Brother BAS-370 User manual

•
SERVICE MANUAL
FOR
BAS-370
BAS-375
PROGRAMMABLE ELECTRONIC
PATTERN SEWER
From the library of: Superior Sewing Machine & Supply LLC

•• •••• CONTENTS •••••o
DISASSEMBLY AND ASSEMBLY
FOR TRANSPORTING .......... .
MECHANICAL DESCRIPTIONS ..
[]Needle bar and thread take-up, lower
shaft, and rotary hook mechanisms •
[Z]Presser plate mechanism .....••••••
[ID Drive, feed mechanism ..•.•••••..•
!!]Intermittent presser foot mechanism
[§]Thread trimmer mechanism ••..•..•.
[§]Auto eject mechanism •••••.•.•..••
11] Bottom mechanism •.••••.••••.•..
DISASSEMBLY ................. .
[]]Covers •••••.•••..••••.•••..•.•
lZJPresser plate mechanism ••••••••.•.
~Needle plate mechanism ••••..•.••.
[!]Rotaryhook mechanism ......••••.
liD Bottom mechanism •.•••••..••.•..
liD Thread trimmer mechanism
11] Intermittent presser foot mechanism
liD Needle bar and thread take-up
mechanism
................ • ...
ASSEMBLY ..................... .
[]]Needle barand thread take-up
mechanism ••.•••••••••••.••.•
[Z]Intermittentpresser foot mechanism
[IDThread trimmer mechanism ...•.••.
[!]Bottom mechanism •.••.••..••.••.
[ID Rotary hook mechanism •••..••.•..
liD Needle plate mechanism ••...•..•..
llJCovers ....•....•..•...•....••.
1-1
1-2
1-2
1-3
1-4
1-5
1-6
1-7
1-8
2-1
2-1
2-2
2-2
2-3
2-3
. 2-4
2-5
2-6
3-1
3-1
3-2
3-3
3-4
3-5
3-6
3-7
STANDARD ADJUSTMENTS . .. . 4-1
[]]Adjusting the needle bar stroke • • • • . 4-1
~Adjusting the needle bar height • . • • . 4-1
[IDAdjusting the clearance between the
needle and the rotary hook . . • • • • • 4-2
[!]Adjusting the presser foot height • • . • 4-2
i:IDAdjusting the presser foot • • • . • • • • . . 4-2
[§]Adjusting the intermittent presser
foot lift stroke • • • . • • • • • . • . • . . . . 4-3
[l]Adjusting the presser plate height 4-4
!IDAdjusting the presser plate moving speed
~Adjusting the presser plate pressure ...
lrn!Adjusting the bottom plunger ••••••
lll!Adjusting the autoejectmechanism ••
~Adjusting the thread trimmer •••••••
~Adjusting the backlash ••.••••.••••
IM!Adjusting the belt tension ••••••.•••
ll§lAdjusting the timing between the
needle and feed mechanism
li§JAdjusting the home position •.••.••
lll]Adjusting the overtravel ••.•••••••
ELECTRICAL EQUIPMENT ...... .
[]]Fuse ••.••••••.••••.•••.••••.••
lZJPower supply equipment ••••••••••
@!Circuit board ••••••.•••••••••••••
[!]Replacing the circuit board •••••••••
liD LEDs of servo motor driver ..•..•.••
liD Function and position of sensors .••••
ll]Connectorsexplanations ••.•••••••
[IDSetting the DIP switch •.•.•••.•..
~Setting the memoryswitch •••.••••
lrnl Using the optional output •••••••••
lll1 Diagnosis flowchart •••.••••••••.
OPTION ................ ·~· ...... .
