Mitsubishi LT2-2230 User manual

A
MITSUBISHI
INDUSTRIAI.
SEWING
MACHINE
Model
LT2-2230
Classes
Double-Needle
Needle feed
Lockstitch, Automatic
Undertrimmer,
Variable Speed
INSTRUCTION MANUAL
From the library of: Superior Sewing Machine & Supply LLC

PRECAUTIONS BEFORE STARTING TO OPERATE
(1) Safety Precautions
1. Keep your hands and fingers away from the area around the needle and the
area around the pulley when turning the power on.
2. Power must be turned off when the machine is not in use, or when the
operator leaves his/her seat.
3. Power must be turned off before tilting the machine head, installing or
removing the "V" belt, adjusting the machine, or replacing its parts.
4. Avoid placing fingers, hair, bars etc., near the pulley, "V" belt, bobbin
winder, or motor when the machine is operating.
5. Do not insert fingers into the thread take-up cover, under/around the
needle, or pulley when the machine is operating.
6. Ifa belt cover, finger guard, and/or eye guard are installed, do not operate
the machine without these safety devices.
(2) Precautions before Starting Operation
1. If the machine's oil pan has an oilsump, never operate the machine before
filling it.
2. If the machineis lubricatedbya drop oiler, neveroperate the machinebefore
lubricating.
3. When a new sewing machine is first turned on, verify the rotational
direction of the pulley with the power on.
.(The pulley should rotate counterclockwise when viewed from the pulley.)
4. Verify the voltage and (single or three) phase with those given on the
machine nameplate.
(3) Precautions for Operating Conditions
1. Avoidusing the machine at abnormally hightemperatures(35°C or higher)
or low temperatures (5°C or lower). Otherwise, machinefailure may result.
2. Avoid using the machine in dusty conditions.
From the library of: Superior Sewing Machine & Supply LLC

-CONTENTS-
PREPARATION FOR OPERATION
m Power cable connection 1
[2 Connection of control box 2
[Tl Adjustment of needlebar stop position 3
CAUTIONS ON USE
mOiling (2) 4
r2l Oiling condition and adjustment on oiling to thread take-up lever 5
m Adjustment of oiling to rotating hook 5
IT] Cautions on operation 5
OPERATION
10
11
12
13
14
15
16
17
Installation of needles 6
Winding of bobbin thread 6
Selection of thread 7
Threading of needle threads 7
Adjustment of stitch length and stitch reversing (touch-back) 8
Setting of bobbin 8
Adjustment of needle thread guide 8
Threadingof bobbin threads 9
Tension adjustment of bobbin threads 9
Balance of thread tension 9
Needle thread tension 9
Adjustment of presser foot pressure 9
Timing between rotating hook motion and needle motion 10, 11
Adjustment of feed dog height 12
Relationship between rotating hook motion and take-up lever motion 13
Relationship between hook motion and opener motion 13
Relationship between needle motion and feed dog motion 14
Installation of movable knife 15
Adjustment of thread trimmer cam 16
Adjustment of thread tension regulator 17
Adjustmentof meshing pressureof movableknife and fixed knife 18
Sharpening of fixed knife 18
Adjustment for change of needle gage 19
Wiper adjustment 20
ADJUSTMENT AND OPERATION OF CONTROL UNIT
m "1-2 POSITION" select switch operations 21,24
m Pedal operation 21,24
mAdjusting the pedaling forces 21,24
m Adjustingthe stitching speed 22,25
fSl Optional functions 23, 26, 27
CAUTION 28
From the library of: Superior Sewing Machine & Supply LLC

PREPARATION FOR OPERATION
• Overall view of
assembled
sewing machine
X-type LIMI-STOP motor
Touch back
switch
Z-type LIMI-STOP motor
Operation box (option)
Balance wheel
(included synchronizer)
V type belt
Power push button
X-type LIMI-STOPmotor
Receptacles for
machine cables
Control box
• Overall view of
assembled
sewing machine
Arm
Operation box
Balance wheel
Face plate
Touch back
switch
Z-type
LIMI-STOP motor
Phase
reversing plug
Control box
rn Powercable connection
1.1 Connectors
^^vtype
13
Receptacles for
machine cables
Rubber cushion
Power push button
The connector (plug) of cable to be connected to the control box should be set to the corresponding
receptacle after checking the direction of connection to be set.
