larger bridge pins

[Ron Nossaman]

Isaac,
This came privately, but I'm sending it back on the list. I know you got a 
private response from me on the last one, but your response line had both 
you and pianotech listed, so it went to both. If your mail program has a 
"feature" that blocks one source if duplicate messages come to the server 
from two different sources, then you're only getting the reply from me, and 
not from pianotech. I think that's what's happening here.

>A rotary diamond grit, or a diamond stone for the chisels ? I have a
>grinding wheel, but not very strong stone, and a water stone (turning,
>a Tormek).
>May be with  little grit tools in a drill I an do that ?

Whatever works. I have a couple of flat diamond grit "stones" (steel) that 
I use on shop knives and chisels. A half dozen strokes on each edge is 
about all it takes. A flat stone would work as well. A grinding wheel, if 
you're hand is steady and your eye sharp should work too.


>Not sure I can make that one, I'll try tomorrow.
>
>If no may be if I try to have the begin of the bit smaller.

Then try it on scrap first.


>I wonder too if I gain something surfacing the top of the bridge, as I
>will not go below the strings grooves anyway, what advantage is there
>to do that ? (are the string grooves on the bridge really bad for the
>tone ?)

I'd flatten the bridge top to get the middle the same height as the bottom 
of the grooves at the edges. Those grooves represent crushed wood, and a 
string rest path rounded down at the edges. You'll get a better termination 
flattening the top.


>Admittedly I could shape the bridge to correct a (very little) rolling
>motion, but I am in trouble with the DB after that.

You have to decide that yourself. Is there enough crown in the board so you 
can position the plate height to get adequate bearing without pushing the 
board flat, or beyond?


>Do you believe that adding DB in the middle of the board stiffens the
>killer octave, or is the opposite a better way (less DB in the middle
>to expect a bit more life in the killer zone ) All that under less
>than good conditions unfortunately (very small curve)?

Maybe temporarily, but isn't a fix, and will shortly be a problem again if 
it's a problem now. None of the tricks you have heard about fixing killer 
octaves caused by a too low impedance board will work except replacing the 
soundboard.


>I believe that adding some back bearing (grinding the aliquots ) give
>some strength to the tone, but I feel the tone is really not as good
>then so is it an option, really ?. On an old piano I keep DB minimal,
>I've seen more than once the case where too much was too much, or the
>soundboard collapsed after a few years.

Bearing should be set with crown and the stiffness of the board in mind. If 
the board is dead, it's dead.


>I will have a soundboard press in January (with go bars) but have a
>too limited experience in wood working now, I may absolutely find
>someone to work with on these matters !
>
>Best Regards.
>
>Isaac

I recommend pneumatic. There have been a couple of list discussions of 
pneumatic press use recently. Check the archives first, before you start 
building.

Ron N