[i]Subclamp •••.•.•.••.•••••••••••
[Z]Beam sensor thread breakage detector
[IDNeedle thread presser assembly •••••
[!]Two-stagethread tension ••••.•.••.
liD Intermittent presser foot control
mechanism ••...•.••••••.•••••
IIDJig pattern sensor ••••••••••••••••
4-4
4-5
4-5
4-6
4-7
4-8
4-9
4-10
4-10
4-12
5-1
5-1
5-2
5-3
5-5
5-6
5-7
5-10
5-12
5-13
5-14
5-15
6-1
6-1
6.:.2
6-4
6-5
6-6
6-8
TROUBLESHOOTING GUIDE . .. . 7-1
ERROR CODE LIST
CONTROL CIRCUIT
BOARD
DIAGRAM
7-4
7-5
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DISASSEMBLY AND ASSEMBLY FOR TRANSPORTING
The sewing machines are 1820 mm wide for BAS-370, 2620 mm wide for BAS-375, and they both are 1415
mm long, and 1363 mm high. The sewing machines are disassembled to make them easy to transport.
Assemble
the sewing machines referring to item .. [§] Needle plate mechanism" in ASSEMBLY.
<BAS-370 sewing area: 800x400 mm>
The above figure shows the sewing machine without
the needle plate, the rack cover,. the oil pan, and the
presser hinge, when the needle plate support
bracket is folded.
<BAS-375 sewing area: 1200x400 mm>
The above figure shows the sewing mathine without
the needle plate, the rack cover, the oil pan, and the
presser
hinge, when the needle plate support
bracket is folded.
1-1
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MECHANICAL DESCRIPTIONS
II1 Needle bar and thread take-up, lower shaft, and rotary hook mechanisms
1. Needle bar and thread take-up mechanism
1) When the motor 0 rotates in the direction of the arrow, the motion is transmitted to the thread
take-up crank@) through the uppershaft@.
2) The needle bar crank e secured to the thread take-up crank @) moves the needle bar clamp @ up and
down via the needle bar crank rod 0.
3) The needle bar fl attached to the needle bar clamp @ is guided by needle bar bushes (U) @ and (D) @,
and the needle bar guide slide block@, and smoothly moves up and down.
2.Lowershaftand rotary hook mechanism
1) When the motor 0 rotates in the direction of the arrow, the motion is transmitted to timing pulley (U)
ID through the uppershaft@.
2) Timing pulley (D) @ secured to the lower shaft @ transmits the motion to the lower shaft @ via the
timing beltm.
3) The spiral gear @ is secured to the tip of the lower shaft @ , and engaged with the pinion aJ attached
to the rotary hook shaft @. When the lower shaft @ rotates onetime, the rotary hook shaft @ rotates
two times.
4) The rotary hook@ secured to the tip of the rotary hook shaft@ rotates similarly.
, <To turn the pulley manually >
When the pulley® is pressed in the direction of the arrow, the stopper lever @1 is locked, and the pulley
shaft gear m is engaged with the gear fEJ, the upper shaft @ can be turned manually. When the
stopp.er lever W is pulled in the direction of the arrow, it is unlocked.
1-2
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~Presser plate mechanism
1) When the air pressure is supplied to the cylinder @ from the air tube 0, the presser arm front @)
secured to the cylinder@ is pushed forward, and the motion is transmitted to link {A) 0.
2) Link {A) 0 is connected to link (B) 0 via the stud @),and also connected to the presser arm 6 via the
clevis pin@. The presser arm 6 is lowered by pivotingthe clevis pin@).
3) When the presser arm 6 is lowered, and the clevis pin @,the stud @,and the cylinder support shaft «!)
are arranged in a line, the material pressing pressure is at its maximum, and the material is securely held.
4) When the air pressure is supplied to the cylinder@ from the air tube ID, the presser arm 6 rises.
1-3
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@]Drive, feed mechanism
<X direction>
1) When the AC servo motor 0 rotates, the motion is transmitted to the X-Y timing pulley 9 through the
gear@ and the X-gear@, and the X-timing belt0 operates.
2) The X-timing belt 0 operates the ball spline f) via the X-driving timing pulley@}.