— 1 —
From the library of: Superior Sewing Machine & Supply LLC

1.2 Lamp Leads (standard type)
(1) When a work lamp (6\/, 15 to 20W) is used, remove the insulation
tube from the lamp leads found at the sideface of motor. Then, strip
the leads properly and connect them to the lamp. After the
connections with an insulation tape.
CAUTION
Awork lamp voltage is 6V, but a voltage to ground from lamp leads
is about 10OV.
Be sure to turn off the power switch before the connection.
(2) When a work lamp is not used, insulate the two lamp leads as
shown in figure at right hand.
If the lamp leads are shorted, the motor windings burn out.
CAUTION
Do not connect the work lamp in parallel to any heating apparatus,
e.g. foot warmer. Otherwise the load capacity is exceeded and the
motor windings burn out.
Lamp lead
Insulating tapes
(wind 2 or 3 times)
12) Insulating tape
(wind 2 or 3 times)
/
Lamp lead
Cut the bare wire.
About 10mm
or more
1.3 Power Source Connection
(1) When a three-phase motor is used, connect phase Uto the red lead, phase Vto the white lead, and phase W
to the black lead. Be sure to connect the green lead to the ground terminal.
(2) For
power fuse, consult with near by lecated electrician or our service agency.
(3) The capacity of fuse inside the control box is 8A.
1.4 Rotating Direction
Therotating direction ofmotorcan bereversed byremovingthe rotationreversing plugon the side face ofmotor,
turning it 180° and setting itagain. Fora sigle-phase motor, turn on the switch after the motor has completely
stopped (approximately two minutes required). Also, be sure to insert the plug securely to the full depth.
[n Connection of control box
The control box should be connected as shown to the right. (Z-type LIMISTOP motor)
Round hole in table-
Note: (1) Be sure to turn the power switch
off for safety before connecting
or disconnecting the connectors.
(2) The combination of the machine
heads with the motor control
panels are specified below. Use
special care for the correct
combination when replacing the
machine head or motor control
panel.
Operation box
Machine head model
Control box model
LT2-2230-L
LF-AMDF-*37
LT2-2230-M
LT2-2230-B
LF-AMDF-'30
Speed setting
external VR
Operation box
means using voltage
1; 100V.200V
2: 220-240V,110~120V,110/220V
3: 220/380V,340V,380V,400~440V
Power source
Clutch
Brake
— 2 —
Option
Synchronizer
"1-2 POSITION"
select switch
Sewing
machine
Presser
foot
Option 2
From the library of: Superior Sewing Machine & Supply LLC

The control box should be connected as shown to the right. (X-type LIMI STOP motor)
Note: (1) Besure to turn tne powerswitch
off for safety before connecting
or disconnecting the connectors.
(2) The combination of the machine
heads with the motor control
panels are specified below. Use
special care for the correct
combination when replacing the
machine head or motor control
panel.
Machine head model
Control box model
LT2-2230-L
XC-AM-»*37
LT2-2230-M
LT2-2230-B
XC-AM-**30
Operation
box
Round hole
in table
a-f Alt ttal
•• means usihg voltage
12: 110V--120V
24: 220V ~ 240V
UvlR ENCOCCM iPtlfi
[3] Adjustment of needle bar stop position
1. Adjust of "UP" position
When the pedal is kicked down by heel, the
machine stops at "UP" position. If the marks
deviate larger than 3 mm, adjust as follows.
