JUKI MBH-180
 High-speed, single-thread, chainstitch, decorative buttonholing machine
MBH-18C
igh-speed, single-thread, chainstitch, label attaching machine
MBH-180L
No. IT-9
1991. 11
PREFACE
This Engineer’s Manual is written for the technical personnel who are responsible for the service and
maintenance of the sewing machines. This manual describes “How to adjust”, “Results of improper
adjustment’ and other functions which are not covered by the Instruction Manual intended for the
maintenance personnel and sewing operators at a sewing factory.
When performing maintenance of this machine, refer to Instruction Manual and Parts List as well as this.
Engineers Manual.
The Engineer's Manual consists of two parts; the former part presents illustration and simplified
explanation; and the latter part provides “Results of improper adjustment” in which sewing and/or
mechanical failures are described and “How to adjust” in which the adjusting procedures are explained.
CAUTION
1. Don't put your hand under the needle when you 2. Don't put your hand into the thread take-up
turn “on” the power switch or operate the machine. cover while the machine is ru nning.
OFF ON
ae
3. Don't forget to cut off the power supply before you tilt the machine head backwards or replace the V-belt.
4. Never bring your fingers or hair close to,
or. place anything on the handwheel,
V-belt, bobbin winder wheel or motor during operation,
5. If your machine is provided with a belt cover,
It may lead to serious personal injuries,
finger guard and eye guard, never operate your machine
with any of them removed.
CONTENTS
1. SPECIFICATIONS aaa enaaranomanena vano rerxi roda, 1
2. STANDARD ADJUSTMENT . o.oo ee ee ee AA RAA A A LE 2
(1) Adjusting the needle bar height . .. ... 0 aaa aaa enoreaaró 2
(2) Adjusting the needle entry point for the needle bar rockingmotion . .................. FE 2
(3) Adjusting the looper timing . .................. ee rene noudreñderd%ecenar, 4
(4) Adjusting the thread tension release mechanism .............. e a are, 8
(5) Adjusting the gears in the vertical stroke of the needle bar ............. 2... eee 8
(6) Adjusting the gear of the feed cam ................ 0... A ALL LL 10
(7) Adjusting the feed brake . ............. ere aanacocaanoreeoedio, 10
(8) Adjusting the feed conversion block .............. e... e... .. PE 12
(9) Adjusting the position of the feed conversionblock ................... JE eee Le 12
(10) Adjusting the clearance between the throat plate and the work clamp foot receiving plate ........... 14
(11) Adjusting the worm 112211111204 dd AA A A LA AAA AA LS 16
(12) Adjusting the bartacking rocker arm stopper .............. 0... ALL 11 18
(13) Adjusting the brake of bartacking groove cam '................ AA 0 18
(14) Adjusting the positioning screw ......... ee ee ee 20
(15) Adjusting the link spring of the change-oeverlever ................ A LL LL 22
(16) Adjusting the knife dropping position (MBH-180) .......... 2.2 00rareoaea, eee 22
(17) Adjusting the lifting amount of the work clamp foot .............. erre 24
(18) Adjusting the starting arm and presser tripping bracket ......... PA 24
(19) Adjusting the stop-motion trippinglever .............. 6.000 a aaeoereran, 26
(20) Adjusting the position of the stop-motion bracket ................. PS PS 26
(21) Adjusting the stop-motion presser adjustment SCIEW . . . co. ooo vse soso es 28
(22) Adjusting the clutch actuatingarm ......... LL... a a eaoraaradió, 28
(23) Adjusting the thread trimming cam and the thread trimming link 11010111 LL LL LL LL 30
(24) Adjusting the re-startingarm ............. a aaa aaa oarrererean, 2... 32
(25) Adjusting the emergency stop mechanism ....................... ee, 32
<Adviceinpoint> ....... LL. aa LL La 1 PT 34
- 3. TROUBLES AND CORRECTIVE MEASURES ............e 0.00 a000uaareoea, ERE ET 35
4. DRAWING OF THE TABLE .. . eee 43
1. SPECIFICATIONS
1 | Model MBH-180 MBH-180L MBH-180S
High-speed, single-thread, High-speed, single-thread, High-speed, single-thread,
2 | Name Chainstitch, buttonholing chainstitch, label attaching | chainstitch, decorative
machine machine buttonholing machine
For buttonholing shirts, For sewing labels and For decorative button-
etc. bartacking holing.
3 | Application 7
PODA
383
4 | Sewing speed 3,300 s.p.m.
1/4" (6.4 mm) to 7/8”
14" € (22.2 mm)
1/4” (6.4 mm) to 1/4" (6.4 mm) to (Seam as long as 1-1/2"
> | Seam length 1-3/8" (34.9 mm) 1-1/2" (38.1 mm) (38.1 mm) can be sewn by
replacing the work clamp
foot.
6 | Needle DB x 1 #11 to #16 DB x 1 #11 to #14 DB x 1 #11 to #16
7 | Zigzag width | 1.6 to 2.4 mm (sewing possible area)
8 | Needle bar stroke 27 mm |
9 | Looper mechanism A pair of loopers (right and left) makes both-direction stroke
10 | Thread take-up Modified-shape needle bar thread take-up
mechanism
11 met adjust- By slit-slide method
Stitch length adjust- ee
12 | ing method By slit-slide method
13 | Stitch length 0.4 to 1mm ANA
14 Thread t mé Thread is trimmed by the counter knife and the thread spreader.
15 pork camp foot By the auto-lifter or the hand lifter
Max. 7 mm (normal : Smm)
16 | Lifting amount of Max. 2 mm Max. 7 mm
the work clamp foot (at the front end position) | (normal : 5 mm)
'
17 | Lubrication By an oiler
18 | Standard dimensions 470 mm x 212 mm x 163 mm
19 | Machine head weight 42 kg
20 | Motor 3-phase, 200 W, general-purpose motor
21 | Noise 90 dB or less when sewing the parallel section of buttonhole
2. STANDARD ADJUSTMENT
Standard adjustment
(1) Adjusting the needle bar height
When the needle bar is in the highest position of its stroke, a distance of 8.5 mm should be provided
between the top surface of the throat plate and the top end of the needle.
Fig. 1 Fig. 2
(2) Adjusting the needle entry point for the needle bar rocking motion,
Standard
adjustment MBH-180S : 2.4mm * Standard adjustment of the ACF-182 is 2 mm.
| MBH-180 :2 mm
MBH-180L © 2.4mm
Needle bar frame
fd Whee ="
+
How to adjust
Results of improper adjustment
Place a timing gauge on the throat plate as illustrated in Fig. 2, and
bring needle bar @ to the highest dead point.
Loosen needle bar connection screw @ , and adjust the height of
the needle bar as illustrated in Fig. 2 by placing needle clamp screw
© in the direct side-to-side center of the slit taking care not to
allow the screw to come in contact with the slit edge as illustrated
in Fig. 3.
„| |» @ Needle clamp screw
Fig. 3
té tr
1. Changing the needle bar height affect
the looper timing, resulting in stitch
skipping or loose stitches. So do not
change the needle bar height.
2. Avoid adjusting the needle bar height
using the clamping screw @ in the
needle bar lifting shaft. Doing so
may change the stroke of the needle
bar.
1. Remove the throat plate, and put the timing gauge in the throat
plate installing groove. Align the needle entry point for the
front stroke with the marker line engraved on side @ of the
timing gauge. To adjust the needle entry position, remove the
top cover, loosen clamping screw @ in the frame rock shaft
crank and perform the adjustment.
2. Adjust the stitch bite width by raising/lowering needle bar
frame rock link ® in the slit on needle bar frame drive
adjusting crank Q so that the needle tip is aligned with the
marker line engraved on side of the timing gauge at the
needle entry for the rear stroke.
