Brother Industries MA4-B972C User manual

INSTRUCTION MANUAL
For
BROTHER MA4-B972C
High Speed Safety Stitch Overlook Machine
BROTHER INDUSTRIES, LTD.
NAGOYA JAPAN

CONTENTS
1. Specification 1
2.
Features 2
Operation 3
A) SewiiiK .Speed 3
H) Motor,
motor pulley and belt 3
C) .Settin^i up 3
D) Oiling, draining and maintenance 4
K) Needle
cooler device .5
F) Machine operating direction 6
(1) Installing needles 6
II) Threading 6
I ) Stitches 7
.1) Thread tension 7
1. Adjustment of thread take-up 7
2. Adjusting double chain stitch needle thread guide 7
3. Adjusting looper thread take-up and thread guide for overlock stitch 8
4. Adjusting looper thread take-up and thread guides for double chain stitch 8
5. Adjusting thread tension screws 8
K) Adjustment on pressure of presser foot; installing and removing feed dogs: and height of feed dogs 8
L) Adjusting stitch width 9
M)
Adjusting stitch length 10
N)
Adjusting differential feed 10
4. Adjustment H
A) Height of needles 11
F)) Relation between needle and under looper 11
C) Installing needle guard 11
I))
Matching needle guard and needle 11
F) Relation of needle with under looper and over looper 12
F) Relation between needle and double chain stitch looper 12
(1) Installing double chain stitch needle guard 13
II) Installing and
maintenance of knives 13
5. Trouble shooting 14
A) Thread breaks 14
H) Skip stitching 14
C) Needle
breaks 14
D)
Imperfect chaining-off 15
10 Improper thread tension 15
F) Foor trimming performance 15
(i)
Irregular stitches 15
II) Kxcessive wrinkles
along stitches 10
I ) Needles produce too large holes 16

1. Specifications
Name
Dimensions
Stitch form
Sewing speed
Stitch length
Stitch width
Height of presser foot
Lubrication
High speed safety stitch overlock sewing machine
355mm X 240mm X 270mm
Dust-proof, oil-proof, totally enclosed type
E13 & D12, K13A & D12, E12A & D12 simultaneous sewing
Overeclging and blind-hemming of garments, knitwears; Joint seaming on sleeves and
other types of sewing in general
6.000 stitches per minute
1.7mm-3,6mm (7-15 stitches per inch)
Needle g.aige; 2, 3. 5mm
Overedge; 3-5mm in- changing the needle plate
5mm
Automatic lubrication by geared pump plus sprash lubrication and lubrication bv oil
Main bearings and rods All important parts are of i)hospher brou/^e alloy also oilless metal and bait bearings
Oil \'iscosily: CS 20.62 at .37.8'<'
Capacity: 8tX)-l.OOOcc.
Needle bar stroke 24nim
Needle DCxl {—11. i;14, ::16) for overlock stitch
DMxl3 (-11, -14, i 16) for double chain stitch
Feed regulator I'ush-button t\ pe. scale on face plate represents stitch length
Differential feed Hy lever moving in vertical directions: gathering and stretching can be obtained even
regulator in sewing operation.
Knives Upper knife: L-shaped carbide tipped
Lower knife; flat shaped steel
Installation Semi-submerged (.Machine head is installed on the bottom board on which cushion can
support machine head. Only oil reservoir is located below the table top.
Feed regulator
Differential feed
regulator
Knives
Installation
Of this machine, there are the following sub-classc^s available.
- 1 -