3) The ball spline 6 operates the rack gear@) via the X-driving gear@.
4) The rack gear @> is secured to the X-movable plates ([!),and the X-movable plates ([!) are guided by the
LM guide ill. The rotating motion of the AC servo motor 0 is converted to X-directioli movement.
<Y direction>
.-h
r--- :
L ..
1) When the AC servo motor@ rotates, the X-Y timing pulley@ rotates via the gear@ and theY-gear ID,
and theY-timing belt@ operates.
2) TheY-timing belt@ rotates theY-shaft (ID via theY-driving timing pulley 0).
3) When theY-shaft@ rotates, the timing belt@) operates via the Y-R timing pulley@.
4) The timing belt tiD is secured to the belt retention plate fD, which is secured to the X-hold frame 0.
5) The X-hold frame fh is guided by the LM-guide@, and moves in theY direction.
1-4
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II) Intermittent presser foot mechanism
<When the pulley rotates>
1) When the upper shaft .0 rotates, the presser lifter cam @ attached to the upper shaft 0 moves
eccentrically, the intermittent presser connecting rod@ oscillates intermittent feed arm (R) 0.
2) The oscillation of intermittent feed arm (R) 9 is transmitted to link (L)@) through U-UD feed arm (L) 0.
3) Link (L) €) oscillates the intermittent lever @ guided by the intermittent support & · and the
intermittent guide@) .
4) The oscillation of the intermittent lever@ is transmitted to the presser bar clamp ((i), and the presser bar
clamp ((i) moves up and down.
<When the presser foot is raised>
1) When the valve operates, and the presser bar lifter cylinder (D operates presser bar lifter arm (B) @ in
the direction
of the arrow, the presser bar lifter connecting rod@ is pulled in the direction of thearrow.
2) The presser bar lifter connecting rod @ operates the presser bar lifter lever ID in the direction of the
arrow, and
raises the ·presser bar clamp ®.
1-5
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~Thread trimm.er mechanism
1) When the thread trimming signal is sent, and the valve operates, the thread trimmer cylinder 0
operates in thedirection of the arrow.
2) The thread trimmer cylinder 0 operates the movable knife holder @) in the direction of the arrow via
thethread
trimmer connecting rod@ .
3) The movable knife e secured to the movable knife holder @) is engaged with the fixed knife 0 ,then
thethread
is trimmed.
1-6
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[§]Auto eject mechanism
1) When the cassette plate assembly 0 is attached to the feed mechanism, and either the ejectorsensor @
detects the two positionings {A) @),or the presser lifter pedal is depressed, the valve stops operating and
the ejector cylinder9 operates in the direction of the arrow.
2) The motion is transmitted to the cylinderconnecting plate 0 and the guide plate @ which are attached
to the ejector cylinder e.
3) Because the guide plate ® is guided by the pin of the pin plate assembly fi, the horizontal movement
of the ejector cylinder 9 is converted to vertical movement, and the motion is transmitted to the guide
plate@.
4) When the guide plate ® pulls into positioning {A) @),the cassette plate assembly 0 is secured to the
feed mechanism.
5) When sewing is completed or the presser lifter pedal is depressed, the valve operates, and the ejector
cylinder 9 moves in the opposite direction to the arrow. The guide plate ® pushes positionin·g {B) @,
and the cassette plate assembly 0 comes off the feed mechanism.
1-7
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11] Bottom mechanism
1) When the valve operates at the start of sewing, the bottom cylinder 0 operates in the direction of the
arrow.
2) The bottom lever @ attached to the bottom cylinder 0 transmits the motion to the bottom plunger 0
via the beltshift bar@.
3) When the valve stops operating at the end of sewing, the bottom cylinder 0 moves in the opposite
direction to the arrow, and the bottom plunger 0 returns to its original position.
1-8
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DISASSEMBLY
II] Covers
1) Remove the screws, the front cover 0, the frame side covers@, and the rear cover@).