3. The aforementioned adjustment should be carried out while
making the machine run in the nognal direction. If you
allow the machine to run both in the normal and reverse
directions when you perform the adjustment, you may not
able to obtain the correct needle entry point.
- Direction A:
Stitch bite width is decreased.
Direction B:
Stitch bite width is increased.
i
Rear stroke / \ Front stroke:
Fixed to a constant value
Fig. 6
1. Changing the stitch bite width changes
the looper-to-needle timing. So when-
ever you have changed the stitch bite
width, also adjust the looper timing
without fail.
* Do not use clamping screw @ in the
needle bar frame drive adjusting crank
to adjust the needle entry. Use clamp-
ing screw @ in the needle bar frame
crank to adjust it. Adjusting the
needle entry using clamping screw
@ may cause an axial play.
Standard adjustment
(3) Adjusting the looper timing
1} LooperNo. 1
(the looper located on the right-hand side as observed from the front side of the machine) 8.2 mm
LooperNo. 2 each
(the looper located on the left-hand side as observed from the front side of the machine)
4
©
= 8 / PS
8.2mm — —
| 1 A O Ÿ 8.2mm
Fig. 7 Fig. 8.
2) Adjusting the looper No. 1
(1) Make the looper come in contact with plane (2) Clearance between the needle and the
A when the looper is in its rear end. looper point
Plane A
S
Fig. 9 | Fig. 10 |
(3) When the looper point is aligned with the side @ The needle drops behind the looper
of the needle when the laoper scoops the thread
Looper No. 1 : 0
Aligned
0.1—0.2mm
G,
cs
J & %
Fig. 11 The position where the needie does not Fig. 12
& come in contact with the looper.
0 to 0.5 mm
How to adjust
Results of improper adjustment
I. Adjusting the inclination of the loopers
Use a timing gauge for this adjustment.
The loopers No. 1 and No. 2 can be adjusted following the same
adjusting procedure.
Fitlooper @ first in looper mounting base @ shown in Fig. 8,
and temporarily tighten screw @ .
Then, place timing gauge ® on a flat board as illustrated in
. Adjusting the looper No. 1
D Position of the looper with respect to the direction of
rotation
Fit looper mounting base @ in looper shaft @ , and set the
timing gauge on the machine bed as illustrated in Fig. 9.
Then press the top end of the looper against plane A of the
timing gauge when the looper is in its rear end, and tempora-
rily tighten screw @ .
2 Adjusting the clearance between the needle and the looper
When the looper travels forward until it is positioned as
illustrated in Fig. 11, adjust the clearance between the needle
and the looper to 0.05 to 0.1 mm. Then securely tighten
the screw in the looper mounting base.
(3 Adjusting the looper when it scoops the thread
Loosen two screws @ shown in Fig. 13.
If the distance between the needle eyelet and the looper is
too large, loosen the screw No. 2 and tighten the screw No. 1.
On the other hand, if the distance between the needle eyelet
and the looper is too small, loosen the screw No. 1 and
tighten the screw No. 2. After the looper is correctly
positioned, firmly tighten the two screws. Do not forget to
tighten screws @ .
© —
D
D Screw No. 2
\
y
Screw No. 1 Fig. 13
2 Adjusting the position where the needle drops behind the
looper
Adjust the position where the needle drops behind the looper
simultaneously with the adjustment of the position of the
looper at the time of scooping the thread.
1. If the inclination of the looper is not
adjusted with accuracy, the thread
may fail to come off the looper,
resulting in stitch skipping or poorly
tensed stitches.
2. Be sure to use a timing gauge when
adjusting the position of the looper
with respect to the direction of rota-
tion. If not, the position of the looper
when scooping the thread cannot be
adjusted with ease in the next step of
adjustment.
3. Stitch skipping may result.
Minimize the clearance between the
needle and the looper when using
light-weight materials or elastic
materials as long as the looper does
not come in contact with the needle.
* If the blade point of the looper No. 1
fails to scoop the loop of thread:
at... Sewing direction
* If the needle fails to drop behind the
looper No. 1:
Sewing direction
“jj
Standard adjustment
3) Adjusting the looper No. 2
(1) Press the looper No. 2 against plane B when (2) The clearance between the needle
the looper is brought to its back end. . | and the looper point
¡ 0.05—0. (mm
Fig. 15
(3) When the blade point is aligned with the (4) The needle drops behind the looper
side face of the needle when the looper
scoops the thread
Aligned | Looper No. 2
0
0.1—-0.2mm |
The position where the needie does
not come in contact with the looper
Fig. 16
Fig. 17
How to adjust
1. Adjusting the looper No. 2
(1) Position of the looper with respect to the direction of
©
rotation
Fit looper mounting base @ in looper shaft @ , and set the
timing gauge on the machine bed as illustrated in Fig. 14.
Then press the top end of the looper against plane B of the
timing gauge when the looper is in its rear end, and tempora:
rily tighten screw ©.
Adjusting the clearance between the needle and the looper
When the looper travels forward until it is positioned as
illustrated in Fig. 16, adjust the clearance between the needle
and the looper to 0.05 to 0.1 mm. Then securely tighten the
screw in the looper mounting base.
Adjusting the looper when it scoops the thread
The position of the looper No. 2 is automatically determined
since the looper No. 1 has already been adjusted with respect
to the looper position when the looper scoops the thread.
If the looper No. 2 is not properly positioned, re-adjust the
position of the looper No. 1 when the looper scoops the thread.
If the looper No. 2 cannot be properly positioned even after
~ the re-adjustment of the looper No. 1, replace the looper
< Looper No. 1 mounting base >
mounting base. If you do not have a looper mounting base in
stock, provide a clearance between the looper No. 2 and the
looper mounting base to adjust the position of the looper
No. 2.
LO Dimension a 3 95m
Dimension a
3.85mm
4.05mm
4.15mm
< Looper No. 2 mounting base >
Dimension b (ON Ci
| v
(Caution)
e)
|
}
Dimension b
3.75mm
3.85mm
3.95mm
| 4. 05mm
atl
а
— 4.15mm
\
Fix the looper while providing an approximately
! 0.1 mm clearance between the looper and the
mounting base.
Part No.
B2521180B00
B2521180C00
B2521180D00
B2521180E00
Part No.
B2522180A00
B2522180B00
B2522180C00
B2522180D00
B2522180E 00
If the clearance between the looper and the looper
mounting base is too large, durability of the looper
may be impaired. So do not provide too large
clearance between them,
To prevent stitch skipping, it is quite necessary for you to
correctly positioned the loopers by performing the afore-
mentioned adjustments.
The position where the needle drops behind the looper
Adjust the position where the needle drops behind the looper
simultaneously with the adjustment of the position of the
looper at the time of scooping the thread.
Results of improper adjustment
1. Be sure to use a timing gauge when
adjusting the position of the looper
with respect to the direction of
rotation. If not, the position of the
looper when scooping the thread
cannot be adjusted with ease in the
next step of adjustment.
2. Stitch skipping may result.
Minimize the clearance between the
needle and the looper when using
light-weight materials or elastic
materials as long as the looper does
not come in contact with the needle.
* If the blade point of the looper No
fails to scoop the loop of thread:
Sewing direction
р-не
| КОСО
— нь»
* If the needle fails to drop behind the
looper No. 2:
Sewing direction
——s;—.—
.2
Standard adjustment
(4) Adjusting the thread tension release mechanism
The tension disk floats while the machine is performing bartacking to prevent the thread from being
tensed.
Adjust, when the sewing machine is sewing the parallel sections of a buttonhole, so that a clearance of
0.5 to 0.8 mm is provided between thread tension release pin @ and thread tension release arm @
as illustrated in Fig. 19.
