertised, in manufacturing. Horrors!
> 
> Ron N
>
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