JUKI MB-1373 User manual

i
ENGLISH
INSTRUCTION MANUAL

i
CONTENTS
1. SPECIFICATIONS ........................................................................................................... 1
2. PREPARATION OF THE SEWING MACHINE ................................................................ 1
2-1. Installation ..........................................................................................................................................1
2-2. Lubrication.......................................................................................................................................... 2
2-3. Attaching the needle..........................................................................................................................2
2-4. Attaching the needle bar cover.........................................................................................................3
2-5. Attaching the button tray assembly .................................................................................................3
2-6. Threading the machine...................................................................................................................... 3
3. ADJUSTMENT OF THE SAWING MACHINE ................................................................. 4
3-1. Thread tension adjustment........................................................................................................................ 4
3-2. Adjustment of the thread pull-off lever .................................................................................................... 4
3-3. Adjusting the tension lever ...............................................................................................................4
3-4. Adjusting the nipper ..........................................................................................................................5
3-5. Adjusting the thread tension guide on the face plate.....................................................................5
3-6. Needle-to-looper relation .................................................................................................................................... 5
3-7. Position of the needle guide ............................................................................................................. 6
3-8. Height of the button clamp................................................................................................................ 6
3-9. Work pressing force ..........................................................................................................................6
3-10.
Adjustment of the button clamp stop lever.....................................................................................6
3-11. Timing of thread tension release ....................................................................................................7
3-12. Setting for 2- or 4-hole buttons....................................................................................................... 7
3-13. Setting a number of stitches........................................................................................................... 8
3-14. Adjusting the position of the stop-motion.....................................................................................8
3-15. Automatic thread trimmer ...............................................................................................................9
(1) Adjusting the position of the moving knife......................................................................................9
3-16. Clearance between the button clamp lifting lever and the adjusting screw .............................. 9
3-17. How to set the L-shaped lifting rod ................................................................................................9
3-18. Knot-tying mechanisms ................................................................................................................10
(1) Adjusting the knot-tying connecting plate..................................................................................... 10
(2) Adjusting the knot-tying arm stopper............................................................................................ 10
(3) Adjusting the knot-tying notch ......................................................................................................10
(4) Changeover of with/without knot-tying ......................................................................................... 11
4. MAINTENANCE, SUBCLASS MODELS AND ATTACHMENTS .................................. 11
4-1. How to connect the metal ttings of the belt ................................................................................ 11
4-2. Subclass models ............................................................................................................................. 11
4-3. Attachments......................................................................................................................................12
(1) Attachments for shank buttons (Pearl buttons) (Z033) ................................................................13
(2) Attachment for the rst process of wrapped-around buttons (Z041)............................................13
(3) Attachment for the second process of wrapped-around buttons (Z035) ...................................... 14
(4) Attachment for snaps (Z037)
........................................................................................................14
(5) Attachment for metal buttons (Z038)............................................................................................ 15
4-4. Motor pulley and belt .......................................................................................................................15
5. TROUBLES AND CORRECTIVE MEASURES ............................................................. 16

– 1 –
1. SPECIFICATIONS
MB-1373 MB-1377
Sewing speed Normal 1,300 sti/min (Max. 1,500 sti/min)
Number of stitches 8, 16 and 32 stitches
Feed amount Lateral feed 2.5 to 6.5mm
Longitudinal feed 0, 2.5 to 6.5mm
Lateral feed 2.5 to 6.5mm
Longitudinal feed 0, 2.5 to 4.5mm
Button size 10 to 28 mm
Needle used TQx1 #16 (#14 to #20) TQx7 #16 (#14 to #20)
Lubricating oil JUKI New Defrix Oil No. 1
Noise -Equivalent continuous emission sound pressure level (LpA) at the workstation :
A-weighted value of 84 dB; (Includes KpA = 2.5 dB); according to ISO 10821-
C.6.3 -ISO 11204 GR2 at 1,300 sti/min.
2-1. Installation
2. PREPARATION OF THE SEWING MACHINE
Put rubber cushion 1on the table,
place the machine head on the rubber
cushion and x it to the table using
screws 2, plain washers 3and nuts
4. Attach “S” chain hook 6and chain
7to stop motion trip lever 5.
1
2
4
3
6
7
5

– 2 –
2-3. Attaching the needle
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
★Use a standard needle of TQx1 #16.
Loosen setscrew 1and hold needle 2with the long
groove facing toward you. Then fully insert it into the
hole in the needle bar, and tighten setscrew 1.
1
2
1
2[Caution at the time of lubricating]
1. Take care not to allow speed slowing friction
wheel 1and friction plate 2to be clogged with
oil to prevent them from the deterioration of
retardation performance. In addition, when the
components are clogged with oil, wipe the oil
from them.
2. Take care not to allow the machine belt to
be clogged with oil to prevent it from the
deterioration.
1
9
2
3
5
67
!1
!0 8
!2
!4
!5
!6
!3
2-2. Lubrication
1) Open the side cover, and apply JUKI New Defrix Oil No. 1 to the
portions shown by the red marks 1to !2 (7: MB-1377 only).
(Apply approximately 1 cc of oil to the respective lubricating
places one to two times a week.)
2) Loosen connecting screw !3, tilt the machine head backward
and apply grease (JUKI designated grease) to crossed helical
gear !5 and worm gear !6.
3) Check, approximately once a week, that oil amount is sufcient
to reach the top of the oil felt placed inside the bed mounting
base. If the amount of oil is insufcient, add an adequate amount
of oil. At this time, also apply oil to crank rod !4.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
4