8
=D Thread tension release arm
/ “
0.5—0.8mm
(
| <
y
| oi] ;
b Thread tension
release pin
10 O Do
NU 7) Fig. 19
Fig. 18
(5) Adjusting the gears in the vertical stroke of the needle bar
— Each of the gears used to control the vertical stroke of the needle bar has an engraved marker dot as
illustrated in Fig. 20. Fix the gears with the engraved marker dots aligned.
‘Screw in the gear
| 7 Gear ' é
LAG
JT
EL
Driving shaft a
Engraved
marker dots
=
Fig. 20
V groove
How to adjust
Results of improper adjustment
1. Let the feed mechanism actuate on the parallel section of a
buttonhole.
2. Adjust so that a clearance of 0.5 to 0.8 mm is provided between
thread tension release arm @ and thread tension release pin @.
Then tighten the clamping screw of the thread tension release
arm. At this time, carefully eliminate an axial play in thread
tension release shaft ©.
1. If the clearance between the thread
tension release arm and the thread
tension release pin is too large, the
thread tension release mechanism
will not work. In this case, bartack
stitches may be pulled resulting in
deformed bartack stitches (bartack
stitches will be gathered).
On the contrary, if the clearance is
too small, the tension disk will be
released in the case other than
bartacking, resulting in poorly tensed -
stitched in the parallel section of a
buttonhole. |
1. Align the engraved marker dots on the respective gears used to
control the vertical movement of the needle bar. Then tighten
the screw No. 1 (longer screw) with aligned with the V-groove.
2. Bring the sewing machine to its stop-motion position, and
confirm that the needle bar is in its highest dead point.
(Caution) It is difficuit to remove the two screws in the gears
since they have been applied with locking agent.
If you would remove the screws in the gears, be sure
to retighten the screws applying locking agent on
them.
If the screws are not locked, they may fluctuate after
a long time usage of the sewing machine.
. If the engraved marker dots on the
gears are not aligned with each other,
adjustments of the sewing machine
including the adjustment of looper
timing will be adversely affected.
So be careful.
Standard adjustment
(6) Adjusting the gear of the feed cam
Adjust the gear of the feed cam so that the engraved marker dot on the gear is aligned with the engraved
marker dot on the gear of the looper driving cam as illustrated in Fig. 22.
Gear of the looper
driving cam
Engraved marker dot on the
gear of the looper driving cam —
Engraved
marker dot
y
Engraved marker dot on 7
the feed cam gear ,
Fig 23 e Fig, 24
(7) Adjusting the feed brake
Minimize the pressure of the feed brake as long as the feed case © does not turns both clockwise and
counterclockwise but turns only in the single direction, when turning the machine by hand.
— 10 —
How to adjust
Results of improper adjustment
1. Loosen two screws @ in the feed cam shaft (a screw is tightened
in the lower section of the shaft) and feed cam shaft thrust collar
@ . Then, feed cam shaft € can be removed.
edge of feed cam.
When feed block O in feed converting shaft @ is brought to
the highest dead point, the needle and the looper blade point
will come to the standard adjustment position.
. Tighten feed cam shaft thrust collar @ providing a 0.5 mm
clearance between the edge of the looper driving cam and
1. If the engraved marker dot on the
gear of the feed cam is not aligned
with the engraved marker dot on
the gear of the looper driving cam,
the timing between the looper
and the needle will be adversely
affected. So be careful.
Adjust the pressure of feed brake @ using brake spring nut ®
(double nut).
If the stitch length is shortened at
one section of a seam or is not
uniform, further increase the pressure
of the feed brake.
Irregular stitches
— 11 —
Standard adjustment
(8) Adjusting feed conversion block
When feed conversion block O is brought to its leftmost point, a clearance of 1 mm should be
provided between the feed mechanism and the conversion block.
Conversion block cover \ e
| MM © Connecting rod
Fig. 26
(9) Adjusting the position of the feed conversion block
(Adjusting the feed pitch for the first line and second line of the parallel section of a buttonhole)
—
Jim
|)
Fig. 29
If the feed pitch for the first line of the parallel section of a buttonhole is not equal to that for the
second line of the parallel section of the buttonhole, adjust the feed pitch by turning feed
conversion shaft @ . |
Second line
\ (a)
(Good) (Not good)
In the case of (a), tum @ in the
direction of the arrow.
Fig. 30 In the case of (b), turn & in the
direction of the arrow.
First line
—12—
How to adjust
Results of improper adjustment
~ Push or pull adjusting nut @ so that a clearance of 1 mm is
provided between the feed mechanism and the conversion block
when feed conversion block @ is brought to the leftmost
position of its stroke
< For the MBH-180S, MBH-180L > < For the MBH-180 >
Fig. 27
Part No. D1651180L00
Fig. 28
Part No. B1651180000
‘illustrated in the figure.
—l— nt)
The feed conversion block has grooves as
The direction of rotation of the clutch
changes in accordance with the groove
positions. If the feed conversion block is
not properly adjusted, the clutch timing
will change resulting in a feeding failure.
1. Set feed joint O to 26 mm.
2. Loosen screw @ in the feed conversion arm, and adjust the feed
pitch properly by tuming feed conversion shaft @ .
If the feed pitch for the first line is smaller than that for the .
second line, turn the feed conversion shaft in direction .
If the feed pitch for the second line is smaller than that for the
first line, turn the feed conversion shaft in direction ©.
A red marker dot is engraved on the end face of the feed conversion
shaft and on the bed boss. These marker dots are used as reference
when positioning the feed conversion shaft. These marker dots are
aligned when the machine is sewing the first line of parallel section
of a standard buttonhole, or aligned when the machine is sewing the
second line of parallel section of a decorative buttonhole. So adjust
the position of the feed conversion shaft using the marker dots as
reference.
~ Engraved marker dot
Fig. 31
Adjustment of feed conversion shaft @
is very delicate. If the shaft is turned by
2 to 3 mm, the feed pitch for the second
line will be larger than that for the first
line. So deliberately adjust the feed
conversion shaft.
—13—
Standard adjustment
- (10) Adjusting the clearance between the throat plate and the work clamp foot receiving
plate
(1) Frontend of the throat plate and the work clamp foot receiving plate
When work clamp foot receiving plate @ is in its back end, a clearance of 0.4 mm should be
provided between the receiving plate and throat plate @ .
©. [Tom
©
© ©
Fig. 32 Fig. 33
(2) Side face of the throat plate and the work clamp foot receiving plate
When the machine is sewing the second line of parallel section of a buttonhole, a clearance of
0.6 mm should be provided between work clamp foot receiving plate @ and throat plate @ .
o 0
A
›
<MBH-180>
Ole
ri
® ® |
Fig. 34
©
\ 7 0.6mm
Receiving mee 7 1 fu
Throat plate
Fig. 35
— 14 —
How to adjust
Results of improper adjustment
Determine the position of the work clamp foot receiving plate
using the feed plate stopper mounted on the reverse side of the
bed.
Adjust so that a clearance of 0.4 mm is provided between work
clamp foot receiving plate @ and throat plate @ using posi-
tioning screw @ . Then securely tighten nut @ .
e Îf the clearance between receiving
plate @ and throat plate @ is
smaller than 0.4 mm, receiving plate
© may come in contact with throat
plate @ , resulting in breakage of the
components.
If the clearance between receiving
plate @ and throat plate @ is
larger than 0.4 mm, the material may
enter the clearance between-them or
may flap. As a result, sewing will be
adversely affected.
Put bartacking cam roller @ of bartacking rocker arm @ on the
higher crest (the six protruded sections consists of five higher crests
and one lower crest) of bartacking feed cam O . Then, loosen
screw @ in forked part O of the rocker arm O , and move T
link €) up or down to adjust the clearance between work clamp
foot receiving plate @ and throat plate @ to 0.6 mm.
