groovey capo

[Sarah Fox]

Hi Ron et al,

I might just try this approach when I eventually take on the restringing
job.  Two questions, though:

(1) What dia of drill rod stock do you recommend?

(2)  Is there some gizmo (Dremmel?) that will grind the perfect recess into
the capo?

Thanks!

Peace,
Sarah


----- Original Message ----- 
From: "Overs Pianos" <sec@overspianos.com.au>
To: "Pianotech" <pianotech@ptg.org>
Sent: Wednesday, November 24, 2004 3:50 PM
Subject: RE: groovey capo


> Elwood, Don, Sarah and all,
>
> >At 9:23 AM -0600 24/11/04, Elwood Doss wrote:
> >
> >I'm assuming the capo d'astro rod can be replaced.  I've seen a few
> >older pianos with the rod configuration on the capo.
>
> Its an excellent idea, but the rod must be well
> seated all along the capo, or the tone with
> suffer where the bar is not firmly located. A
> former employee once re-fitted a bar carelessly,
> allowing the end of bar to ride slightly out of
> the groove. The tonal deterioration, right where
> the rod was riding the cast, was obvious. He had
> to loosen the string-section tension and tap the
> rod along to where it belonged and re-tension the
> section.
>
> Yamaha used a hardened bar in the first of their
> V process plates (around 1977). They were
> claiming a bar hardness of C60 on the Rockwell
> scale in their literature of the day (piano wire
> is around 45C). However, they were using quite
> conventional string approach angles and they ran
> into problems with string breakage quite quickly.
> I think the idea was excellent, and it worked
> very well for those instruments which were being
> maintained by techs who were careful not to move
> the strings too much when tuning. For those
> pianos which routinely were being reefed all over
> the shop, string breakage would set in real quick.
>
> >   It makes sense to
> >make it replaceable, rather than having to dress the v-bar when the
> >piano is restrung.
>
> If the rod or indeed just a plain capo is
> properly hardened it won't need reshaping again
> when the piano is re-strung.
>
>
> >From: Don [mailto:pianotuna@yahoo.com]
> >Sent: Tuesday, November 23, 2004 9:22 PM
> >To: PTG
> >Subject: groovey capo
> >
> >Hi Sarah,
> >
> >Young Chang (among others, I'm sure) has done a "rod"
> >It can work well if the "right* material is chosen.
> >Sometimes it is not field tested enough. There *can*
> >be too much friction for the strings to render.
>
> There can, but only if the bar isn't hard enough.
> A harder bar will have less friction because the
> strings will sit on the bar instead of digging a
> groove into it. However, if the string approach
> angle is too high, a hard bar will result in
> considerable string deformation. This can result
> in premature string breakage. The solution is to
> avoid too much string approach angle. I don't let
> it go over 15 degrees.
>
> >. . . On Bosendorfer pianos the capo can be removed. I
> >suppose that means it can be replaced.
>
> The Bösendorfer capo can be removed, reshaped
> then hardened separately, which is very
> convenient. We've done it several times.
> Bösendorfer haven't discovered the advantages of
> a properly shaped and hardened bar yet. I had an
> experience here a couple of years ago where a
> local tech, who is a known trouble maker, went
> running to Bösendorfer to tell tales about 'the
> nasty southern tech' who was hardening their
> original soft capos. Bösendorfer obliged by
> replying that they regarded such work as
> experimental. The local tech seemed to be fishing
> for an excuse to bring my work into question. It
> all worked out very nicely for him. His scare
> mongering encouraged the client not to pay for
> our work, and he now 'maintains' her piano - very
> cosy. I notice that the piano owner/musician has
> the particular Bös Imperial listed on her
> website's recording studio inventory. Strangely
> enough, there's no mention of the fact that she
> got the capo section repaired without actually
> paying for it.
>
> Ron O.
> -- 
> OVERS PIANOS - SYDNEY
>     Grand Piano Manufacturers
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