dented piano wireOFF LIST

[Delwin D Fandrich]

----- Original Message -----
From: Ron Nossaman <nossaman@SOUTHWIND.NET>
To: <pianotech@ptg.org>
Sent: Tuesday, August 10, 1999 4:35 PM
Subject: Re: dented piano wireOFF LIST


>
> >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.

That, and the hold-down plate.



> 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?

I'm not a betting person, but...



> 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?

No.  But, if we did the strings would go back.



> 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.

Well, it depends.  I was never very fast at bridge notching.  With this
thing it takes me about 45 minutes.

Del