– 3 –
2-5. Attaching the button tray assembly
2-6. Threading the machine
Thread the machine head in the order of 1to @1 as shown in the illustration given above. Then, pass the
thread through the needle eye from the front for approximately 60 to 70 mm as you depress nipper releasing
knurled thumb nut A.
* Standard needle is TQ X 1 #16.
1) Loosen screw 2and remove thread guide 3.
2) Place needle bar guard 1under thread guide
3and attach thread guide 3so that lever 4
comes to the center of it at the start of the ma-
chine.
3) Fix the cover with screw 2.
2-4. Attaching the needle bar cover
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
Insert the posts of button tray 1in hole on the right
of the machine sub-base and tighten each setscrew
2. If it is difcult for the operator to pick up the but-
tons on the right side, change it to hole 3on the left
side.
1
2
1
2
43
3
1
2
5
6
7
8
9
!3
!1
!2
!6
!4
!5
!9
!7
!8
A
@0
@1
!0
4 3

– 4 –
3-2. Adjustment of the thread pull-off lever
To adjust the thread pull-off lever 1, insert a screwdriver through an opening in the machine arm side cover
(left), loosen screw 2and adjust the position of nipper bar block (rear) 3to the left or the right. If the end of
thread is drawn from arrow hole A in the button after sewing, change the position of nipper bar block (rear) 3
to the left. Move the lever to the right when the thread end comes out from arrow hole B.
3-3. Adjusting the tension lever
1) When the machine is in the stop-motion state,
loosen screw 1.
2) Tighten setscrew 1so that there is a clearance
of 8 to 10 mm as a standard between the end of
thread tension guide 3and end of lever 4.
After the adjustment, make sure that the
thread path is within the slot as illustrated in
Fig. Awhen the machine starts.
If the thread paths do not coincide with each
other, loosen screw 2in the tension thread
guide and adjust it properly.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
A
B
1
2
3
At the time of X
stitching
8 to 10 mm
1
2
4
3
A
3-1. Thread tension adjustment
3. ADJUSTMENT OF THE SAWING MACHINE
1
2Tension post No. 1 1is used to adjust the thread
tension to sew on the button and a relatively low
tension will be enough. Tension post No. 2 2is
used to adjust the thread tension applied to the root
of the button sewing stitches. This tension must be
determined according to the type of thread, fabric
and thickness of the button and must be higher than
that of tension post No. 1 1. Turn the tension nuts
clockwise to increase or counterclockwise to reduce
the thread tension.

– 5 –
3-4. Adjusting the nipper
0.4 to 0.6 mm
1
2
1) Provide a 0.4 to 0.6 mm clearance
between nipper block 2and nipper
1to prevent the nipper 1 from hold-
ing the thread while the machine is in
operation.
2) Loosen screw 3and move nipper bar
block 4 to the right or the left.
3-5. Adjusting the thread tension guide on the face plate
★Adjust the needle-to-looper relation as follows :
1) Depress the pedal fully forward, turn the needle driving pulley in the normal sewing direction by hand to
bring down the needle bar to the lowest position of its stroke and loosen screw 1.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
3-6. Needle-to-looper relation
If the formation of seams at the start of sewing is
failed and the seams are formed on the way even
when the thread pull-off lever is adjusted, turn thumb
nut 1(double nut) to decrease the thread tension.
1
2
2
3
AB
C
5
4
6
2
TQx1
TQx7
4
3
(Adjusting the needle bar height)
2) Adjust the height of the needle bar using the top
two lines engraved on the needle bar 2 for the
TQx1 needle and using the bottom two lines for
the TQx7 needle. Align the upper line Awith the
bottom end face of needle bar bushing (lower)
3and tighten screw 1. At this time, tighten the
screw so that groove Cof the needle faces the
front.
(Looper position)
3) Loosen screws 4and turn by hand the needle driv-
ing pulley until lower line Bof two lines aligns with
the bottom end face of needle bar bushing (lower) 3.
4) By keeping the machine in this state, align looper blade
5with the center of the needle and tighten screws 4.
5) Loosen screws 6and provide a 0.01 to 0.1 mm
clearance between the looper and the needle.
Tighten screws 6.
1