Then, place T link stopper @ lightly on the boss of T link @,
and firmly tighten screws @ .
* The shape of bartacking feed cam of the MBH-180 is different
from that of the MBH-180S as illustrated in Figs. 37 and 38.
Also note that the MBH-180L is not equipped with a bartack-
ing feed cam.
If there is a clearance between the T link
stopper and the boss, the feed plate may
overrun at the time of bartacking. Asa
result, bartack will be finished as
illustrated below.
Free
Overrun
—15—
Standard adjustment
(11) Adjusting the worm (adjusting the needle sway)
Move change-over lever @ in the right until it will go no further, and the bartackin g ratchet will
come off allowing the machine to perform bartacking.
Check the needle sway at the bartack section of a buttonhole.
Worm O is correctly positioned as long as the feed plate starts moving in the direction of the arrow
when the eyelet of the ascending needle is aligned with the throat plate surface.
<MBH-180, MBH-180L)
[x1 — 39
O
DE MD
des
Je
Fig. 40
— 16 —
How to adjust
Results of improper adjustment
1. Recheck the height of the needle bar.
(When the needle bar is in its highest dead point, the needle tip
should be positioned 8.5 mm above the throat plate surface.)
2. Loosen screw ® in the worm, and position worm O so that
the adjustment values described in “Standard adjustment” are
obtained.
3. Press driving shaft spacer O against worn Y so that the worm
comes in contact with needle bar frame cam @ . Then fix the
worm eliminating an axial play.
4. When adjusting the worm, the clearance between stop-motion
arm @ and driving cam € becomes 1 to 5 mm before the
machine enters the stop-motion state (when stop-motion arm о
moves above driving cam @ ) as illustrated in Fig. 43. Be sure
to confirm that the said clearance is provided between the arm
and the cam. Note that the clearance is desired to be smaller
from the mechanical point of view though the acceptable range
of clearance is 1 to 5 mm. |
4
7
/
/
©
Fig. 43
(Caution) When adjusting the worm, the MBH-180/-180L and the
MBH-180S is different in direction in which the needle
sways. So be careful, (See Figs. 41 and 42.)
Deliberately adjust the worm with accuracy.
to
. If the timing of needle sway is too
early, the sewing pattern shape will
be deformed. If the timing is too
late, the sewing pattern shape will
also be deformed through the well-
tensed seam will be obtained.
. If the timing of needle sway is
excessively early or late, the machine
may fail to enter the stop-motion
state or the stop-motion impact may
be excessive or stitch skipping may
result. |
. If stitch skipping occurs during bar-
tacking when using a throat plate of
which needle hole is 1.6 mm wide,
replace the throat plate with throat
plate of which needle hole is 1.2 mm
wide to prevent stitch skipping.
In this case, however, note that the
thread may be cut by the needle
(thread breakage during bartacking)
when using the throat plate with a
1.2 mm wide needle hole. So, when-
ever you have replaced the throat
plate with a 1.6 mm wide needle
hole with the throat plate with a
1.2 mm wide needle hole, check the
sewing machine performance for
thread breakage.
<ACF-182>
Throat plate 1.2 mm
Part No. 162-73708
Throat plate 1.6 mm
(The machine is equipped with this
type of throat plate at the time of
delivery.)
Part No. 162-73807
Throat plate 2.0 mm
Part No. 162-73401
yl nm.
This dimension changes according
to the throat plates.
—17—
Standard adjustment
(12) Adjusting the bartacking rocker arm stopper (only for the MBH-180)
When stop-motion shaft @ moves in the right until stop-motion tripping plate @ comes off
rocker arm stopper @ , the hook of rocker arm stopper @ will be placed on rocker arm
block @ .
This will determine the position of bartacking rocker am Q when the knife drops.
@ ©
Е à
© E Г
N К ESTE! )
OS (dD) D) ©
DUDO €
—— 38 AH -
N N — Te OE
N
©
Bartacking feed cam
о 9
Q 9
Fig. 44
(13) Adjusting the brake of bartacking groove cam
Adjust the pressure of bartacking brake € during bartacking so that bartacking groove cam @
follows the rotation of the worm.
se
©
©
/
Fig. 45
~ 18 —
How to adjust
Results of improper adjustment
Place bartacking cam roller @ on the lower crest among the six
crests of the bartacking feed cam, lightly press rocker arm block @
against the hook of rocker arm stopper @ , then temporarily tighten
screw @ . Then, securely tighten nut © using screw @ . Now,
firmly tighten screw @ which has been temporarily tightened before.
* The MBH-180S or -180L does not have a rocker arm stopper.
Consequently, the aforementioned adjustment is not necessary
for these models.
If the block is excessively pressed upward,
the machine may fail to start running or
bartack width may not be uniform {over-
run, etc.)
If the block is insufficiently pressed (the
clearance between the block and the
hook is too large), the bartack width will
not be uniform, either.
Adjust the pressure of the brake by loosening or tightening screw @ .
If the brake pressure is too high, defective
stop-motion may result. '
On the other hand, if the brake pressure
is too low, malfunction of sewing
machine, such as the machine enters the
stop-motion state while the machine is
in operation, may result.
—j19—
Standard adjustment
(14) Adjusting the positioning screw
Enlarged view as observed from O
<MBH-180 >
Feed plate @. comes in contact with feed plate stopper © immediately before the machine
finishes the second line of parallel section of a buttonhole. The standard relationship between
change-over lever @ and bartacking ratchet @ is obtained when they are overlapped with each
other by approximately 0.5 mm as illustrated in the figure below.
O
© o
NE В т
o
La | AE
1
0.5mm © ©
Fig. 46
< MBH-180L >
This machine does not perform bartacking. So, adjusting the positioning screw will change only
the sewing length.
< MBH-180S >
The sewing directfon of the MBH-180S is opposite to that of the MBH-180.
Changing positioning screw @ shown in Fig. 46 will change the needle entry of the first bartack.
So, position the positioning screw so that the troubles in sewing including stitch gathering, thread
breakage and stop-motion of the sewing machine do not occur during bartacking. The needle entry
at the sewing end is determined using positioning screw .
Sewing direction
=
” k | S y
First bartac Needle entry at the sewing end
Fig. 47
— 20 —
How to adjust
bee
Results of improper adjustment
|. Adjust the position of change-over arm © using positioning
screw @ mounted on positioning plate € . Once the change-
over arm has been properly positioned, firmly tighten nut @ .
2. Other positioning screw @ is used to determine the relation-
ship of the arrow and the graduations on the scale plate.
< Technical information to the point >
Model : ACF-182
Information on : Thread breakage in the bartack section of a
buttonhole
Phenomenon : :
| . The needle sticks in the thread
resulting in thread breakage.
3
5
Fig. 1 Needie entry point
diagram > 3 mm, standard value
y
=
Fig. 2
Corrective measure :
1. The throat plate of which needle hole is 1.6 mm wide is
currently used as standard. However, check whether the
throat plate is the standard type.
Part No. of the throat plate : 16273807
(If the throat plate with a needle hole of 1.2 mm wide, thread
breakage is likely to occur.)
2. Slightly decrease the thread tension during bartacking.
3. Check whether the standard value of 3 mm is provided as
illustrated in Fig. 2. (If the protruding amount of the screw
is not 3 mm, adjust so that the standard value is provided and
check the finished state of the seam.)
4. If the screw protrudes from the change-over lever by 3 mm,
tighten or loosen the screw by one or two threads to change
the change-over timing.
—]—Ú—[——[— À
< MBH-180 >
This adjustment is carried out to deter-
mine the sewing start position and the
needle entry at the end of bartack. This
is called the “separation of the first
stitch”.