—1. Disconnect
the plug (12 pins) ofcable from
the machine head.
—2. Runthemachineandstopat"UP"position.
—3. Whileholdingthe pully, insertthe "adjus
ting tool" in the hole ®, then remove the
tool.
2. Adjust of "Down" position
When the pedal is "Neutral" the machine
stops at "DownSB position. If the marks deviate
large than 5 mm, adjust as follows.
—1. Disconnect the plug (12 pins) ofcable from
the machine head.
—2. Run the machine and stop at "Down"
position.
—3.
While holding the pully, insert the "adjusting
tool" in the hole <B), then remove the tool.
3. Confirm thestopoepration, thensettheplug(12
pins) coming from the machine head into the
receptable.
— 3 —
Pully
Timming mark Arm
white mark "Up" position
Black mark
"Down" position
Adjusting
tool
AFTER
BEFORE
From the library of: Superior Sewing Machine & Supply LLC

CAUTIONS ON USE
rn Oiling (1)
Fill the oil reservoir with oil up to "H" mark. Oil
level
should be periodically checked. If oil level is
found below "L" level replenish oil to "H" level.
For oil, use white spindleoil specified by Mitsubishi.
Oiling (2)
When a new sewing machine is used for the first
time, or sewing machine left out of use for
considerably long time is used again, replenish a
suitable amount of oil to the portions indicated
by arrow in the below figures.
Amount of oil ... 5 ~ 6 drops
— 4 —
Oil level
Don't replenish oil here in the
case of "B" type sewing
machine!
From the library of: Superior Sewing Machine & Supply LLC

CAUTIONS ON USE
[Tl Oiling condition and adjustment on oiling Adjustment on oiling to rotating hook
to thread take-up lever
(1)See dripping of oil during operation through
the oil sight window to check oiling
condition in the machine arm.
(2)Please use the oiling adjusting screw with
respect to oiling to thread take-up lever
mechanism.
Increase Decrease
@ Cautions on operation
Oil sight window
Oiling
adjusting
screw
(DWhen the power is turned on or off, keep
foot away from the pedal.
(2) It should be noted that the brake may not
work when the power is interrupted or
power failure occurs during sewing machine
operation.
(3)Since dust in the control box might cause
malfunction or control troubles, be sure to
keep the control box cover close during
operation.
(4) Do not apply a multimeter to the control
circuit for checking, otherwise voltage of
multimeter might damage semiconductor
components in the circuit.
-5 —
Adjusting
Screw
ecrease
Increas
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Note: Before installing the needles, be sure to turn off the power.
pn Installation of needles
Put each needle into needle socket
until it is stopped at the bottom of
needle socket and turn two needles
so that their prime grooves are posi
tioned oppositely each other. Then
tighten set screws.
n
O
Needles are not
fully inserted.
n
Needles are set in
wrong direction.
Position the prime
grooves oppositely
each other.
Winding of bobbin thread Note: When bobbin thread is wound, keep the presser foot lifted.
Adjustment:
• Tension of wound thread
• Conically wound thread
• Length of wound thread
m
Slack winding is recommended for polyester thread and nylon thread.
Move the thread guide toward smaller diameter of wound thread layer,
Loosen the thread length adjusting screw to increase length of thread
and tighten the screw to decrease length of thread.
Thread tension
adjusting nut
Thread guide
Thread winding quantity
adjusting screw
Bobbin should be
filled with cylin-
drically wound
thread up to 80%
of b-^bbin capacity.
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
[3] Selection of thread
It is recommended to use "S" twist thread in
the left needle (viewed from front), and "Z"
twist thread in the right needle.
When discriminate use of needle threads is im
possible, use "Z" twist thread in both the
needles. For bobbin thread, "S" twist thread as
well as "Z" twist thread can be used.
[T] Threading of needle threads
(1) Pass each needle thread through thread
guide @.
