string termination

[Farrell]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
Comments interspersed below:=20

>> Carl Meyer wrote:
> Ron O replied:

>>A lot of things about string terminations have bugged me for some =
time.
>=20
> Me too. This is a topic which raises the level of pianotech list =
interest.
>=20
>>Ron Overs promotes hardening of the capo bar, yet the agraffe is a=20
>>relatively soft material (brass).  The difference is that the capo=20
>>is straight and the agraffe is round.  Wouldn't the agraffe last=20
>>longer if it were heavily plated with chrome, nickel or??
>=20
> It would last longer if it was plated with a hard or harden-able=20
> material. I think brass is a very poor material for string=20
> terminations. After re-profiling (both new and used agraffes) we have=20
> been plating them with Electroless Nickel for some years (since about=20
> 1996). This plating is harden-able, and it plates with a uniform=20
> thickness in the string holes. Normal electoplating won't result in a=20
> uniform build-up of plating in the holes, which is why Chrome isn't a=20
> viable alternative plating material. Electroless Nickel plating is a=20
> process which, once started, is a purely chemical plating process.=20
> This is why it results in a useful build of plating in the holes.
>=20
> For the most recently remanufactured piano we built, I decided to try=20
> just shaping the brass agraffe holes without plating and hardening.=20
> The results were very disappointing. The best results we have had to=20
> date are when the agraffes are Electonickel plated. We've been=20
> getting them plated with a thickness of 0.05 mm (2 thou). The next=20
> set we do will be plated with 0.75 mm to increase the strength of the=20
> plated surface. I have been suspicious that the plating is on=20
> occasion collapsing and flaking off, due to collapse of the soft=20
> brass substrate.

Ron - a typo? Do you mean the new plating thickness will be 0.075 mm (3 =
thou)?

Why then not make a agraffe out of steel or some other harder material? =
That may be difficult for the one-off small-shop piano builder, but if =
there were a demand to others..... Why would this be so difficult? Why =
would brass persist so long?

Why not use other termination types like a capo-type bar in all string =
sections like you see on cheap old American microgrands? What about =
something more like an upright pressure bar arrangement?
=20
SNIP
=20
>>Here's my question:  A vibrating string has two terminations.  It is=20
>>excited in the northern direction.  (Ignore the strike point)  What=20
>>effect on tone will be the termination of the two ends of the=20
>>string????? Both north, one north and the other south, east or=20
>>west????   Or no big difference??
>>
>>I have recently found plans on the net to build an led stroboscope.=20
>>I will build this and look at a string under vibration. I could=20
>>stretch a wire across my garage and look at it with different=20
>>terminations.
>>
>>If some of you deep thinkers have an answer to my question that=20
>>makes common sense, I won't have to do this.  Give me your feedback.
>=20
> It is a worthy field of investigation Carl. Conventional bridge pins=20
> suffer severe damage at the termination point. An intermediate=20
> solution would be hardened bridge pins, but it will be a costly=20
> exercise.

Hardened bridge pins would be costly? I can see such an argument from a =
Chinese manufacturer, but from a famous American or European =
manufacturer who "spares no expense to create an uncompromised =
instrument?" I realize that if a pin costs a nickel or dime rather than =
two cents, times 500 pins, that would increase the cost of building the =
piano by $15 - $40....... or am I missing something? Or are the =
upper-end larger, uncompromising, manufacturers really that cheap?

Terry Farrell
---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/34/3e/6a/d6/attachment.htm

---------------------- multipart/alternative attachment--