groovey capo

[Overs Pianos]

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
_______________________

Web http://overspianos.com.au
mailto:info@overspianos.com.au
_______________________