Bernina 900 User manual

* - A
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Al I
S* S
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Contents
General
information
2
Initial adjustment
operations
4
The needle .. . . .. . . . 5
Needle spacing in the stitch hole
. .. 6
Adjusting the
scanner .
.. 7
Scanner lift
.a... . . .. . 8
Adjusting
the stitch position
L- C-
R
9
Centering the
zig-zag link on the
link spindle 10
Neutral
position
of the needle
12
Lateral needle movement
13
Zig-zag stitch position
.
14
Lateral motion of needle
during zig-zag
and
plain stitch sewing .1.. .
15
Adjustment of the zig-zag width
4,5 mm. . 16
Adjusting the zero
position of the stitch
length crank
16
Adjusting buttonhole
without thread. . 18
Adjusting the
forward and reverse beads 19
Adjusting
the CB shuttle . . . . ....
20
Adjusting the return motion
. ... . . 21
Loop lift
22
Needle height
.,.. .. 23
Lateral
shuttle adjustment
24
Thread guide plate - .
24
Material
feed
25
Feed
dog height . . . . . . . ...
25
Feed dog movement
(Vertical) 26
Presser foot bar - --
27
Upper
thread tension - .
29
Lower thread
tension-
31
Adjusting
the thread regulator spring
32
Foot pressure
33
Winder
34
Retightening the drive belt .
35
Electrical
section - .
36
Adjusting Motor speed .-.. . . .
36
1

Type 9 Z Zig-zag and plain stitch sewing machine
electronic with 6 built-in cams and automatic button-
holer with 5 built-in cams.
Valid for model 900 electronic
trom machine no. 19 200 551
_n _
314 178 Fig. 1
Max. zig-zag width 45 mm
Stitch distribution: Left-Center-Right
Max. forward stitch length 4 mm
Max. reverse stitch lengeh: 2 mm
Presser toot lift: 6.5 mm
Passage space: 105 x 200 mm
Base plate dimensions: 374 x 178 mm
Shuttle system: Jam-free central bobbin shuttle
Bobbin capacity: 75 m cotton yarn
Needle system: 705 B
Needle movement, Swinging needle bar
Thread teed: Hinged take-up lever
Thread tension: Upper thread tensioner in frame
Built-in
Winder: Built-in
Motor Power. 90W
Sewing lamp (built-in) Power- 15W
Number of stitches: Approx 1100 stitches min
Weight (complete) 10i5 kg
2

Setting
needle:
=
705 B-80
Needle deflection:
With
lifting bar
suspension:
2
Needle
plate upper edge:
4.5
At
shuttle
tip: 463
Needle
bar
stroke:
V
33 73
Loop
stroke:
left
1 8
Shuttle
travel:
220
18' 30
Rack
travel:
34.6
Lift
crank
radius
17 3
Take-up
lever travel:
= 61
Presser
foot
lift:
= 6.5
Darner
stroke:
2,92
Speed:
Motor:
7400
rpm
Cone
pulley:
= 2372
rpm
Frame
shaft:
= 1120
rpm
Gear
ratio:
Overall:
6.6
1
Motor:
Cone
pulley
312
1
Cone
pulley: spindle
2,12
1
Base circumference:
245
mm
Machine
dimensions:
Overall
length:
= 399 mm
Overall
width:
178
mm
Overall
height:
350.5
mm
8
12
13
14
16
; 4
22
21
20
Fig
2
3

Initial adjustment operations
Rotate zig-zag knob (13) to postion (0)
Unscrew mounting screw knob (13) and
rF_ emove knob, Set slihch selection knob
(14)
to position (A) -------
Unscrew the
assoc ated
mounting screw
and remove
t * _ 14 _
Knob and scale
together with wheel,
13 i #^i _ gUnscrew both Phiillips screws (130) and
-lr
\ renmove cover
plate (129),
The screws are
riot visible
until knobs (1:.) and (14) hav
been removed Remove frame cover (128)
and end cover
(5) (Light switch
has been
switched ,on>.n
U Temporariy
reinsert zig-zag
krob (13) and
stitch selection knob (14) together with
scale,
r g, 3
Adjustments
can
now be carried
out
After adjustments have been made rein-
sert parts in reverse order.
IMPORTANT: The sewing machine can be
completely adjusted
and sewn oft prior
to mounting covers
14
128 14 Adjustment of the type 900 sewing
5
,
machine
: |
m <:: land other
rnodels)
13 .hese
adjustmen
instructions
are des:g-
Li
ned to assist
mo minor
repairs or
adjust-
130
-
ments of the
BERNINA sewing
machine
~~ 129 f Ol o f ~~tPe 900.
129
tMPORTANT:
The
sewing
mach
ne
must
be in perfect
mechanical
condition
(run-
{ning smoothly.
properly
oiled
etc.) so
tha!
idividual adjustments
can be
carried
out correctly,
-__________________ - If the sequence of adjustments is obser-
ved r peccable
speration
ot the machine
he
onsured

