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Newsgroups: rec.crafts.metalworking
Subject: Re: Problem twisting 22g sq copper wire
Date: Tue, 02 Mar 1999 04:47:13 GMT

In article <7beuuu$5js$>, wrote:

> I want to twist 22g sq copper wire on my dremel to make wire bracelets.

One of the finer points of twisting wire (speaking as somebody who
does that one occasion for a living) is that just doubling the wire over,
and clamping it in a drill or dremel tool does not do a very good job.

The reason being that when wire is twisted like that, the individual
wires are being wrapped around each other, but they also want to
spin around their own axis.  Unless each wire is somehow free to
rotate around itself, they will build up considerable strain internally.

This shows up as the huge release of tension when you finally undo
the chuck at the end.  But the twists will not be tight and neat.

Big commercial outfits use a setup where the individual strands are fed
off of spools on a plate, and as the wire unspools the plate spins and
also each spool twists around itself.  But for small scale work you can
do two things:

One way is to tie a couple of small weights to the end of wires.  Then
set it up vertically so the twisting motor is at the top, and the wires
hang down.  Keep them separate with your hands - and when the motor
starts it will twist up, and each wire will be free to spin on its own.

The other way if you have a lot to do is to make up a couple of pin vises
with ball bearings on the ends.  One person holds the drill with the
wires chucked in it, and the other person holds the two pin vises a few
feet apart at the other end.  As the drill runs, the assistant brings the
two ends closer and closer.

We actually had about a mile of niobium wire twisted the *wrong* way
by a firm, and every 10 feet or so, the strain got to much, and one of
the conductors spun and fractured.  The entire lot was junk, and we
had to do it by hand.


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