Note: When thin slippery thread (polyester
thread or filament thread, for example) is
used, pass the thread through thread guide
(J) as well.
(2) With the take-up lever located at the upper
most position, pass each needle thread in
the order shown in the following figure.
Note: Pressing the upper thread loosening
button shown in the figure below opens the
saucer of the upper thread tension adjuster,
and the upper thread can easily pulled out.
Needle thread tension releasing button
GDdD
(IT)(rJ)\(0) Ck kD (kD (0)(0)
Lead the Lead the
thread thread
leftward, rightward.
^(Seedetailed figure.)
Needle
thread
— 7 —
S twist thread
Z ' twist thread
® (1) ®(D ®
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Adjustment of stitch length and stitch
reversing (touch back)
Note: To make stitch length smaller, depress
the feed reverse lever and set the stitch length
setting dial to a desired position.
Stitch length ^
setting dial
Feed reverse
lever
[6! Setting of bobbin
(1) Pull out 5 cm thread tail from the bobbin.
(2) Hold the bobbin so that the bobbin thread is would
in right direction and put it into the hook.
Ft] Adjusting,of needle thread guide
Please adjust needle thread guide of n'.^edle thread
tensioner according to sewing condition.
Thread
guide
position
Left Middle
Right
Materials
The thicker
than
standard
The thin
ner than
standard
Needle
thread
supply
More Standard Less
• Touch-back button ... Direction of stitching
can be reversed by depressing this button.
Stitching goes on in reversed direction while the
button is held down, and returns to forward
direction when the button is released.
Thread tail
Touch-back
^ button
— 8
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
[si Threading of bobbin threads
(1) Put bobbin thread into the slit (j}, pass under
the lug (2) and extend it below the bed.
Thread
Thread
Opener
(2) While holding the two needle threads by left
hand, rotate the handwheel one turn by right
hand. By pulling up the needle threads, as
shown in the figure, the bobbin threads will be
lifted. Both of bobbin thread and needle thread
should be aligned and led backward.
Tension adjusmtnet of bobbin threads
Tension adjusting
screw
Loosen
Tighten
Balance of thread tension
AO
Balanced tension
BX
po-i-r^
Tight needle or loose
bobbin tension
CX
Loose needle or tight
bobbin tension
ITil Needle threadtension
* Needle thread tension should be adjusted in
reference to bobbin thread tension.
• To adjust needle thread tension, turn each ten
sion adjusting nut.
Needle thread tension can be also adjusted for
special fabric and thread by changing intensity
and stroke of thread take up spring.
Tighten
..
Thread tension
adjusting nut
12 Adjustment of presser foot pressure
Pressure to fabric(s) can be adjusted by turning the
pressure adjusting screw.
Weaken Tighten
-9-
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Timing between rotatina hook motion
and needle motion
(DSet stitch length on the stitch length setting
dial shown table.
(2) When needle is lifted @ shown table, from the
lowest position, the followingpositional relation
ship should be maintained.
—The upper edge of needle eye should be
1.0 ~ 1.6 mm below the hook point.
—The hook point should be located at the
center of needle axis.
—Gap between the hook point and the side
face of needle should be 0.05mm.
(3) Needle/rotating hook position can be ad
justed as follows.
(For easy adjustment, it is recommended
that the presser foot, throat plate and feed
dog assemblies are removed.)
• Position adjustment of hook point
Adjust the hook point so that it comes to the
center of needle axis.
ID Lean the machine head backward and loosen
three set screws of hook shaft gear (small).
(2) Turn the balance wheel and stop when the
needle is lifted (§) mm shown table from the
lowest position.
(3) Rotate the hook by hand to position the
hook point to the center of needle axis.
(4) Move the
hook bracket leftward or right-
ward and position it so that gap between the
hook point and side face of needle is 0.05
mm. For this adjustment, each screws (§) ,(§)
and two of should be loosened.
