Bass string making

[Delacour Pianos]

At 07:08 24/05/02 -0600, pianotech-digest wrote:
Date: Fri, 24 May 2002 00:56:47 -0500
From: "Richard Moody" <remoody@midstatesd.net>

>Having never seen a bass string being made I have a couple
>of questions.   Is the "eye" or hitch pin loop formed first
>and then chucked?

Yes.

>How tight is the string (core) when it is being wound?

That depends on the maker.  I was bartering tricks with a German
string-maker (Heller) at Frankfurt not long ago and he was insisting on the
importance of stretching the core to a tension similar to that it will
experience on the piano.  I think this practice is pointless and probably
harmful.  I have made every string for 15 years or at the same machine
tension (about 80 lbf) and have never produced a buzzing string as a result;
so take your pick.


>When winding I have heard much (esp overall
>diameter) depends on the tension the maker puts on winding.

That is true.  The effective diameter of the cover will be reduced by about
8-10% owing to the stretching and ovalization that occurs as the copper is
tightly wound on the core.

>Does this cause the string to "lag" which would be a kind of
>twisting?

Yes.  When the finished string is removed from the machine, the residual
tension in the copper winding causes the string to twist, but not enough
(provided the applied tension was sufficient) to cause buzzing.
Nevertheless, as I have written before, it is necessary for the stringer to
restore the tension thus lost by twisting the string on installation, and a
bit more into the bargain is all to the good.

>How fast does the core string turn?

I run the machines at top speed, which can be a bit frightening for a
beginner when you get to the 2.1 mm. copper!  I must admit I usually chicken
out at 1.85 mm. and slow the machine down.  My fastest machine runs at 6500
rpm and the older one at 5000 +.

>Does the machine give you a choice of winding both clock wise and counter
>clockwise?

Yes, but most of the work is done in one direction with under-cover fed from
left to right and top cover from right to left (or by some vice versa), so
that the wire goes over the top.  The reverse is necessary for swaging the
copper ends and other operations.

>Are there tests you can give it to see if it has any buzzes?
>   ---ricurious

A buzz will usually be audible when you break off the copper or flick the
string on the machine, but an experienced string-maker does not need to test
for buzzes, because if something goes wrong while the cover is going on, he
knows about it and starts again.  It's not worth taking risks.  Once a
string-maker has learned to apply the proper tension to the copper, it
becomes second nature to do it right.

JD