Counterbearing angle

[Richard Brekne]

Delwin D Fandrich wrote



> I have designed these into several new pianos, though I don't know of any that
> are still using them -- the manufacturers seem to prefer struggling
> with improperly shaped and placed (but traditional) V-bars cast with the
> plate. Or, more frequently, they seem to prefer simply ignoring the myriad
> problems associated with improperly shaped and placed cast-in V-bars. >

Grin.... Del you wouldn't want to go on record stating your position on what the
"proper shape" for the capo bar is now would you. ??

> >What are the downsides to building up the counterbearing, if any?
> >
> > Time to do the job. Greater risk of string fatigue and breakage.
>
> Yes, and it's that second one that bothers me about the practice of
> hardening things around string deflection points. Especially at the V-bar.
> Every company I'm aware of that has produced pianos with hardened V-bars has
> come to regret the practice, though not all have admitted so. The warranty
> costs of replacing all those broken strings can be considerable.

Course now this leads back into another area we have er..... discussed before. I
gotta admit its not good for a poor corn farmer from Nebraska to make up his
mind..... some seem to like the bar hard and wide, others hard and thin, soft
and wide, still others soft and thin. Best arguments I have seen so far make me
lean towards medium soft, sharp and very thin. Tho Ron Overs made a good point
about pianos that are tuned very very often presenting a special case situation
in some correspondence we've had. But I will let him speak for himself about his
views relating to this otherwise.

> We harden string termination points in practice (either the V-bar or the
> counterbearing bar), though I've done a reasonable amount of experimental
> work with it. I've just not found it to be either essential or advantageous
> if the string deflection angles are in the ball park and the duplex length
> is properly short enough.
>

Neither have I. My own experience tells me that short, detuned front duplexes,
combined with a less then knall hard sharp and thin capo (0,5mm flat topped)
works best both as a precise termination, and for clear sound with minimal
leakage through the termination. I notice no string buzz after many years use
when this has been done carefully, and I have measured lower inharmonicity (if
this is desirable for some reason)  for this termination vs fat and round. Seems
to work best on low tension scales but I have nothing to support that with.

>
> Del

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:Richard.Brekne@grieg.uib.no