Note: In the adjustment, do not excessively
loosen set screws©and always maintain mesh
ing of hook shaft gear and lower shaft gear.
(5)Tighten the set screwsinthe followingorder:
(j) While pressing the lower shaft gear (large)
against the side face of hook bracket,
tighten the set screws(£)first.
@ After checking gap between the needle
and the hook, tighten theset screws@^
(D Then tighten thesetscrews®.
— 10 —
--—.....^Cla^
-L
-M -B
Set the stitch
length
23
4.5
Needle lift
2.0 mm
2.2 mm 2.4 mm
Gap®
1.0 ~ 1.6 mm
Clearance ©
0.05 mm
Hook point
Set screw of hook
shaft gear (small)
Set screw of lower
shaft gear (large)
Set screw
Set screw
Q)
Set screw \
Set screw (B Set screw ®
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
• Position adjustment of needle point
Adjust needle position so that gap between the
upperedgeof needleeyeand the hookpointis(§)
mmwhen the needleIs lifted by@ mm from Its
lowest position shown Inbefore page.
(1) Remove the face plate, loosen the set screw
of needle bar bracket and vertically move the
bar to adjust.
(2) After the adjustment, tighten the set screw.
—11 —
0
-Needle bar
-Needle bar
bracket
Set screw
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
55 Adjustment of feed dog height
Height of feed dog and pressure of presser foot
should be adjusted for individual fabric(s) with the
following cautions:
♦ Fabric will be damaged if the feed dog extends
too high, or pressure of presser foot is too large.
♦ Even stitch length cannot be assured if the feed
dog is too low or pressure of presser foot is too
small.
♦ Feed dog height should be measured at the
point where the needle is at the top position.
For light fabrics
For usual fabrics .
For heavy fabrics .
Approx. 0.8mm from
throat plate
Approx. 1.0mm from
throat plate
Approx. 1.2mm from
throat plate
Adjustment procedure
(1) Lean the machine head backward.
(2) Turn the handwheel by hand and stop when
the feed dog rises to the maximum height.
(3) Loosen the feed bar set screw.
(4) Vertically move the feed bar (in the direc
tion indicated by arrow in the figure) to
adjust it to adequate height.
(5) After the adjustment, tighten the feed bar
set screw.
The feed dog height is factory-adjusted to
1 mm.
— 12 —
2ZZ
22ZZr !
0.8mm
TSi
1.0mm
1.2mm
Set screw
Feed bar
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Relationship between rotating hook
motion and take-up lever motion
When the timing belt (cog belt) was removed for
its replacement, for example, the relationship
between rotating hook motion and take-up lever
motion should be adjusted as follows:
(1)Turn the balance wheel and stop when the
take-up lever is lifted to its top postion.
(2) Lean the machine head backward and make
sure the arrow (timing mark) put on the
timing belt is in line with the black line on
the boss of hook shaft bearing.
(3) If the timing mark is not in line with the
black line, remove the timing belt and in
stall it again to adjust.
] Relationship between hook motion and
opener motion
(1)Turn the balance wheel by hand and stop
when the opener holder is located most
remotely from the throat plate.
(2) Make sure gap between the bobbin case
and the opener is approximately 0.2 mm,
(3) If the gap is too large or small, loosen the
opener set screw @ and adjust position of
the opener.
— 13 —
Black line on boss of
hook shaft bearing
Approx. 0.2mm
Timing belt
ill
Timing mark
Timing belt sprocket
Opener Screw®
Opener holder
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Feed shaft
crank (middle)
[T^ Relationship between needle motion and
feed dog motion
oThe feed dog should bo adjusted so that the
needle can plunge into the feed dog needle hole
at the center of the hole.
(1)Set stitch length to "0"on the stitch length
setting dial.
(2) Lean the machine head backward.
(3) Loosen the feed shaft crank set screw
and(^
(4) Lower the needle to the lowest position.
