Mandocello nut
Hello,
I'm going to do a "reset up" and a K-5 style mandocello that made some years ago. I think that I want to move the four courses more to the center of the nut thus reducing the inter-string and inter-course distances. I think bar chords will be easier to make with that set up?
To that end I modified an Excel program for calculating nut configurations so that it would plot out how the nut would look if properly slotted. (the base program was originally written by Jerry Beyers a Cafe member). The top image shows the proposed new nut configuration the bottom image is the nut arrangement that I have now.
My concern is that I could end up with the C strings too close together? They could interfere with each other when vibrating?
Anyone know off hand a rule of thumb that relates string diameter (e.g., C string 074") to minimum inter-string distance in a course?
Here in the new set up I am proposing a distance of 0.23" (center C1 to center C2 string). This translates to a distance between the inner sides of the two C strings of 0.17". (that is 0.23" - 0.074")
Could there be a problem?
Open C on the mandocello is C2 fourth the wave frequency (f) is known to be 65.41 Hz. The length of its sound wave would be: λ = Vs/f (where Vs is the speed of sound and λ = wave length). Further we can get the amplitude (a) of the wave (trough to peak) by a = λ/f. So going through the numbers I get an amplitude of about 0.081" for the mandocello C-string. That seems reasonable to me?
So the two strings might have to be separated by 2X 0.081 = 0.162" to avoid touching
So maybe I'm on the edge of what might work with this set up? That a separation of 0.17"?
Or should I not equate amplitude of the sound wave with that actual movement of the string? I'm going to look into that but maybe someone else already has?
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
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