The needle
The needle is one of the most important BERNINA uses the "705 B,, needle system
elements of the
sewing rnachine.
It pier- without fluting
(Singer designation:
15 xl1
ces the fabric
and forms
a loop which
is on
all domestic
sewing machines
with
caught
by the
shuttle and is
joined with
CB-shuttle
hook.
the lower
thread
The loop is
formed after
The metric
system
has been
in unse since
the needle has
pierced the
fabric and has
1947 for needle
thickness designation.
A
reached its
lowest point.
The needle lifts
needle thickness
of 100 means
that the
slightly during the so-called
loop ift needle stem
is 1 mm thick.
The
tightly drawn
thread
which lies
in the (A
No.80 needle
- 0,8 mm:)
long and short grooves
on the front and
The needle must be
firmly secured by the
rear side
of the
needle, respectively,
is knurled
screw
on the needle holder.
caught above the short groove between
the needle
stem and the material, When IMPORTANT:
Always use a No 80 needle
the needle moves upward,
the thread feed for all adjustrnents unless otherwise sta-
is retarded
due to the
friction of
the ted,
Check the
needle prior
to every
ad-
fabric and thereby
a loop. comming from justment of the sewing machine. It must
the
needle eye, is formed on the rear side
always be straight.
of the needle This loop is caught by the
shuttle
tip, widened, and is guided
around
the lower thread supply. The important
features
of the sewing
needle are:
a) shank
for securing
the needle
in the
needle bar
b) stem with
a short and long groove
c) needle eye
d) needle point
e) needle
length
b
d Fig 5

Needle spacing
in
the stitch hole
The rieedle
must penetrate the
center of
the stitch
hole (as viewed
from the direc-
tion of fabric
feed) (needle thickness:
Fig 7
0~~~~
*1
I
most be removed.
Then, loosen
two
of the,
I
three
frame mounting
screws
(Allen
fl51
screws
with an interior
hexagon
width ot
vmm)
an.d move
the machirie
frame urnt
f
the needle
penetrates
the center ot
the
ASt ch
hole. Rotghilen
A: le
r, w Gi
i Fig.
S
6

Adjusting
the
scanner
to
the
center Rotate
handwheel
until
scanner
(119)
isat
of
cam
S
(Running
stitch)
by dis-
the
highest point
of
cam
(120).
Loosen
placing
the
adjusting
drum
mounting
screws
(121)
of
the
adjusting
drum,
Position
the scanner
precisely
in
Set
zig-zag
knob
(13)
to
position
"4-
and
the
center
of
cam
(5)
by
axially
moving
stitch
selection
knob
(14)
to
cam
adjusting
drum
(122)
and retighten
mount-
(D)
ing
screw
(121).
Check
also
the
front
and
rearmost
cam,
:, .
<:D tR l~~~~~~22
4
*__9 12l0
W
129 r
0
138
137
139
Fig 9
::___
127
124
123
~~U ¼
fI |
Fig.
10
7

Raising the
scanner Position
of
lifting
cam
The
scanner
i 19)
is raiset
sjn
the
if
When
the
scanner
(tl9i
is
at
the
inwest
camri
l123K
which
is fitted
c)'
he
.pinidle
poirt
of
the
zigzaq
eanm
there
mus
the
a
below
the
arLjusting
drunm
in f
Ii" gng
illi
little
play between
lifting
arm
124I
and
lt.
i124)
which
is
ad)iustabIe
an
nconnecter
ting
carn 1123)
to the cam
control lever the
play can
he observed by
Lrriiq the
The
lting
arm
124i
is Idlius't
f - as
toilows
stitch
selector
knob
tl4i
gently
iL-and
-ro
Set
z gzag
arijusting knob
( .;
to posit
on
bur;ng
this checs.k
it is
convenient
to
press
.4
and
scanner
to
highest
point
of
zigzag
the
cam
control
leve,
1125)
against the
ziy-
cam.
Place
a 01
15
mm
space,
'12b
be'-
zag
camn
If
no
play
s
apparent
at the
ween
Scanner
and cam
Sel
stit-
h'selector
stitch
selector
knob
(14), correction
shoulcd
knob
(14)
between
zigzag
and biindstitch
be made
as
follows
t oosen
fixing
screw
1127)
or
lifting
arm
loosen
screw
1162i
The
control
sponrig
124)
Fhis
is
drawn
to
the iilting
cam
(123t
it61i
(see
Fig
ila)
can
then
be displaced
by
Ihe
liftinq
arm
tension
Tsprn
'200,
lhe
sideways
until play
can
he observed
at
the
fixing
screw
i127)
is
then retigetened
stitch
selector
knob
14.
Re-tighten
screw
1162)
I
ig
tig.
K
_a;i _ i f U