pinning bridges

[Ron Nossaman]

Hi Del,

>> 1. Scaling: This involves foreshortening the speaking lengths of the >
--------

>Yamaha is not the only piano builder who has used -- still uses? -- this method
>of bridge drilling.  It may be the least noticeable, visually, but this is
>already an awkward portion of the scale.  Why make life more difficult than it
>already is?  There is really no need to use this 'solution.'

* I played around with this a little after I had posted the original
observations, to see what I could come up with. It got a little strange, so
I see what you mean. Still, out of curiosity, I think I'll get a few
measurements from a live one the next time I get the chance just to see what
they considered acceptable deviation. 




>> 3. Aiming the pins: When the builder feels the pin placement is where it 
---------------------
>This is easily done if the bridge is being hand drilled.  It is somewhat harder
>to do if the bridge is being drilled and pinned by automatic machinery.  It
>requires another level of sophistication in the machine doing the work.  Again,
>it is not usually necessary.

* When I first started noticing the scaling trick in the Yamahas, I wondered
if it was to accommodate, or simplify, an automated drilling system, since
every unison could be drilled the same. So it would seem.  




>> 4. Getting lucky: If the crossover point coincides with a plate strut,
-------------
>In my view, at least, this consideration would be well down on the list in
terms
>of locating plate struts.  

* Good, I just sort of threw that one in for aggravation anyway. 



>It is far easier to float the pin spread by varying
>the spacing between the front row and the back row of pins.  As long as
there is
>adequate compensation made for the string deflection angle by offsetting the
>back row of pins slightly, there is really no major drawback to this solution.
>It's clean and simple.
>
>Del

* The bridge on my S&S B seems to have some scale blending on either side of
the strut at this point. I (dumbly) didn't know exactly what I was going to
do with the piano when I tore it down, so I didn't measure the scale and
don't have the numbers to answer my own question. I'll be able to eventually
but the pieces back together and reconstruct the scale, but in the mean
time, was this done on this model, or is my eyeball out of calibration? BTW,
this isn't Steinway bashing, it's just what I happen to have around to look at.

 

Thanks,
 Ron