If the clearance between the first needle
entry at the sewing start and the last
needle entry at the sewing end is
too large, move the positioning screw to
the left. If the clearance is too small,
move the positioning screw to the right.
Second bartack First bartack
Space is left. .
< MBH-180S >
Since adjustment @ in Fig. 46 changes
the timing of applying tension to the
thread at the first bartack, stitches may
excessively gather to make a lump of
thread or the needle may penetrate the
thread resulting in thread breakage.
Adjustment @ in Fig. 46 changes the
position of the last needle entry at the
sewing end. If bartack at the sewing end
is not made properly to prevent the
stitches from fraying, perform adjust-
ment @ . |
— 21 —
Standard adjustment
(15) Adjusting the link spring of the change-over lever
Maximize the pressure of spring as long as stitch gathering does not occur before starting bartacking.
e ©
| D
OD O
E |,
U- o ((D/
Fig. 48
(16) Adjusting the knife dropping position (MBH-180)
Adjust cloth cutting knife Q so that it drops the center of the knife slit on throat plate @ .
—272—
How to adjust
Results of improper adjustment
Change-over lever @ is designed to move to the left and right.
Link presser spring @ works to prevent the lever from moving
except in the case where it is necessary to move the lever.
Adjust the link presser spring properly by tightening/loosening the
nut.
If the pressure of the link presser spring
is too low, the machine may sew a
buttonhole that is smaller than the
normal size, the machine may fail to
perform sewing other than bartacking
- or the machine may enter the stop-
motion state during sewing. On the
other hand, if the pressure of the link
presser spring is too high, stitches may
gather before starting bartacking.
——
Remove first stop-motion presser adjustment screw @ to allow
cloth cutting knife arm @ to move freely.
Then, tilt the sewing machine away from you. Remove screw @
in the collar, and screw positioning collar @ of the cloth cutting
knife in the direction of the arrow.
Then, move cloth knife cutting knife shaft @ up or down to find
out a place where cloth cutting knife @ drops the center of throat
plate @ . Once the cloth cutting knife is properly positioned,
lightly press positioning collar @ of the cloth cutting knife
against the boss of the bed, and firmly tighten screw Q in the
collar at that position. |
* Since a cloth cutting knife is not attached to the MBH-180L or
-1808S, this adjustment is not necessary.
This adjustment greatly affects sharp-
ness and durability of the cloth cutting
knife. So, it is quite necessary to
perform this adjustment carefully.
Standard adjustment
{17} Adjusting the lifting amount of the work clamp foot
1. When the work clamp foot is in its lowest position, a clearance of 0.5 mm should be provided
between the work clamp foot mounting base and the lifter lever.
2. When the stop-motion bracket is in the highest position of its stroke, a clearance of 0.5 mm
should be provided between lifter stopper suspension @ and lifter adjusting block @ .
Fig. 52
Stop-motion bracket
Fig. 53 Highest position
(18) Adjusting the starting arm and presser tripping bracket
1. A clearance of 1 mm should be provided between the point marked with an asterisk ( * ) of
starting arm @ and the point marked with an asterisk ( * ) of thread trimmer guide arm @ .
2. Position presser tripping arm @ so that a clearance of 0.5 mm is provided between the tripping
arm and lifter adjusting block @ .
* Ciearance 1.0 mm
— 24 —
How to adjust
Results of improper adjustment
1. Depress the foot pedal at the stop-motion position of the sewing
machine to make work clamp foot Q come down. At this time,
adjust the clearance between work clamp foot mounting base
@ and lifter lever @ using adjustment screw @ provided
with lifter lever stopper @ . |
2. Then, bring the stop-motion bracket to its highest position as
illustrated Fig. 53. Adjust so that a clearance of 0.5 mm is
provided between lifter stopper suspension € mounted on
cloth cutting knife arm @ and lifter adjusting block @ .
Temporarily tighten screw O in the block, and determine the
position of the lifter adjusting block using adjustment screw () .
Once the block is correctly positioned, firmly tighten nut @
and adjusting screw © .
* For the MBH-180L, the lifting amount of the work clamp foot
is 2 mm when the clamp tail piece is in its front end.
0.5mm
<= Clamp tail piece in its front end
©
If the clearance between the lifter
stopper suspension and the lifter
adjusting block is smaller than 0.5
mm, the work clamp foot may fail to
go up at the time of stop-motion.
If the clearance is larger than 0.5
mm, lifting amount of the work
Determine the position of the starting arm by moving bumper
carrier 3 back or forth. Then determine the position of presser
tripping bracket € . Tighten the clamping screw to adjust so that
a clearance of approximately 0.5 mm is provided between presser
tripping bracket @ and lifter adjusting block : @ .
If there is no clearance between the
presser tripping bracket and the lifter
adjusting block, the work clamp foot
may fail to go up.
If the clearance between the bracket
and the block is too large, a higher
pressure will be required to operate
the starting pedal.
Standard adjustment
(19) Adjusting the stop-motion tripping lever
‘When the bartacking base turns counterclockwise until stop-motion tripping lever o comes in
contact with the square projection of stop-motion latch @ , the overlapping length of the stop-
motion tripping lever and the stop-motion latch should be 2.5 to 3 mm as illustrated in Fig. 56.
(20) Adjusting the position of the stop-motion bracket
When the sewing machine is normally in operation, a clearance of 0.05 to 0.1 mm should be
provided between drivingcam @ and stop-motion stopping shaft @ .
— ttf
0 a 0.050. mn
— 26 —
How to adjust
Results of improper adjustment
Adjust the stop-motion tripping lever by moving stopper screw @
of the stop-motion tripping lever up or down. Once the stop-motion
tripping lever is properly positioned, securely tighten nut @ .
If the overlapping length of the stop-
motion tripping lever and the stop-
motion latch is excessive, the machine
may fail to start running for the next
sewing,
On the contrary, if the overlapping
length is insufficient, the machine may
keep running without entering the
stop-motion state.
The position of stop-motion shaft @ is determined by stop-motion
latch @ and slide bracket @ . Consequently, the position of
stop-motion stopping shaft @ is determined.
Loosen screw @ , and adjust the position of stop-motion shaft @
using nut @ .
Adjust so that a clearance of 0.05 to 0.1 mm is provided between
driving cam @ and stop-motion stopping shaft @ . Now, tighten
nut @ and screw @ .
If there is no clearance between the
driving cam and the stop-motion
stopping shaft, the two components
will come contact with each other.
As a result, abnormal noise will sound.
- 27 —
Standard adjustment
(21) Adjusting the stop-motion presser adjustment screw
Adjust the spring pressure of stop-motion presser adjusting spring @ using stop-motion presser
adjustment screw @ . Maximize the spring pressure as long as malfunction of the cloth cutting
knife does not occur.
у
15
(c=
/
L (С (©
(22) Adjusting the clutch actuating arm
Adjust the clearance between clutch actuating arm € and clutch roller € attached on clutch
lever @ so that they lightly come in contact with each other.
— 28 —
How to adjust
Results of improper adjustment
Adjust the position of stop-motion presser pin o using stop-motion
presser pin adjustment screw @ .
When the machine is in the stop-motion position where stop-motion
bracket @ rests in the cam groove in driving cam O, adjust the
position of stop-motion presser pin adjustment screw O so that
stop-motion presser pin @ has a 0.1 to 0.2 mm vertical play.
Once the adjustment screw has been properly positioned, firmly
tighten nut @ . Be sure to confirm that stop-motion presser
adjusting rod @ come in close contact with the section marked
with an asterisk ( * ).
When the spring pressure has been adjusted to an appropriate value,
fix stop-motion presser adjustment screw @ with screw @ .
Fully tighten screw @ first, then loosen it by a half revolution.
Now, firmly tighten nut @ .