(5) Adjust the distance between "the pressure
bar and the needle bar to be 13.5, and
tentatively tighten the screws (§) and (b)
of the feed shaft crank.
(6) Check that the right feed shaft crank is con
nected with the link at right angle, as shown
in Figure.
(7) If the connection is not .at right angle, re
move the back cover, loosen the screw ©
and move the needle bar rocking rod in the
arrow direction to adjust.
(8) After the completion of adjustment, fully
tighten the screws (§), (§) and ©.
Screw
Feed shaft
crank(right)
Needle bar-
n..'5
Screw
Pressure bar
Feed shaft
crank (right)
— 14 —
Screw®
'Needle bar
rocking rod
Screw ©
Needle bar
rocking rod
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
Installation of movable knife
1. Initial position of movable knife
{1) Turn the balance wheel and lower the needle bar to the lowest position.
(2) Push the cam follower crank so that the cam roller enters into the thread trimmer cam groove.
(3) Turn the balance wheel until the black mark point on the arm meets the white mark point on the
balance wheel.
Set the cam follower crank at this position with a screwdriver temporarily preventing the cam
roller coming out from the cam groove.
14) Loosen the thread trimmer rocking crank clamp bolts @ and @.
(5) Adjust the movable knife so that the movable knife end slant portion protrudes 0 — 0.5 mm from
the fixed knife, as shown in Figure and tighten the bolts @ and (§) .
Bolt{g)
Thread trimmer
rocking crank
Bolt(D
Thread trimmer
rocking crank
2. Gap between movable knife and bobbin case
hoider stopper
(1) Turn the balance wheel by hand until needle
reaches the lowest position.
(2) With the needle at fhe lowest position, de
press cam follower crank, turn the balance
wheel until the movable knife reaches the
extremity of its stroke.
(3) Manually rotate the inner hook in the direc
tion indicated by arrow in Figure and adjust
gap between the movable knife and the in
ner
hook stopper to about 0.2 mm (the
screws @ and @ should be loosened
for this adjustment).
—15 —
Movable knife
0 ~ 0.5mm
Fixed knife
Movable knife-
^—-Screw
Screw
Hook positioner
Approx.
0.2 mm
inner hook
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
|l^ Adjustment of threadtrimmer cam
(1) Turn the balance wheel by hand until the needles reach the lowest position.
(2) Maintaining the needle position, depress the cam follower crank and put the cam roller into the
groove of thread trimmer cam.
(3) Turning the balance wheel by hand, adjust the thread trimmer cam so that the movable knife
starts moving when the green mark point on the balance wheel comes in line with the black mark
point on the arm.
To adjust, loosen two thread trimmer cam clamp screws @
Cam groove
Cam follower
crank
Cam roller
Screw @
Thread trimmer cam
— 16 —
Green mark point
Black mark
point
Balance wheel
From the library of: Superior Sewing Machine & Supply LLC

OPERATION
|20| Adjustment of thead tension regulator
(1) Turn the balance wheel byhand until the needles reach the lowest position.
(2) Maintaining the needle position, depress the cam follower crank and put thecam roller intothe
groove of thread trimmer cam.
(3) Turning the balance wheel by hand, adjust the thread tension release cam sothat the tension disc
close when the white mark point on the balance wheel comes in line with the black mark point
on the arm.
To adjust, loosen two tension release cam clamp screws @.
(4) Opening degree of tension disc should be adjusted with the tension release roller (g) mounted on
the convexed portion of thread release cam, as shown in Fig.
Toadjust, loosen the screws © anddrawthe wire.
(5) Make fine adjustment by loosening the nut © .
Thread tension
release lever
Screw @
Roller
Thread
release cam
Threadtrimmer ^
cam Screw
(D
(D
Cam follower
crank
Cam roller
-17-
White mark point
Blackmark
point
Balance wheel
From the library of: Superior Sewing Machine & Supply LLC