[CAUT] Sperrhake Harpsichord wire

Ron Nossaman rnossaman at cox.net
Sun Dec 6 14:53:10 MST 2009


Fred Sturm wrote:

>     So you are saying you ran those same notes and lengths and diameters 
> with Sanderson and Hays? And found no change in break%? If that is the 
> case, I guess I am willing to concede it isn't clear cut. 

It doesn't matter what numbers you run. With these formulas, 
the break% doesn't change. Is this starting to sound familiar?


>But I'd like 
> to see your figures just for the record, parallel to what I provided 
> (note, length, diameter, tension, break%). Doesn't take that long to do, 
> and, hey, if you convince me I'll shut up <G>.

There's no possible way I'll convince you of anything - ever.

Using your figures, C-4 goes 83lb, 94lb, 118lb, 145lb, and the 
break% remains 34% for both the Sanderson and Hays formulas.

For the C-7, it goes 147lb, 167lb, 210lb, 258lb, and the 
break% remains 61% for Sanderson, and 60% for Hays.

My numbers correspond to yours for the Rhodes formula. The 
other one isn't a formula at all, but a lookup table.


> But my mind is always open to the thought I could be wrong.

I've been noticing that.

Now, I'd like to state once more that none of the formulas 
anyone has are absolute gospel. None of them. The closest 
thing I have to truth here is from reports I've read through 
the years from facilities having done empirical testing on 
wire stating that break% doesn't change with wire size, if you 
average in enough batch testing. Zero change falls in the 
middle of the bell curve. Once again, the formulas that we use 
to calculate tension, inharmonicity, impedance, and break% 
aren't, and can't be, absolutely accurate. This doesn't render 
them less useful for their purpose, but picking two at random 
(which themselves don't nearly agree) isn't a useful indicator 
of an absolute premise.
Ron N


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