(Caution) Never tighten screw @ on the crest of thread of stop-
-motion presser adjustment screw @ . This may make
the adjustment of the spring pressure impossible.
1. If the spring pressure is too high, the
sewing machine will stop during
sewing.
2. If screw @ is kept fully tightened,
stop-motion pressure adjusting rod
-@ will be pushed against the screw.
As a result, the rod may fail to move
smoothly.
< Phenomenon only occurred in th
MBH-180 >
If the knife fails to go up after the
machine finishes buttonholing and
the knife drops to cut the material,
suppose that the spring pressure is
too low. In the case of using a
heavy-weight material which the
knife may not cut sharp, the knife
cannot go up even if the knife drops
on the material, increase the spring
pressure.
Adjust the position of the clutch actuating arm with screw @ .
If the clearance between the clutch
actuating arm and the clutch roller
is too large, the machine may fail to
start running even if depressing the
foot pedal.
If the two components come in
excessive contact with each other,
abnormal noise may sound when
depressing the foot pedal.
— 29 —
Standard adjustment
(23) Adjusting the thread trimming cam and the thread trimming link
[ Fig. A ] © @ © © ©
Figures - © through © are the
part drawings of Fig. A. Fig. 60
©
а
2 . 5mm ©
Fig. 64
D Thread trimming link
A
5 Link tripping metal
© fitting
— 30 —
How to adjust
Results of improper adjustment
Gradually turning the machine from the state immediately before
the stop-motion (the state where stop-motion bracket rests on
driving cam @ as illustrated in Fig. 61), adjust thread trimming
shaft stopper @ so that thread trimming link @ fitsin thread
trimming cam @ (see Fig. 63) at the same time when positioning
lever @ of the driving shaft enters the first cut groove of needle . -
bar frame driving cam @ (see Fig. 62). At this time, a clearance
of 2.5 mm should be provided between thread trimming shaft
stopper @ and stop-motion suspension € to prevent the two
components from coming in contact with each other.
(see Fig. 64.)
Then, bring thread spreader guide arm @ to the center of the
installing hole of thread spreader { , and adjust so that a clearance |
of approximately 1 to 1.6 mm is provided between the top end of
thread spreader @ and the side face of throat plate @ . Now,
tighten screw @ in thread spreader guide arm. After the adjust-
ment, bring the machine in the stop-motion state.
Then, loosen screw !” to release thread trimming shaft thrust
O , press sto-motion bracket until it comes in contact with
the main body of the sewing machine to make the machine ready
to start. |
Now, lightly press thread trimming shaft thrust @ against the
slant cut plane on stop-motion tripping plate @ , and securely
tighten screw @ .
ее
If the timing of thread trimming and the
clearance between the thread trimming
shaft stopper and the stop-motion
suspension are not properly adjusted,
the thread trimming mechanism may
fail to cut the thread or the length of
thread remaining after thread trimming
may not be uniform.
—31 —
Standard adjustment
(24) Adjusting the re-starting arm (only for the MBH-180)
@
0.5mm
Fig. 67
(25) Adjusting the emergency stop mechanism
1
/ 5 i 0.51. 0mm
—32—
How to adjust
Results of improper adjustment
When the sewing machine is in operation, attach starting arm O
so that the flat section of the arm inclines by approximately 20°.
Then tilt the sewing machine away from you while fully depressing
the foot pedal. Tilting the sewing machine will lower the foot pedal.
So, return the foot pedal to its predetermined position. (Placing a
piece of support block will ensure the position of the foot pedal.)
Keeping the foot pedal at that position, fix re-startingarm @ so
that a clearance of approximately 0.5 mm is provided between
re-starting arm pin @ and re-startingarm @ as illustrated in
Fig. 67.
[f the clearance between the re-starting
arm pin and the re-starting arm is 0 or
less, stop-motion failure may result.
If the clearance is larger than 0.5 mm,
the clutch actuating arm may fail to
properly return to its home position
when restarting the sewing machine,
which means that the sewing machine
will fail to start.
Rotating angle in the direction of arrow €) is determined by the
position of driving cam brake O. Adjust the position of driving
cam brake @ so that the top end of clutch actuating arm @ is
0.5 to 1.0 mm away from clutch roller € when pulling L metal
fitting @ in the direction of arrow , and fix the driving cam
brake, with screw Q , at the position where it comes in contact ..
with the driving cam. At this time, confirm that slide shaft arm
© will not return to its home position without forcibly keeping
it at the adjusted position.
* The MBH-180S/-180L is not equipped with an emergency stop
mechanism.
If the clearance between the top end
of clutch actuating arm and the clutch
roller is O or less, the clutch actuating
arm may break. In this case, a clear-
ance may be provided between the
friction clutch and the driving pulley.
As a result, the machine cannot run
at high speed. Furthermore, larger
clutch noise may sound.
If the clearance is 1.0 mm or larger,
the clutch cannot be disengaged.
As a result, the driving pulley may
become hot.
— 33 —
< Advice in point >
ACF-182, MBH-180S
< Phenomenon >
The sewing machine enters stop-motion during sewing. (Malfunction)
< Cause and corrective measures >
Cause
1. Ratchet spring comes off.
Tilt the machine head, and check whether
the ratchet spring has been out of the
predetermined position or whether the
spring has broken.
pring bro Ratchet spring
2. Ratchet spring loses its
elasticity.
Tilt the machine head, and check whether the ratchet spring has lost its
elasticity by pulling the spring with your fingers.
3. The link presser spring pressure
is insufficient.
Tighten the nut in the link presser spring. The standard position of the nut
is obtained when two or three threads appear from the end face of the nut.
The nut can be tightened to an extent where as many as five or six threads
appear from the end face of the nut.
Link presser spring
Standard number of thread = en
2 to 3 threads 2 NN i о
ann) | ого
5 (DA
4. The change-over lever has been
installed at an improper posi—
tion.
Loosen the four screws illustrated in the sketch below, and change the
installing position of the change-over lever. The installing position cannot be
numerically specified. However, the change-over lever is correctly positioned
as long as the machine does not malfunction when making the machine run
idle by 30 rotations after tightening the screws at appropriate positions.
Four screws
5. The timing to start the first
bartacking is too early.
(The positioning screw excessi-
vely protrudes.)
Adjust the positioning screw illustrated on the left-hand side of the sketch
below. The standard position of the positioning screw is obtained when the
top end of the screw protrudes from the end face of the positioning plate
approximately 3 to 3.5 mm.
Do not set the above-stated protruding amount to 2 mm or less.
3—3.5mm
] +
it
i
!
:
Positioning
screw
Nut
— 34 —
3. TROUBLES AND CORRECTIVE MEASURES
Trouble
Cause (1)
Cause (2) | Inspecting sequence and adjusting procedure
The work clamp foot fails
to go up.
No clearance is provided between the lifter
lever and the work clamp foot mounting base.
Adjust so that a clearance of 0.5 mm is provided between the work clamp
No clearance is provided between the lifter
stopper suspension and the lifter adjusting
block.
foot mounting base and the lifter lever with the work clamp foot lowered.
(See pages 24 and 25.)
No clearance is provided between the presser
tripping bracket and the lifter adjusting
block.
Adjust so that a clearance of 0.5 mm is provided between the lifter stopper
suspension and the lifter adjusting block when the stop-motion bracket is in
its highest position. (See pages 24 and 25.)
Lifter stopper suspension or the adjusting
block has worn out,
The work clamp foot fails
to fully go up.
The clearance between the lifter lever and
the work clamp foot mounting base is too
large.
Adjust so that a clearance of 0.5 mm is provided between the presser
tripping bracket and the lifter adjusting block. (See pages 24 and 25)
-
The screw has loosened. |-— Replace the worn-out components,
If the screw has loosened, re-tighten the screw.
