[CAUT] Hardness of termination vs string breakage (was Re: restrung D)

[Jim Busby]

Ric,

I couldn't conjure up anything from the archives on the Spurlock tool,
but then I'm fairly inept at computer things...

I think Fred addressed capo dressing a few years back in his very
thorough manner. As I remember here is the gist of it; the v bar can't
be too sharp because it will wear/fracture too fast and soon be rounded
anyway, but now with string grooves. He also referred to a .5mm contact
point and that stuck with me. However, Ted hit the nail on the head by
using the word "curvature". Now if there is curvature there must be a
radius, arc, diameter, etc. or at least someway to quantify the curve.
Ted's method of referring to a drill bit size/radius works for me.
Maybe your V looks sharp but is actually the same as I see as a radius
at the very point. (Maybe all roads lead to Rome.) Or, maybe if you see
my redressed capo you'd say it's a V. It looks like a V, but it actually
isn't sharp. In fact, just the rounding of my flesh as I sand it rounds
it over to a small radius. The fret file just seems to make everything
more uniform and is very fast.

Regards,

Jim Busby

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
RicB
Sent: Tuesday, April 24, 2007 3:29 AM
To: caut at ptg.org
Subject: [CAUT] Hardness of termination vs string breakage (was Re:
restrung D)

Hi Jim

Please do see if you can spor it up.  It wouldnt be the first time 
different ways of describing something seem in dissagreement more then 
they end up being :)

But to try and specify better the profile I've always used.  It is  a 
definite V form, not an U.  Flat contact area to the string with the 
edges of the profile cutting away from this surface area as opposed to 
rounded of.

Ted said something about the  rounded profile compensating for the 
string length change in the initial phase of the strings vibration...  
the quote was

    "A vibrating string is quite evidently being stretched at 
    amplitude . and the consequent lengthening is offset by the
alternating 
    termination point caused by the deflection of the wire around the
radius of the bar"

      

This is simply false, no disrespect intended.  If a rounded termination 
could effect any change in speaking length it would do so only in 
vibrational directions close to vertical, and this would result in 
differences between those directions in other directions... and this is 
the whole single string beat thing again.

There IS a difference in resultant inharmonicity caused by the two 
different profiles. The sharp/thin profile allows the string to flex 
more around the termination, and the round/wide causes more of a bend.  
In the former inharmonicity is lowered slightly.  Whether that is or 
isnt a desirable is another matter entirely.

Again.. read McMorrows stuff on this, and there is a lot of discussion 
surrounding this in the archives.

I'm off and running !

Cheers
RicB

      

    Hi Ric,

    I'll check. Maybe we're talking different things here. I think 2.5mm
is
    the radius. Your .5mm profile might mean the same thing.(?) .5
radius
    would mean 1mm diameter. Am I thinking correctly?

    Have fun!

    Jim