SUB-CLASS LIST AND EXPLANATION ON THE MEDALLION
BROTHER INDUSTRIES IT
MADE IN JAPAN
Overedge biglu
Needle gauge
Sewing width
Sub-class
\ -2\ \
-3C — 5C
Needle gauge
2mm \
3mm
5mm
Overedge bight
3mm \N.
5min
5mm
Sewing width
5mm \N.
8mm
10mm
No. of needles
2 \ \ 2 2
No. of threads
A 5 \5
B 4 \4
Differential feed ratio
1.5-0.7 \ 1.5-0.7
1.5-0.7
Needle cooler
Equipped
Equipped
Equipped
Use For thin work
For medium work
P'or medium heavy work
2. Features
The extensive design of various components and lubrication system and also the addition of the needle cooler
device on this model assure
the normal operation of maximum high speed of 6,000 stitches per minute, without
any troubles.
A) Combined lubrication system of forced lubrication by geared pump, sprash lubrication and oil wick lubrication.
B) Unique design of needle bar mechanism has lessened its weight as well as ensures forced lubrication to its
every working part.
C) Exclusively designed over looper mechanism has made the use of light alloy possible and also ensures smooth
lubrication to the end.
D) Holders are made of duralmin to decrease weight. Main rods and bushings are made of phospher bronze alloy.
E)
Major moving parts are perfectly lubricated inside the totally enclosed main body, so they will never be
exposed to outside dusts.
*The upper knife is L-shaped to make the threading and replacement of the needle easy. Besides the carbide
tip promises long durability of the knife.
*Stitch can be easily regulated by push-button, with the scale on the face plate, thus it is unnecessary to change
the eccentrics when you would like to change the stitch length.
*Differential feed can be easily adjusted by the lever for gathering or stretching without soiling your hands.
This also applies for the instantaneous differential adjustment obtainable.
*Durable chain stitch looper's movement in forward-backward direction can be adjusted to obtain the proper
amount of clearance between the looper and needle according to the size of needle.
* Thread tension of the double chain stitch looper can be easily adjusted without opening the cover.
* Ample space on the cloth plate allows easy sewing operation and if you want, double chain stitch with edge
cutting work can be obtained without using the overedging mechanism.
*Oil level in the oil reservoir is shown on the special oil gauge on the front side of the machine.
*Lubrication can be easily checked through the oil window in the top cover.
*Needle cooler device ensures perfect sewing operation even with synthetic materials and threads at the high
speed of 6,000 stitches per minute.
* Colour combination of TAN-BEIGE is in well harmony with your modern factory, and operator's atigue can
be lessened.
* As differental radio can be adjusted up to 2.5, this is suitable for sewing of cloth which is ease to spread
such as knitted fabric.

3. Operation
A. Sewing speed
Maximum speed of this machine is 6,000 stitches per minute. For the first 100 actual working hours, however,
the new machine should be operated at about 5,000 s.p.m. so that all the working parts are well run-in. After
this running-in period, you may operate the machine at maximum speed of 6,000 stitches per minute. This is
desirable for machine's long life.
B. Motor, motor pulley and belt.
1) Use a clutch motor, 1/2 Hp, 2 pole, single or three phase. Our motor available is Models
MD-344 (single phase) and MD-354 (three phase)
2) Use M-type V-belt.
3) Machine speed (s.p.m.), diameter of motor pulley and length of motor belt is related to the following table.
Outside diameter of pulley and length of V-belt
Stitches per minute
50 Hz 60
Hz
Pulley
V-belt
Pulley
V-belt
5,200
115mm
39inch
95mm
38inch
5,500
120 " 39 "
100 "
38 »
6,000
130 » 39 " 110 » 38 "
C. Setting up
This machine is normally set up as semi-submerged type.
Necessary parts and accessories for setting up this machine are contained together with the machine head.
If you have purchased this machine as head only, make the table top as per attached table sheet, also refer
to Fig. 1, which shows the parts necessary for setting up this machine and also the measurement to mount the
bottom board to the table top as semi-submerged type.
With our Brother clutch motor. Models MD-344 and MD-354, there is no anxiety to set the machine to the
bottom board, however, if you would use with other brand clutch motor, please make sure to have proper holes
on the bottom board. 18.4 Centre of V belt
! Screw for cushion base
7^
Bolt hole for bottom board
Collar for bottom
board
Bottom board
Figures are in milimeter (Fig. 1
3 -
Centre of machine
pulley
Cushion base

