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The
trick to drawing wire by hand is to grasp the tapered end that sticks
out the front of the drawplate with the pliers in such a way that there
are some 5 mm of play; of movement back and forth to the drawplate. Push
the draw tongs up to the plate so that when you start to draw there is
a little movement before the wire begins to go through the plate. If it
starts drawing with a jerk the inertia carries the wire on and as long
as you keep on moving it will not break easily. If you don't start by
using this jerk (usually obtained by bending the elbows and throwing your
body back until it's weight going backwards starts the wire moving) it
can be hard to start it. To find the correct hole to put the wire in next
take the back end of the wire and test it in the front holes of the drawplate.
When you find the hole it will not fit into then the correct hole is the
next one down.
To make
the taper on the end of the wire one may file a tapered groove into a
flat slope on the bench pin, lay the end of the wire in it and rotate
it while one files the wooden slope. This automatically generates a smooth
and even taper and is how pinstems are tapered when one only has to do
one or two.
An easier
method of tapering which simultaneously hardens the point somewhat and
prevents its breaking off easily during drawing is to step roll the point
in the wire rolls of a hand rolling mill. Roll the end in slightly, back
it out and put it in again at 90o to the first direction, then go to the
next smallest hole and do the same thing only not as far in on the wire.
Continue in this way until you have a smooth tapered point. Tubing too
can be step rolled to get a taper on the end for drawing it. One can solder
the tapered end for more strength.
People
use either beeswax or oil as lubricants. I prefer oil.
If you
need only a few holes of an odd shaped drawplate one can be made from
an old file, annealed, drilled and burred and filed to shape. The holes
must taper to the back and be as polished as possible. A flex shaft is
useful for this work. One can however buy drawplates from companies such
as TSI (see list) for 10.00 and less which with a little work with a toothpick
in the flex shaft and some steel polishing compound can be made acceptable.
Eventually one is better off buying a well made one. For larger sizes
of tube a hard wood, nylon or Delrin® drawplate can be made for drawing
down just a few holes.
One
can obtain various shapes by using a square and round drawplate. The wires
start out as either round or square and are drawn together with frequent
annealings until the proper shapes are achieved. For example a square
or round wire is flattened, folded over, soldered to close the 'loop'
and drawn through a square hole in the drawplate to produce two triangular
wires. One has to work with care to make this technique work well. One
can make half round wire by rolling a round wire into a thick sheet of
copper on the mill, the round wire then becomes a half round wire albeit
with a slight texture to the surface.
The
back of a drawplate also serves as a tool for shaping tubing to tapers,
both square and round if one makes an appropriate mandrel for the hole.
Note that the tool is not hammered in but pushed. Your drawplate is worth
more than a bezel forming tool so don't hammer into it. One can also "step
draw" both wire and tubing by drawing to a certain point, pulling it back
out the way it came in from and then going to the next smallest hole and
repeating the process. Richard Mawdsley uses this technique to very good
effect in producing stepped tubing for his complex constructed pieces.
A simple
wooden device may be constructed for holding draw-plates on the end of
a workbench or it can be as simple as two steel rods inserted in the bench
to pull against. This frees the vise for other uses.
In many
cultures one sits on the ground, draws the knees up, places the drawplate
against your feet and then straightens ones legs to draw the wire. Leg
muscles are much stronger than arm muscles and it is quite effective.
A draw
bench is extremely useful and one may be constructed from wood and canvas
or with a boat winch and board. If using steel cable instead of canvas
or leather belting steps should be taken to secure the end of the cable
from flying up loose and injuring someone if it is accidentally released.
An Asian Indian version uses leverage and a ratcheting motion to draw
wire on a carved plank on the ground.
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