2) Remove the screws, and tables {A) 0 and (D) 0.
3) Remove the screws, and the table cover®.
4) Remove the nut 6, and the operation box assembly@).
NOTE: The operation box assembly@ is connected to the cord. Be careful when removing it.
5) Remove the screws, and tables {B)@ and {C) «i>.
6) Remove the screws, the belt presser plates Q), and the dust belt@.
7) Remove the screws, the arm motor cover@, the arm rearcover ID, and the arm front cap {G).
8) Remove the screws, the eye guard@, and the face plate 4D.
2-1
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~Presser plate mechanism
@1 Needle plate mechanism
2-2
1) Remove the four bolts 0, and the presser plate
assembly@.
2) Release the air, and remove the cassette plate
assembly@ from the auto eject mechanism e.
1) Remove the screws, the needle plate left 0 ,
the needle plate inner @ , and the needle plate
right@.
2) Remove the bolt 9, the four needle plate
supports €)
1 and
two needle plate supports (B)
@_
NOTE: For the BAS-375, remove the bolt f)
1
and the needle plate supportside@.
3) Remove the four bolts@.
4) Loosen the four bolts®.
5) Fold the needle plate support bracket ID inside
(in the direction of the arrow).
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[!]Rotary hook mechanism
~ Bottorrt mechanism
2-3
1) Remove the two screws 0, and the needle
plate@.
2) Remove the screw @), and the rotary hook
bobbin case holderS.
3) Loosen the three screws 0, and the rotary hook
@.
Be sure to release the air.
1) Remove thestop rings 0, and the link pin@.
2) Remove the stop ring@), the washers 0 and 0,
and the bottom lever 0.
3) Remove the two airtubes G.
4) Remove the stop ring @,the washer @, and
the bottom cylinder®.
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[§]Thread trimmer mechanism
Be sure to release the air.
1) Remove the two screws 0, and the needle plate@.
2) Remove the two screws@), and the movable knife 0.
3) Remove the two bolts@, and the fixed knife presser@.
4) Remove the screw f), and the fixed knife@.
5) Remove the screw@, and the lower thread finger 4ll>.
6) Remove the bolt ID, the stud screw@, and thethread trimmer connecting rod@.
7) Remove thestop ring ID, and the movable knife holder@.
8) Remove the two airtubes@ .
9) Remove the set screw Q), the support lever shaft@, and the thread trimmer cylinder assembly @.
2-4
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[Z]Intermittent presser foot mechanism
1) Remove thethree screws 0 I and the face pi ate @.
2) Remove the adjust screw@)
1
the spring guide01 the spring 0 I and the washer@.
3) Remove the screw f)
1 and
the presser foot@.
4) Loosen the screw €>
1 and remove the presser bar
4ID by pulling it downward.
5) Remove the two boltsmI the intermittent guide@ I and the U-U Dfeed lifter lever roller@.
6) Remove the stop ring ffi.
7) Loosen the set screw@I and remove the set collar(@.
8) Remove the intermittent supportassembly {f}.
9) Remove the stud screw@.
1 0) Remove the rollershaft@I and the intermittent lever fli> along with link {L) fD .
11) Remove the presser barclamp 0.
2-5
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(I]Needle bar and thread take-up mechanism
1) Remove thethree screws 0, and the face plate@.
2} Remove the set screw@, the needle e, and the needle barthread guide 0.
3) Remove the oil cap@.
4) Loosen the screw f), and remove the needle bar@ from the arm by lifting it upward.
5} Remove the screw (left-hand screw} @,and the needle bar crank rod ® along with the needle bar clamp
Q). Be sure not to drop the needle bearing@ and the needle bar guide slide block@.
NOTE: The needle bearing@ is not used for the thick material specification.
6) Remove the oil cap ffi.
7) Loosen the two set screws @, and remove the needle bar crank ®. Be sure not to drop the needle
bearing @ and the washer@.