D. Oiling, draining and maintenance.
Oil is drawn out of the machine prior lo its shipment.
Before operating? the machine, therefore, remt)ve the oil filter cap (shown
in Fig. 2) and pour oil into tlie machine using the funnel.
Oil level should be up lo the upper line of the oil gauge shown in Fig. 3.
1 he oil reservoir consists of two lacks partitioned by a filter, so it takes
sometime before the oil levels of both tanks match. Check if oil is up
to the required level a little after the oil is poured. Add oil if oil level
is below the upper line of the oil gauge.
Be sure to check the oil gauge for oil level before operating the ma-
-Oil
(Fig. 4}
When operating the machine for the first lime after unpacking it or
after it has been out of oil for a long period of time, add o or 6 drops
of oil into the oiling points shown in Fig. 4. and 5. ^'ou do not have to
add oil into them if the machine is operated daily.
At
the end of 100 hours actual operation, running-in period, change the
oil. Thereafter, change it once in about three months use.
The quantity of oil required is about 80()-1.000cc. Remove the screw
shown in Fig. (5. for draining oil.
\
The machine enq^loys a geared pump for the forced lubiication to its
major moving parts. It is recommended that the t)il reservoir be dis
mounted about twice a year for cleaning of its inner surfaces, pump,
wire gauze, etc. This is desirable for long life of the machine.
(Fig. 2)
BR01
(Fig. 5)
(Fig.
6)

E. Needle cooler device
With machine model C", it is equipped with the needle cooler device.
In order to get the good sewing result on the synthetic materials and resin treated materials such as polyester,
jersey, and tricot, etc., or with the synthetic threads, such as Nylon and Dacron, it will he advantageous to use
the needle cooler device.
1. Operating procedure
1) Pour the silicone oil into the lank approxiniEitclv 4/5 in capacil\' ,, . a
^ f I T b
(oOcc in
capacity) then open the cock shown in Fig. 7. w v
2) If this machine is brand new or after it has been out of use for long —m —ilT .jf
time, it takes about 10-15 minutes to saturate the silicone oil into the
felt on the needle guard, then apply several drips of silicone oil {in
the felt so as to thoroughly saturate before sewing operation. B
3) The cock must be closed when the machine do not reciuire the silicone
oil, namely on the slow speed operation or cotton thread, cotton ma- , '
terials applied and also when you do not use the machine. BROTHER |
2. Sewing capability with needle cooler (Fig. 7)
When \'ou would sew the synthetic materials, jerse\'. tricot, etc., it can be ensured to sew upto 6 plies of such
materials at the high speed of 6,000 stitches per minute.
3. Silicone oil to be used
Siljcone oil \'iscosity; .oOOcs
50cc silicone oil could be operated ajjpro.ximately half a month of sewing operation although it depends on the
sewing work.
4. Proper installation on the machine
Overlook
stitch
needle \
guard
Aligning
Overlook stitch
needle guard
Double chain
stitch looper /
Double chain
stitch needle guard.
Vinyl tube
Please be careful not to contact
Double chain
stitch needle
guard
' {Fig. 8) (Fig. 9)
1) The top of the felt must be aligned with the top of the groove of over looper needle guard.(Fig. 8)
In this case, please be careful to set up so that the double chain stitch looper may not contact to the tube.
2) Position of tank
The position of the tank should be set up at the position that the Vent hole is higher than the oil level as shown
in Fig. 7.
3) Removal of the top cover
(Fig. 10)
When you pull the tube Point A to the left as per Fig. 10, the tank and fell portions will be separated, thus
the tank can be detachable together with top cover.
- 5 -

F. Machine operating direction
The proper opcratiag direction of this machine is clockwise as viewed from the pulley side.
G.
Installing needles
Turn Ihc pulley until the needle bar is raised ^
to its highest position, lower the lifter level , '/
®shown in Fig. 11, pressing by the thumb \
finger and move the presser foot arm ffi' to . W U=J
the direction as indicated with arrow mark. i, \ f-Plll D®K—
Now, loosen the needle set screws and holding f^J^\ ® (W^L—
the needles with their grooved side facing | \ ^
toward you, then insert them into the needle (\ W >'|
clamp holes all the way up checking the holes »,
in the needle clamp whether these needles are ^ •- '• I
all the way up. After this check, tighten the l-V,''V. '•
Hole
Needle set screw
(Fig. 12)
H. Threading
Pass the threads through the eyes of the cotton stand then please do in the following order; 1. Under looper
2. over looper 3. double chain stitch looper 4. overlook stitch needle 5. double chain stitch needle.
Before passing these threads, open the front cover, cloth plate and thread take-up cover, turn the pulley until
the needles are at the highest position, and move the presser foot arm outward. Pass the threads as shown
in Fig. 13.
(DUnder looper thread
@ Over looper thread
@Overlock stitch needle
(D Double chain stitch needle ^
thread
(Fig, 13A)
For five threads
(Fig. 138}
For four threads
When you thread to the eyes of thread guides, loopers, and needles, please use with the tweezer in the ac
cessory box.
(Note)
Draw out the thread approximate 5cm from the tip of looper.
Care should be taken for threading of four threads and five threads because of difference between both cases
as shown in Figure ISA and 13B.

