capo-hardening/string breakage

[Ron Overs]

Bob Hohf wrote:

>There's something about this capo string breakage that I haven't seen
>mentioned here yet. This isn't the one answer to every case, but I've seen
>this condition in two Ds that I've rebuilt. It's worth checking out
>especially when the replacement stings keep breaking, too.  The machined
>round surface on the bottom of the capo that provides the termination has an
>"edge" on both sides.  Sometimes the round surface doesn't extend far enough
>around the bottom of the capo, and the strings terminate on the edge rather
>than tangentially to the rounded surface.  Obviously, this situation will
>create a very abnormally high stress right at the edge that will resist
>string rendering and greatly accelerate the process that causes the strings
>to break.  With the strings out you can see exactly where the stings
>terminate by looking carefully at the grooves, with a magnifying glass if
>necessary.  The solution is to reshape the bar and remove the edge.

Well put Bob, the shape of the bar must be properly pro-filed, not 
just flat-filed as is often the case with Steinway capos. Multi 
faceted bars kill the tone as well as the wire. Another speciality of 
many manufacturers, is the way they get lazy when shaping the the 
capo radius as it approaches the plate strut. This is why there is 
often more string noise adjacent to the struts. A lack of 
thoroughness once again yields a lack of performance.

Nice to see you in print Bob, following our meeting at Reno.

Ron O.
-- 
Overs Pianos
Sydney Australia
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Web site: http://www.overspianos.com.au
Email:     mailto:ron@overspianos.com.au
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