dented piano wireOFF LIST

[Ron Nossaman]

>It is similar to a shaper cutter.  Three wings, carbide tipped, 90 mm in
>diameter and set to cut approximately 6 to 7 mm deep.  (That last is from
>memory.  I'd have to go check to be sure.)
>
>Del
>


Now that's interesting, I was expecting something more like 40-50mm, or just
big enough to clear the pillow blocks holding the arbor. Out of curiosity, I
did some playing around, and found that 90mm, @6.5mm (split the difference),
puts the tangent at the notch edge at about 30 degrees from the bridge top.
40-50mm would leave, roughly, a 45 degree angle (+ -). The bridges I find
with a quarter sized (roughly 25mm) cut leave an angle of about 60 degrees.
You apparently feel that mass and stiffness is more important at the notch
edge than the termination point creeping forward as the bridge surface
crushes under the string. As in, why waste the string energy in a damping
notch, when it could be going to the soundboard? Would that be a safe bet?
Did you ever have string wrap clearance problems in the low bass when the
string winder centered the wrap a little too far toward the bridge? I have,
with hand notching in the 40-45 degree range at the edge. Or do you call the
string winder back and make one of those gentle suggestions? 

Ever since I saw a bridge notcher in use in a factory tour video some time
ago, I have wanted one. Oh yea, that's it, oh boy! With unusual optimism, I
figured about forteen bridges worth of time to build a dumbed down version,
if I didn't screw it up and have to start over too many times, with time
break even at about a thirty bridges. I don't have the volume demands to
justify it yet (maybe, maybe), but it doesn't hurt to accumulate any
information available in the interim. One never knows. 

That ought to be enough prattling for one post, so I'll stop before I'm
overcome by power tool lust and rush out into the shop to start building one
in spite of it all. <G>

 Ron N