I. Stitches
(Fig- 14)
For five threads specification,
parallel stitching of 1)12 and F13
combination is arranged upon
adjusted (Figure 14). but rearrange
ment parallel stitching of D12 and
K13A combinalion(Figure I5)could
also be accomplished upon adjust
ment with turning the adjusting
(Fig. 15)
In case of the F13/D12 combination,
the over looper needle thread and
double chain stitch needle thread
have the strongest tension, followed
by the under looper thread tension
and then the over looper and double
chain stitch looper threads tension,
For four threads specification,
parallel stitching of D12 and F12A
combination (Figure 16) is arranged
upon appropriate adjustment.
J. Thread tension
Thread tension may change depending on the type of thread and material
positions of the thread take-up and thread guides. If it should change co
following manner
1. Adjustment of thread take-up
Needle thread will be ease to be tightened if the thread take-up is
lowered and be ease to be loosened if the thread take-up is raised up
on the contrary. J
The thread take-up in the middle position is the standard thread tension. I
(Fig. 17) f
Figure A will be applied to a thread take-ui) for five threads specifi- i
cation, and Figure B will be applied to a thread take-up for four threads i
specification.
2. Adjusting double chain stitch needle thread guide: K
To tighten the needle thread, raise the double chain stitch needle thread ft
guide. To loosen it. lower the guide The guide in the middle position I
is the standard thread lension.(Fig 17) I
(Fig. 16)
In case of the FI2A / D12 or
E13A/D12 combination, the double
chain stitch threads tension remain
the same, however, the overlook
stitch thread's tension must be
changed. In this case, the under
looper thread has the strongest ten
sion. followed by the
over loojDcr
thread tension and then overlock
needle thread tension.
sewn, stich width, stitch length the
isiderably. make adjustment in the
Thread take-up
(Fig 17)
Fig
.-X

3. Adjusting looper thread take-up and thread guide for overlock stitch :
oper
read takf-up ^
♦ ..
Looper
'|hread tak^up ^
a9/2-2C-
(Fig. 18) (Fig. 19)
As shown in Fig. 18 at the highest position ol' the needle, it is the standard position of the looper thread take-
up and thread guide, for the three threads overlock stitch.
In this case, the position of under looper thread guide shows in B is for cotton ihi'ead and A for synthetic thread.
As shown in hig. 19, at the highest jjosition of the needle, it is the standard position of the looper thread take-
up and thread guide, for the two threads overlock stitch.
4. Adjusting looper thread take-up and thread guides for double chain stitch :
As shown in Fig. 20. at the highest iiosition of the needle, it is the
standard position of the double chain stitch looper thread take-up and | Machine Body
Thread Handler
thi'ead guides.
Double chain
thread'°aK-up lowest point of the
thread taKe up guide's hole is in
level with top of looper
thread take-up
5. Adjusting thread tension screws:
After completion of the above-mentioned adjustment of the thread guides and thread take-up. turn the thread
tension screws for fine adjustment.
Incorporate an appropriate adjustment for the above "stitches" (Page 7).
He careful not to turn the screw in or out exce.ssively. because it may tighten the threads more than neces
sary or cause the thread take-up to feed (he threads too excessively
K. Adjustment on the pressure of presser foot :Installing or removing feed dogs • and Height
of feed dogs: ^
'iM t I r , , . Presser foot io I
1he pressure ol tiie presser fool can he adjusted h\' means of the adjusting screw m
presser foot adjusting screw shown in Fig 21 \
Tig. 22)
(Fig 21)
Follow llie instructions given below to install or remove the feed dogs:
(Fig. 22)
To install the differential feed dog "S'. tighten the screw ®.
'Ik) install the mam feed dog C'. tighten the screw 0.