The added
parts are my
stepper motor
(under the big
black gear) in
the middle,
a matching
rack gear
mounted to the
traverse rod
for moving the
traverse drive
left and
right,
two submicro
sensor
switches set
up as a zero
set 'axis
home' stop (so
the computer
knows where
to stop the
traverse), a
blank PC
protoboard for
adding new
control
circuits,
and the Arduino's
infrared LED
rotation
timing sensor.
This sensor is
the heart of
the system...
its light
pulses tell
the Arduino
not only when
to tell the
stepper motor to
move the
traverse
to
properly wind
the coil wire,
but also
control the
main motor's
speed
and also
automatically
shut itself
off when the
pickup's coil
is full!
Want to learn
how?
Read on
This
photo shows
the rack and
pinion stepper
motor drive
that replaces
all of
the
missing cams
and gears. The
stepper motor
drive gets
timing pulses
from the
Arduino
computer that
tell it when
to turn on
(move) the
stepper motor,
which
direction
to move it in and
how far it
needs to go.
The rack gear
rides on the
stepper motor
gear
and is
attached to
the traverse
rod so
when
the stepper
motor turns
the traverse rod moves
back and forth and
the pickup's
coil wire is
wound neatly
onto the
pickup.
Where does the
Arduino get
its timing
pulses from?
The infrared
LED timing
sensor at
middle left.
This assembly
takes the
place of the
first timing
gear in the
original
drive.
Basically,
when this
winder was
new, every
time the main
drive shaft
rotated once,
one wind of
wire
was deposited on
the pickup
coil, the
clock counter
'ticked' once,
and the gear
originally
bolted
to the shaft
this assembly is
now mounted
onto also
turned once.
This gear
moved the
other
gears and
the cam also
in this
gearbox to
move the
traverse drive
rod at the top
of the photo.
Now, the very
small black
box is an LED
infrared light
emitter and
detector
setup,
sort of like
the one in
your TV's
remote control
or in a
computer
mouse. The
silver shape
is
a shutter that
blocks the
light from the
LED in the top
of the sensor
from shining
on the
detector
in the bottom
of the sensor
for half of
the
mainshaft's
rotation, and
lets the light
shine through
to the
detector for
the other half
of the
rotation.
These
alternating
light/dark
pulses
every time the
shutter
rotates over
the detector
makes a
regular
voltage pulse
that the
Arduino can
sense. These
pulses tell
the Arduino
that the
pickup is
rotating
and how fast
it's going,
and the
Arduino counts
these pulses
and uses this
information
to control the
rest of the
winder's
movements.
Neato.
The two
switches
pressing onto
the rack gear
at the upper
right will be
zero count
or "axis home"
switches for
the Arduino.
Since this
winder is
basically a
counting
machine,
closing these
switches will
tell the
Arduino that
this switch's
point is
'zero' and the
stepper motor
cannot move
any farther to
the left than
it already is.
This keeps the
machine from
crashing
(or damaging
itself by
going too far
to the left).
This shows the infrared LED shutter assembly at its
'closed' or
'off'
position.
When the
silver shutter
is in this
half of its
rotation, the
light shining
from the LED
in the top
of this sensor is
blocked from
the detector
in the bottom
of the sensor
so there is no
voltage
output from
the detector.
If
there is no
voltage output
from the
detector, the
Arduino
doesn't do
anything.
This photo shows
the 'open'
infrared light
sensor with
the light
shining from
the LED
on top of the
sensor to
the light
detector at
the bottom of
the
sensor. I
am using an
infrared LED
for my sensor so
its
light cannot
be seen by
humans.
When the
silver shutter
is in this
half of its
rotation, the
Arduino sees a
voltage at the
input pin
connected to
this sensor
and knows that
the main drive
has rotated
once - so it
adds one count
to the total
winds counter
and also tells
the
stepper motor
to move in the
correct
direction
a distance
equal to one
wire diameter.
For example...
if the counter
is originally
at count
number 100 and
the diameter of
the coil
wire you're
winding is
.005 inches
(five
onethousandths
of an inch),
the position
of the
traverse's
stepper motor is
"100 counts"
or .500 inches
from the
'zero'
starting point
(traverse
moving from
left to right as
you look at
the winder).
When this
shutter piece
rotates to
this position
the
infrared light shines
on the sensor,
which tells
the computer
to add one
count to the
total count
(from
100 to 101) and
the stepper
motor moves
right from
.500 inches
from left zero
point to
.505 inches. The
computer
continues
doing this
until it gets
to the point
corresponding
to the other
side of
the bobbin, and
then the
computer
changes
direction of
the traverse
motor only to
move
the traverse
assembly back
to the
beginning of
the pickup
bobbin.
I
am reusing
this photo to
show how this
new infrared
LED sensor and
stepper motor
system works.
In this
original
1940's 'gear
and cam'
setup, every
time the main
motor rotates
one rotation
the
mainshaft and
the pickup
coil rotates
once, the
'clock'
counter moves
one 'tick',
and the blue
timing
gear shown
in this photo
rotates once.
The blue gear
moves the
green and
yellow gears,
which
moves the red
heart cam, which
moves the
orange
traverse
assembly left
or right to
evenly wind
the
coil wire onto
the pickup's
bobbin.
In the Arduino
system, the
main motor
still moves
the mainshaft
and the pickup
coil you're
winding
and the
'clock' still
counts ticks.
However...
instead of the
heart shaped
cam we're
using a
stepper
motor, and
instead of the
blue main
timing gear
and its cam
drive we use
the silver
shutter shown
in the
other photos (mounted
where the blue
gear used
to be) and the
infrared LED
sensor to make
voltage
timing pulses the
Arduino can
count. The
Arduino counts
these pulses
and uses these
pulses to
control
the stepper
motor's speed
and direction,
main motor's
speed and
direction, and
shut itself
down when
the pickup's
coil is full. Depending
on the program
the Arduino is
running, any
type of coil
from a Tele
rhythm pickup to
a hot
humbucker or
even Jazz or P
Bass pickups
can be wound
with this
machine!
Best of all,
custom
modifications
to the pickups
(like reverse
winding or
overwinding/underwinding
the coil) can
be easily
programmed in
seconds!
