Husqvarna Viking Automatic 21 User manual

SERVICE
MANUAL
for
VIKING
home
sewing
machine
class
21

Table Of Contents
Page
1 Adjust the machine for straight stitching
1 Timing the needle swing
2 Setting the presser bar height
3 Centering the needle in the throat plate hole
3 Setting center position for zig-zagging
3 Tangential adjustment of sewing hook
4 Setting needle bar height
4 Setting clearance between sewing hook and needle
5 Setting the feed dog height
6 Timing the feed
6 Lateral setting of the feed dog
6 Setting the thread giver
7 Setting the take up spring tension
8 Changing camshaft drive belt

1
.
Adjusting
the
machine
for
straight
stitching
staff
(
1
Fig
.
1
)
at
0
,
and
turn
the
Set
the
needle
swing
control
on
starting
-
position
control
to
the
right
.
Adjust
lever
(
2
Fig
.
1
)
to
obtain
minimum
play
between the
high
point
of
a
cam
and
the
follower
(
3
Fig
.
1
)
.
This
setting
should be made
with
the
stitch
selector
at
5
.
Loosen
screw
(
5
Fig
.
1
)
with
a
screwdriver
(
4
Fig
.
1
)
and
tighten
it
after
making
the
setting
.
Fig
.
1
.
2
.
Timing
the
needle
swing
Set
the
needle
swing
control
for
maximum
stitch
width
.
Turn
the
worm
gear
(
1
Fig
.
2
)
on
the
camshaft
,
pertaining
to
the
zig
-
zag
drive
,
until
the
left
-
hand
and
right
-
hand
movements
of
the
needle
-
bar
frame
(
3
Fig
.
3
)
terminate
when the
tip
of
the
needle
is
more
than
V
32
in
.
(
7
mm
)
above
the
throat
plate
on
the
downward stroke
.
Loosen
screws
(
2
Fig
.
2
)
and
tighten
them
again
after
making
the
setting
.
1

4
.
Centring
needle
in
throat
plate
hole
Set
the
needle
swing
control
for
maximum
stitch
width
.
Turn
eccentric
(
1
Fig
.
3
)
on
the
needle
-
bar
frame
(
3
Fig
.
3
)
,
which
serves
as
bearing
for
link
(
4
Fig
.
3
)
from
the
zig
-
zag
drive
,
until the
needle
swings
in
the
throat
plate
hole
with
equal
clearance
on
both
sides
when
the
hand
-
wheel
is
turned
.
Loosen
set
screw
(
2
Fig
.
3
)
before
making
the
settling
,
and
tighten
it
afterwards
.
Setting
centre
position
for
zig
-
zagging
Set
the
starting
-
position
control
at
the
centre
position
and
the
needle
swing
control
at
0
.
Loosen
screw
(
1
Fig
.
4
)
,
and make
the
setting
by
pressing
or
easing
follower
(
2
Fig
.
4
)
until
the
needle
is
centred
in
the
throat
plate
hole
.
5
.
Tangential
adjustment
of
sewing
hook
Set
the machine
for
straight stitching
in
the
right
-
hand
starting
position
,
and
for
a
zig
-
zag
stitch
5
/
u
in
.
(
2
mm
)
wide
.
Use
the
handwheel
to
bring
the needle about
s
/
64
in
(
2
mm
)
above the lower
end
of
the
stroke
on
the
way
up
.
Loosen
the
bevel
gear
(
1
Fig
.
6
)
on
the
lower
camshaft
and
screw
it
fast
again
in
such
a
position
that
the
tip
(
1
Fig
.
5
)
of
the
sewing
hook
comes
in
line
with
the
centreline
of
the
needle
(
2
Fig
.
5
)
.
The
arm
sleeve
must
be removed
for
this
setting
.
6
.
3

10
.
Timing
the
feed
This
setting
is
easiest
to
make
with
the
machine
set
tor
maximum
stitch
length
.
The
feeding
of
the
cloth
should
stop
just
before
the
needle
goes
down
into
it
,
when
sewing
both
forwards
and
backwards
.
To
adjust
,
turn
eccentric
(
S
-
11574
Fig
.
9
)
on
the
camshaft
'
.
Loosen
screw
(
1
Fig
.
9
)
to
make
this
setting
,
and then
tighten
it
again
.
11
.
Lateral
setting
of
the
feed
dog
Turn
lever
(
1
Fig
.
7
)
on
its
shaft
(
2
Fig
.
7
)
.
Loosen
screw
(
3
Fig
.
7
)
for
this
setting
and
tighten
it
again
afterwards
.
12
.
Setting
the
thread
giver
This
setting
is
made
by
turning
the
thread
tensioner
.
Open
the
face
plate
first
,
to
get
at
the
screw
at
(
1
Fig
.
10
)
,
which
holds
the tensioner
.
Loosen
the
screw
and
turn
the
tensioner
with
a
screwdriver
as
shown
in
Fig
.
10
.
6

14
.
Changing
camshaft
drive
belt
Take
off
the
belt
guard
on
the
end
of
the
machine
.
Take
out
the
re
-
duction
gear
,
raising
it
enough
to
get
it
free
of
the
belt
(
3
Fig
.
12
)
.
Re
-
move
the
screw
in
the
centre
of
the
handwheel
(
1
Fig
.
12
)
,
which
holds
it
to
the
camshaft
.
Draw
out
the
handwheel
from
the
machine
,
sliding
the
loose
belt
(
3
Fig
.
12
under
the
wheel
in
towards
the
centre
of
the
machine
on
both
sides
,
so
that
the
handwheel
and
belt
can
come
out
through
hole
(
2
Fig
.
12
)
in
the
sew
-
ing
head
.
To
replace
the
handwheel
and
belt
,
proceed
in
the
opposite
manner
.
Place the
new
belt
in
the
belt
groove
on
the
handwheel
;
slide
the
free
end
of
the
belt
into
place
,
holding
the
free
section
of
belt
on
the
underside
of
the
wheel
in
to
-
wards
the
centre
of
the
machine
.
8