The clearance between the lifter stopper
suspension and the lifter adjusting block is
too large,
— See pages 24 and 25.
The pressure of the stop-motion presser
adjusting spring is insufficient.
— See pages 24 and 25.
Adjust the pressure of the spring using the stop-motion presser adjusting
The knife fails to cut the
cloth, (This trouble occurs
only in the MBH-180.)
screw, (See pages 28 and 29.)
—| The knife does not cut sharp. |
—| The knife dropping position is improper. |
— Replace the knife.
—| Stop-motion failure
Ш,
The knife groove on the throat plate is
defective,
Adjust so that the cloth cutting knife drops just the center of the knife
groove on the throat plate. (See pages 22 and 23.)
Refer to the description of the “stop-motion failure” in “Troubles and
corrective measures”,
— Replace the throat plate. |
Trouble
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure
Stitch skipping occurs at
the parallel scction of a
buttonholc,
The clearance between the looper and the
necdle is too large.
The needle-to-looper
timing is defective.
|
| Takc-up thread guide has been improperly
adjusted,
| See pages 2 through 7.
Shape of the needle hole in the throat plate is
defective. (It has scratches, etc.)
Standard position of the takc-up thread guide is as follows :
Slack of the thread is gradually decrcased by the boss of the descending
ncedic bar lifting arm and the slack of the thread is completely eliminated
when the lowest position of the needle bar is reached.
If raising the take-up thread guide above the standard position, tension
applied to the thread will be increased and the loop will be smaller.
On the other hand, if lowering the guide below the standard position,
tension applied to the thread will be decreased and the loop will be larger.
Since the position of the take-up thread guide affects the thread tension
controlled by the thread tension mechanism, find an appropriate position
ofl the take-up thread guide in accordance with the material and thread
to be used.
ón a La Lo =
If stitch skipping has occurred, check first the following items.
. Whether the needle is bent or whether the tip of the needle is blunt.
. Whether the needle is properly installed.
. Whether the machine head is properly threaded.
. Whether the needle entry point with respect to the needle hole in the
throat plate is correct.
. Whether the thread tension controlled by the thread tension controller
is proper, and whether the take-up thread guide is correctly positioned.
. Whether the position of the work clamp foot with respect to the needle
entry point is correct,
The clearance between the work clamp foot is
too large.
Play between the looper driving cam and the
triangular cam connection is excessive.
| Replace the throat plate. |
|
| Adjust so that the clearance is decreased properly,
—| Decrease the play.
Trouble
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure
Stitch skipping occurs at
the bartack section of a
buttonhole.
The last stitch at the sewing
end skips. (These troubles
occur in the MBH-180/
-180S.)
* Check the cause of stitch
skipping at the bartack
section after taking the
corrective measures
against stitch skipping
at the parallel section of
a buttonhole.
Needle sway during bartacking has been
improperly adjusted,
Thread tension at the bartack scetion has been
improperly adjusted.
|
|
See pages 16 and 17.
-
|
— Properly adjust the thread tension,
_
Clearance between the back of the looper No. 1
and the needle is too large.
The change-over lever overlaps the bartacking
ratchet too deeply during bartacking,
The machine fails to start
even by fully depressing the
foot pedal,
The engaging position of the needle bar driving
gear is improper.
Adjust so that a clearance of 0 to 0.5 mm between the needle and the looper
to allow the needle to drop behind the looper without coming in contact
with the looper. (See pages 4 and 5.)
|
1
See pages 20 and 21.
| See pages 8 and 9,
-
| The starting arm is improperly positioned. | = + See pages 24 and 25. |
The stop-motion suspension and sliding thrust — See pages 26 and 27, |
are not properly positioned,
a i. | nn
The screw in the sliding thrust has loosened, | —| Re-tighten the screw.
The clearance between the clutch actuating arm
and the clutch lever roller is too large.
Adjust so that the clutch actuating arm and the clutch lever roller lightly
come in contact with each other, (See pages 28 and 29.)
The stop-motion tripping lever and the stop-
motion suspension have been improperly
adjusted.
When the bartacking base turns counterclockwise until stop-motion tripping
lever comes in contact with the square projection of stop-motion suspen-
sion, adjust the overlapping length of the stop-motion tripping lever and
the stop-motion suspension to 2.5 to 3 mm. (See pages 26 and 27.)
The stop-motion tripping plate is pushed against
the thread trimming shaft thrust,
Press the stop-motion bracket until it comes in contact with the bed, and
lightly press thread trimming shaft thrust against the slant cut plane on
stop-motion tripping plate. (See pages 30 and 31.)
The stop-motion suspension is engaged with
the thread trimming shaft stopper.
Adjust so that a clearance of 2.5 mm is provided between the stop-motion
suspension and the thread trimming shaft stopper. (See pages 30 and 31.)
Touble
Cause (1)
Cause (2) Inspecting sequence and adjusting procedure
A heavy load is required
to depress the starting pedal.
Stop-motion failure
t—
The starting arm and presser tripping bracket
have been improperly adjusted,
Clearance between the clutch actuating arm
and the clutch lever roller have been improperly
adjusted.
| See pages 24 and 25.
| See pages 28 and 29,
The stop-motion presser pin has been improperly
adjusted.
The belt is not sufficiently tensed. |
When the machine is in the stop-motion position where the stop-motion
bracket rests in the cam groove in the driving cam, adjust the position of
the stop-motion presser pin adjustment screw so that stop-motion presser
pin has a 0.1 to (0.2 mm vertical play. (Sec pages 28 and 29.)
— Adjust the belt tension properly.
Clearance between the clutch actuating arm
and the clutch lever roller is too small.
| See pages 28 and 29.
Pressure of the stop-motion presser spring is
too high.
|
Bartacking brake pressure is too high.
Clearance provided, when the machine enters
the stop-motion state, between the stop-motion
bracket and the driving cam has been improperly
adjusted.
The stop-motion presser pin has been improperly
adjusted, |
The cloth cutting knife docs not cut sharp.
(This phenomenon is observed only in the
MBH-180.)
Decrease the pressure of the stop-motion presser spring.
(See pages 28 and 29.)
Adjust the pressure of the bartacking brake during bartacking so that the
bartacking groove cam follows the rotation of the worm,
(See pages 18 and 19.)
i See pages 16 and 17.
| See pages 28 and 29.
| Replace the knife,
CI
al
antl —
- м -
a к
dede e
Tr STINET AEN
AAA
Troubíie
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure
Thread trimmer fails to
cut the thread.
— The thread trimmer fails to cut sharp. pH
| The shape of the thread
spreader is defective,
——| Replace the thread trimming knife and the thread spreader.
—1 The thread trimming cam and thread trimm-
ing link have not been properly adjusted.
| See pages 30 and 31.
— The thread spreader has been improperly
adjusted.
The performance of the thread
spreader is incorrect.
—1 The pressure of the stop-motion presser
adjusting spring is insufficient.
— The last stitch at the sewing end skips. ia
Increase the pressure of the stop-motion spring. (See pages 28 and
29.)
Refer to the description of the “stitch skipping’ in “Troubles and
corrective measures”,
| Trouble
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure
Stitch failure
ZA
NARA
The feed converting shaft has been improperly
adjusted.
[A
The performance of the feed mechanism is
defective.
| See pages 12 and 13.
The length of thread remaining on the needle
is too short at the sewing start.
Adjust the spring pressure of the feed brake properly. (Tighten the nut
by approximately two threads.)
IF the material is not fed at all, replace the feed mechanism,
(Sce pages 10 and 11.)
The positioning screw has been improperly
adjusted,
The spring of the feed brake is insufficient.
