The
theory behind
the Stevens
winder is very
simple.
This
is a drawing
I
colorized
showing the
missing parts
of my winder
and how it
all works.
My
winder
was originally
only supplied
with the
'upper'
colorized
drive parts,
so I will use
that to
show how
my
winder is
supposed to
work.
The
main
drive
pulley is at
the far left.
This is driven
by a motor
and power
supply (not
shown)
to
control how
fast or slow
the winder
runs. This also
controls the
'clock'
turn counter
at
the top of the
winder and
also the blue
gear shown
inside the
gearbox.
If the main
drive pulley
rotates
once, the blue
gear inside
the gearbox rotates
once and the
'clock' also
goes to its
next 'tick'
position.
The
blue gear
rotates the green
gear and the
yellow gear
(behind
the
red heart
shaped cam)
to
set how fast the
red
cam rotates.
The red
cam is the
heart of the
winder... for
real. The
traverse rod
assembly
(the orange
rod) rides on
the red cam,
and the cam
makes the
traverse rod
move
to the left or
right to
feed the wire
evenly onto
the coil. The
gears inside
the gearbox
are chosen
to make the traverse assembly
move only
a very small
amount per
each
revolution of
the main
drive.
The
traverse
assembly guides
the coil wire
onto the
pickup bobbin
depending on
which gears
and cams
are
in the gearbox
when
it's being
used.
The
lower
colorized
parts are only
used on later
winders but I
include them
here
to demonstrate
how
cams work.
The
orange
traverse rod
rides on the
red cam. The
zigzag drawing
between
the part
mounted
to the
traverse rod
and the main
gearbox's side
is in real
life a
long coil
spring
like
the one you
would
find on an
'old school' house
screen
door. If you
turned the
crank
on
the cam
counterclockwise,
the traverse
rod would move
to the right.
If you turned
the crank
far
enough, the
flat area on
the cam would
make the
traverse
rod move very
quickly
back
to the left.
Basically, a
coil wound
with this cam
assembly would
have only
one
even
winding from
the left
side of
the
coil to the
right,
and a quick
movement back
to the
left
side
when the
winding was done.
Here
are some more
photos
demonstrating
how a cam
works.
This
is a bobbin
winder from a
very old
treadle sewing
machine with a
heart
shaped
cam mounted on
it.
The
pulley at the
far right
hooks onto the
sewing machine's
belt drive
to power this
winder.
The
screw
thread at the
top of the
winder is
really a worm
gear driving
the large main
gear.
The
cam is bolted
to the
main gear so
when the main
gear rotates,
the cam does
too.
The
worm gear is much
smaller than
the main gear,
so one
full rotation
of the top
worm
gear
would only
move the main
gear a very
small amount.
The
traverse
lever is the
lever riding
on the cam,
and it's resting
on the tip of
the cam so
it's
at
the farthest
lefthand point
of its
movement.
The
drive pulley
has rotated
about 50
turns, and the
main gear has
rotated about
90
degrees.
The traverse
rod has moved
about halfway
across
its
movement.
The
drive pulley has
rotated
another 50
turns or so,
and the main
gear has
rotated
180
degrees around
so the
traverse rod
has moved to
the farthest
right point
of
its movement. The
drive pulley
will rotate
about 100
times for
every half a
turn
of
main gear and
cam movement,
so each
single
complete
rotation of
the main gear
equals
two
complete
layers of
windings of
about 100
turns each.
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