– 6 –
3-10. Adjustment of the button clamp stop lever
When clamp screw 1is loosened in the state of
stop-motion, button clamp jaw levers 3opens/clos-
es with button clamp stop lever 2. Set a button to
the correct position and x button clamp stop lever
2at the position where taking in and out of the but-
ton is easily performed with clamp screw 1.
3-7. Position of the needle guide
Loosen screw 2and provide a 0.05 to 0.1 mm clear-
ance between the needle guide 1and the needle
by moving the needle guide 1to the left or the right
when the needle is in the lowest position.
3-8. Height of the button clamp
1) The standard clearance Abetween the rear side
of the bottom face of button clamp jaw lever 1
and the top surface of feed plate 2is 8 mm at
the position where the machine has stopped after
sewing.
2) To adjust the height of the button clamp unit,
loosen screw 3in the button clamp lifting hook
and move button clamp lifting hook 4up or
down.
3-9. Work pressing force
The standard work pressing force is by providing a
28.5 to 29.5 mm between the top end of nut 1and
the bottom end of pressure adjusting bar 2.
Turn nut 1to adjust it.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
12
3
4
3
2
1
A
28.5 to
29.5 mm
2
1
1
2
0.05 to 0.1 mm

– 7 –
3-11. Timing of thread tension release
Turn the needle driving pulley as you draw the thread in the direc-
tion of arrow mark A and you will nd a point at which the tension
discs on the tension post No. 2 release the thread. At this moment,
the standard distance from the top end of the needle bar bushing
(upper) to the top end of the needle bar is 44 to 47 mm (in case of
the needle of TQ X 7, 54 to 57 mm).
Perform the following adjustments especially when the undermen-
tioned troubles occur frequently.
Loosen nut 1, insert the blade of a screwdriver to the top slot of
the tension post No. 2 and turn it in the direction of arrow mark B
to lower the height of the thread oating bar and in the opposite
direction to raise the height.
3-12. Setting for 2- or 4-hole buttons
Perform the adjustment after
confirming that the sewing
machine is located at the
position of the stop-motion (refer
to "3-14. Adjusting the position
of the stop-motion", p.8).
Measure the distance between two
holes in a button and set equally cross-
wise and lengthwise feed regulators for
4-hole buttons.
[In case of MB-1373]
★Lengthwise feed
Push down lengthwise feed
adjusting lever 1and set it to
“0” for 2-hole buttons or a cor-
responding amount for 4-hole
buttons.
★Crosswise feed
Loosen nut 2and set sec-
tion Aof pointer 3to a
corresponding amount. Then
tighten nut 2.
Phenomenon Height of thread oating bar
1.When the stitch made on the wrong side of the
workpiece is too loose ;
Make the needle bar slightly higher.
2.When the thread is broken at the time of stop-motion ; Make the needle bar slightly lower.
3.When the thread is broken frequently ; Make the needle bar slightly lower.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
1
2
3
B C A
1
A
MB-1377
A
[In case of MB-1377]
★Lengthwise feed
Push down lengthwise feed adjusting lever 1and set it to "0" for -2-hole
buttons or a corresponding amount for 4-hole buttons by the respective
procedures below according to the sewing methods.
X stitch : Set the lengthwise feed adjusting lever to the position corre-
sponding to the amount for the button within the range of A.
U-sharp stitch : Set the lengthwise feed adjusting lever to the position cor-
responding to the amount for button within the range of B.
When setting the lengthwise feed adjusting lever to the position of
C (outside of range of setting the lever), not only the sewing cannot
be performed but also trouble will be caused. Do not set the feed
adjusting lever at the position of C.
★Crosswise feed
Loosen nut 2and set section Aof pointer 3to a corresponding amount.
Then tighten nut 2.
Before operating the machine, ensure that the needle enters the
center of each hole in the button.
B

– 8 –
3-13. Setting a number of stitches
To change the number of stitches, open the left-hand side cover and change the number of stitches using
stitch number adjusting screw 1and stitch number adjusting lever 4(optional).
★ How to adjust 8 stitches
In the state of 16 stitches, stitch number adjusting
gear roller 2which is attached to the large gear 5
comes to the lower side, assemble stitch number
adjusting lever 4(supplied as accessories) using
hinge screw 3(supplied as accessories).
When stitch number adjusting screw 1being set for
"8 stitches" has arrived at the left end, loosen stitch
number adjusting screw 1 and x it to the position
as shown in the illustration.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
1
1
2
4
3
5
To make 8 stitches, loosen stitch number adjusting
screw 1 and x it to the position as shown in the
illustration.
★How to adjust 16 stitches
★How to adjust 32 stitches
2
1
3
4
A
B
3-14. Adjusting the position of the stop-motion
Adjust so that claw 1of the stop-motion cam comes
in contact with stop-motion hook 2when the sewing
machine completes the sewing and stops.
When replacing the motor pulley and
changing the sewing speed from 1,300 sti/
min to 1,500 sti/min, and vice versa, be sure
to re-adjust the position of the stop-motion.
[Adjusting procedure]
• When the stop-motion hook comes in
contact with the stop-motion cam and
rebounds, (When there is a clearance
between claw 1and stop-motion hook 2)
loosen two stop-motion position adjusting
screws 3, turn stop-motion adjusting cam 4
in the direction of A, and x stop-motion posi-
tion adjusting screws 3.
• When the stop-motion hook stops before it
comes in contact with the stop-motion cam claw
Loosen two stop-motion position adjusting
screws 3, turn stop-motion adjusting cam 4
in the direction of B, and x stop-motion posi-
tion adjusting screws 3.