8) Loosen the set screw ®,and remove the thread take-up support shaft W, and the thread take-up f1).
2-6
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ASSEMBLY
[I] Needle bar and thread take-up mechanism
1) Attach the thread take-up 0 to the arm using the thread take-up support shaft @,and tighten the set
screw@.
2) Insert the needle bearing 0 into the thread take-up 0. Holding the washer €) with one hand, insert
the needle bar crank @ into the thread take-up 0, the needle bearing 0, and the washer €), and then
tightenthe
two set screws fi so that they are aligned with thescrew flats of.the needle barcrank@.
3) Attach the oil cap@.
4) Insertthe needle bar crank rod @) into the needle bearing «!>,and secure them using the screw (lefthand
screw)
ID.
NOTE: The needle bearing«!> is not used for thethick material specification.
5) Pass the needle bar guide slide block 0 through the needle bar guide of the machine arm, and insert
the tip of the needle bar clamp@.
6) Insertthe needle bar 4D into the arm from the top of the machine, pass it through the needle bar clamp
@,and temporarily tighten the screw~.
7) Attach the oil cap@.
8) Attach the needle barthread guide 0 and the needle tiD to the tip of the needle bar ID, and secure the
setscrew@.
3-1
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~Intermittent presser foot mechanism
1) Slide the guide part of the presser bar clamp 0 into the arm channel. Insert the presser bar @ into the
arm from the top of the machine head. Then temporarily tighten the screw @. (The screw hole of the
presser bar@ should be facing toward the front.)
2) Insert the intermittent lever 9 along with link (L) 0 into the shaft of the presser bar clamp 0, then
secure the rollershaft ®.
3) Fit the U-UD feed lifter lever roller f'J into the roller shaft @, attach the intermittent guide @ to the
arm, and temporarily tighten the bolt@.
4) Move the presser bar@ up or down until it moves smoothly, and attach the intermittent guide @ to the
presser bar@ using the bolt@.
5) Insert the shaft of the intermittent support assembly ® into needle bar crank bush (R), and put the
intermittent supportassembly® into the U-U Dfeed lifter leverroller ID.
6) Attach the set collar 0, and tighten the set screw®.
7) Place the stop ring ID on the roller shaft@.
8) Attach link (L) 0 to U-UD feed arm (L) (f) using the stud screw@.
9) Place the washer (ID on the presser bar @. Insert the spring @ and the spring guide f1i). Tighten the
adjustscrew m.
1 0) Attach the presser foot @) to the presser bar @ using the screw @.
3-2
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@)Thread trimmer mechanism
1) Attach the thread trimmer cylinder @ to the bed using the support lever shaft 0, and tighten the set
screw@.
2) Attach the two airtubes a to the two elbows €) of the thread trimmer cylinder@.
3) Place the movable knife holder@ on the bed, and attach the washer fi and the stop ring@).
4) Attach the thread trimmer connecting rod@ to the thread trimmer cylinder@ using the bolt@).
5) Attach the thread trimmer connecting rod ® to the movable knife holder @ using the stud screw 0).
Makesure that the movable knife holder@ moves smoothly.
6) Attach the lower thread finger@ using the screw@.
7) Attach the movable knife@ to the movable knife holder@ using the two screws ID.
8) Insert the fixed knife~ into the bed, and then tighten the screw tTl.
9) Attach the fixed knife presser tiD using the two bolts @.
3-3
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[4]Bottom mechanism
1) Attach the bottom cylinder 0 to the cylinder support shaft@ using the washer@) and the stop ring 0.
2) Fit the bottom lever @} into theY -type fitting 0 of the bottom cylinder 01 and secure them using the
link pin fi and the stop ring@.
3) Pass the bottom lever @} through the belt shift bar @1 and secure them using the washers «!> and 0),
and the stop ring @ .
4) Fit the two airtubes t0 on the MS elbows@ of the bottom cylinder 0.
3-4
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