The length of thread remaining on the necdle at the sewing start is
determined by the position of the knife arm connecting link mounted
on the knife arm connecting guide. Move the knife arm connecting link
to the right to lengthen the thread remaining on the needle, or to the
left to shorten it.
|
|
See pages 20 and 21.
Installing position of the change-over lever is
improper.
= —-
Increase the spring pressure. (See pages 10 and 11.)
Loosen four screws © , and change the installing position of the
change-over lever properly. The installing position cannot be numeri-
cally specified. However, the change-over lever is correctly positioned
as Jong as the machine does not malfunction when making the machine
run idle by 30 rotations after tightening screws at appropriate
positions.
| Troubie
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure |
— T-link stopper has been improperly adjusted. |
À See pages 14 and 15. |
Link presser spring pressure has been improperly
adjusted.
Needle sway during bartacking has been
improperly adjusted.
Maximize the spring pressure as long as the stitches do not gather
before starting bartacking, (See pages 22 and 23.)
|
|
L |
See pages 16 and 17,
Link presser spring pressure has been improperly
adjusted. If the nut is excessively tightened (the
screw is tightened to an extent that seven threads
or more of the screw appear from the end face
of the nut), stitch pitch may be excessively
shortened immediately before starting bartack-
ing.
| Loose stitches
—| See pages 22 and 23, |
Take-up thread guide has been improperly
adjusted.
— Thread tension controlled by the tension
controller is insufficient.
Raising the take-up thread lever will increase the tension applied to the
thread, or lowering the lever will decrease jt.
|
OL
Increase the thread tension. |
—1 The thread tension release arm has been
improperly adjusted,
The tension disk floats while the machine is performing bartacking to
prevent the thread from being tensed,
Adjust, when the sewing machine is sewing the parallel sections of a
buttonhole, so that a clearance of 0.5 to 0.8 mm is provided between
thread tension reicase pin and thread tension release arm,
(Sec pages 8 and 9) -
| Needle hole in the throat plate has scratches, =
+ Replace the throat plate, |
| Trouble
Cause (1)
Cause (2)
Inspecting sequence and adjusting procedure
| Needle breakage
The performance of the thread spreader is
defective:
T
The looper components have been improperly
adjusted,
| Thread breakage
The thread used has been spliced.
| See pages 30 and 31.
| See pages 2 through 7.
The needle hole in the throat plate has burrs,
| Replace the thread.
Thread tension is too high.
| Deburr the necdle hole in the throat plate.
| |
|
| |
Г
|
—
Cloth cutting knife fails to
drop properly. (Only in the
MBH-180)
The knife dropping position has been
improperly adjusted.
| Decrease the thread tension.
_
Needle sway during bartacking has been
improperly adjusted,
Adjust so that the cloth cutting knife drops just the center of the knife
slit on the throat plate, (See pages 22 and 23.)
] See pages 16 and 17.
(3) Longitudinal type table
1200
= 40
- 154 i 471 8
Ш 82 R2
had
Í i ÓN |
© 50
{AN 1
17 through
hole
R15 A
À }
1° À A
N Np 7 |
и - — o. m
-- —_ ko { m S 7
a FAY AZ y RT
i Nr I
LE " у 559
Г Tr
| 3
te ++ 42 through hole A MD |
ВЫ En
RDA PET
7 17 140 Y | Y 367 _
В ol o
o A Nu, =! 5
1 | o
! tn
Ч ©
of © - 621.9 _
1 {#7 Stand installing
; position со
{Drill a hole from the 8
rear face at the time о N
of set-up) с;
| с !
‘| ; | 222, 137 475.5 |
1 | Switch installing position
TIN CL (Drill a hole from the
| E a 1 / a) ‘ . o
+ +44 Ä ON 7 TY rear face of the time of set-up) ©
К x и 4 \ 7? À =
a Ÿ LA w Tw >i | Ä R30
LL. -— | ot 8 © 115 oo
— _ 4 < ~
\_ 2 Y Y Y ! y Y
| | |
40 800 100 R2 \R2
3.5
a erm.
$26
ф7 | ф26
30°
AS {
A
—
lg dee
5
Y $8.5
$8.5
Section WW Section YY Section ZZ
—45—
(2) Lateral type table
1200
70
Beit over sheet installing position
(Drit: a hole from the rear face
at ths time of set-up)
17 through hole
{a hole to attach
the thread stand)
12 12
/ __
/ si 4
- 198.3 В 236 _
E En . 64 BO 100 _
| © 2
| LE (в) E 5
„
+ e / X A + J
1 Fam
1 TN \ uu 7 i Z
"7 ~ si
Dt A ©
A A =
; Y Y 49 o
1 i © =r <r
1 - = a -
| 42 through hole с TN
a
LO os A Nu LO
| Stand installing о N | / = | |
J position y
Ä
+ He \ (a (в
(Drill a hole from t о #3 am
rear face at the time = 20 through hole = ТИ Xu,
| of set-up) + & Li y Sy Y
| E © ! eh ! h
i NN NA |
| SL y
: A A
он ! — 316 - 36.3 © h
< = :
- E S
+ o —
A | I JN A
\_ C ; © el E 115 _ №
to } + = — m
= Ï Y { ! \ Ÿ y
A
. 353 \ -
Switch installing hole
(Driti a hole from the rear
face at the time of setup)
67 „026
"Mi . 30°
AD
/ - y
À
| Ä co
Ï | | 685
| e TT
À
ФЗО
Section ZZ
Section YY — 44 —
4. Drawing of the table
(1) Rotary tabie
60
A R30
25.1
17 through hole
(a hole to attach
the thread stand)
106
Note: 1.
2. The position for installing the T stand shall be
360 x 170 and for installing the Z stand should be
380 x 170.
The protective sheet on the upper face of the tabie
shouid not be removed.
534
— 43 —
©
E 35.9 M,
NZJ D
À Xu,
Stand instailing position т
(Dritl a hole from the rear face
at the time of set-up) - 110— —> 1
1
т 8 e 63 ——-
$
7
Ss ©
À @
o
A со | \_ OT +
mie
wl ~ OUT
Lo —
min
£
À
2-20
TT ; through о
o hole © © A
o m | à
a e
3 N
Ug) $ <
5 R162 2-27 through hole
Y r Y | \
} ! N À À ol À À
; Drawer stopper 101 30 . 3 5
installing position - Wire support plate с DN © |
(Drill a hole at 50 26 {c) installing position © Ju ln
the time of setup) . < te (Drill a hole from the © с
- rear face at the time Ÿ O
/ of set-up) №
/ à A / Ta Y i
7 7 LON À
Emergency stopper DA a i N_ o “y
instalting position у 75
‘ (Drill a hole from the 3 1493 30. | 2-15 hole,
ón - o t face; 13 dee
ı rear face at the time of 3-15 hole, | — 27 spo p 2
Po == ‘ setup) 27 spot face; 13 deep - 198.3 -
317.3
- > o
A q N — 342.1 N A
robos o = 800 -
< < Ho.
Ÿ
i
a Switch installing position
nn a © {Drill a hole from the rear fac | %
— _ {© at the time of set-up) q 9
= ! y y fr y Y
Á
115 90
Front /
R2.
R2
To order or for further information, please contact :
JUKI CORPORATION
HEAD OFFICE
8-2-1 KOKURYO-CHO,
CHOFU-CITY, TOKYO 182. JAPAN
BUSINESS OFFICE |
В DC TOKYO 160. JAPAN Please do not hesitate to contact our distributors or agents in your area for further information when necessary.
DN * The description covered in this instruction manual is subject to change for improvement of the
PHONE : 03(3205)1188, 1189, 1190 commodity without notice.
FAX: 03(3203)8260. (3205)9131 * This instruction manual is edited and printed in accordance with the product specifications as of
TELEX : 22967, 232-2301 November, 1991.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising