Brother LH4-B800E- Manuals

LH4-B800E CONTENTS 1. MECHANISM DESCRIPTION .......................................... 1-1 1-1. Needle take-up mechanism ............................................... 1-1 1-2. Upper shaft, lower shaft and rotary hook mechanism ....... 1-2 1-3. Needle zigzag mechanism .................................

LH4-B800E 1 - 1 1. MECHANISM DESCRIPTION 1. MECHANISM DESCRIPTION 1-1. Needle take-up mechanism 1. When the machine pulley q is turned in the direction of the arrow, the rotation is transmitted to the thread take-up crank e that is secured to the end of the upper shaft w . 2. The needle bar crank r ...

LH4-B800E 2 - 1 2. DISASSEMBLY 2. DISASSEMBLY Remove the two screws q , and then remove the cover w . Loosen the set screw e , and then remove the set screw collar assembly r from the lower shaft t . Loosen the set screw y , and then remove the timing pulley assembly u from the lower shaft t . Loose...

LH4-B800E 2 - 16 2. DISASSEMBLY Loosen the screw q , and then remove the pulley assembly w . Remove the screw e , and then remove the synchronizer assembly H80 r from the arm. Remove the two bolts t and the two plain washers y , and then remove the tension pulley assembly u . Remove the screw i and ...

LH4-B800E 2 - 22 2. DISASSEMBLY Remove the screw q , and then remove the lever stopper w . Remove the screw e , and then remove the lever stopper r . Remove the screw t , and then remove the balancer y from the cutter bar fixing plate u . Loosen the set screw i , and then remove the cutter bar fixin...

LH4-B800E 2 - 23 2. DISASSEMBLY Remove the screw q , and then remove tube support U w . Remove the wicks e and r , and then disconnect the oil tube t . Remove the felt y , and then remove the wick u from bush F i . 2-14. Lubrication mechanism Shaft bush mechanism t r r e e w q i u y w

LH4-B800E 2 - 24 2. DISASSEMBLY Needle zigzag mechanism Remove the screw q , and then remove the felt support w from the motor bracket e . Remove the screw r , and then remove the tube support t . t t r r e w q q w

LH4-B800E 2 - 25 2. DISASSEMBLY Oil tubes Remove the fastening band q . Remove the screw w , and then remove tube support M e . Disconnect the oil tube r that is connected to the oil terminal and the plunger pump. Remove the screw t , and then remove the tube support y . Remove the cord holder i , s...

LH4-B800E 2 - 26 2. DISASSEMBLY Remove the screw q , and then remove the cap w and the felt @5 . Remove the screw o , and then remove felt base A r from the wick base support i . Remove the screw e , and then remove the wick base support i . Remove the two screws !4 , and then remove the oil termina...

LH4-B800E 2 - 27 2. DISASSEMBLY Remove the three screws q , and then remove the oil filter bracket w from the bed. Remove the oil tube e that is connected between the plunger and the filter from the oil filter bracket w . Remove the two springs r and the two screws t , and then remove the pump filte...

LH4-B800E 2 - 28 2. DISASSEMBLY Remove the spring q and the screw w , and then remove the rubber presser e from the bed. Remove the wick r from the felt support t . Remove the wick y from the felt support t . Remove the two screws u , and then remove the felt support t from the bed. Remove the end o...

LH4-B800E 3 - 1 3. ASSEMBLY 3. ASSEMBLY After attaching the timing belt to the idle pulley assembly q , insert the collar w . Insert the shaft e , and then install the assembly to the bed with the two set screws r . Install the timing pulley assembly t to the lower shaft y with the set screw u , and...

LH4-B800E 3 - 17 3. ASSEMBLY Install the two retaining rings q to the upper shaft w . Press-fit the ball bearing e as far as the retaining rings q . (Upper shaft assembly r ) Place the timing pulley U assembly t , timing belt y , bobbin winder pulley u and set screw collar assembly i onto the upper ...

LH4-B800E 3 - 23 3. ASSEMBLY Provisionally install the thread guide w to the thread breakage perceiving shaft q with the plain washer e , plain washer r and screw t , and then insert the thread breakage perceiving shaft q into the arm. Provisionally install the thread breakage sensor assembly y with...

LH4-B800E 3 - 30 3. ASSEMBLY Pass the wick q through the collar w as shown in the illustration. Place the collar w onto the bush e as far as the base of the hollow. Insert the spring r into the bush e , and then insert the wick q as shown in the illustration. Push the end of the felt t into the hole...

LH4-B800E 4 - 1 4. Adjustment q w r e (a) (b) t y r (c) 4. ADJUSTMENT [When turning on the power to make adjustments]1. Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presser foot before carrying out adjustments.“Adj” will appear in the numer...

LH4-B800E 4 - 2 4. Adjustment q 18.52 mm w t r e u y 4-1. Adjusting the needle zigzag home position sensor position Reference value Needle bar Presser bar Needle movesto the right N e e d l e m o v e sto the left 1. Turn on the power and set the sewing machine to the home position. Then press the RE...

LH4-B800E 4 - 3 4. Adjustment (1.5) r e w q q w 2 mm 4-2. Adjusting the feed home position sensor position 1. Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presser foot. 2. If the clearance between the feed arm support q and the linear bushi...

LH4-B800E 4 - 5 4. Adjustment r e w q (A) q t y 4-3. Adjusting the presser foot home position sensor position Approx. 1 mm 1. Turn on the power. * Do not set the sewing machine to the home position. 2. Move the trimmer driving arm w in the direction of the arrow to move the upper thread trimmer driv...

LH4-B800E 4 - 6 4. Adjustment t r e w q t r e w q i u y 0.01 - 0.08 mm o 0.3 mm O.K. NG 4-4. Adjusting the needle bar height Needle bar Cutter Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presserfoot.1. Move the needle bar q to its lowest p...

LH4-B800E 4 - 10 4. Adjustment X Y t r e w q i u y 0.3 mm w Push 4-11. Adjusting the knife installation position (Fig. A) (Fig. B) Pulled forward Knife groove Cutter Touching Adjust so that the upper thread trimmer knife and the cutter do not touch when the cutter is pushed down by hand.If the upper...

LH4-B800E 4 - 11 4. Adjustment q e q w 1.5 - 2 mm w The special needle plate has a narrow cutter groove of 0.3—0.4 mm, so use the accessory positioning plate q to adjust the cutter installation position.Furthermore, install the cutter holder w to minimize any play in the cutter during cutting. * If ...

LH4-B800E 4 - 12 4. Adjustment Upper thread trimming adjustment procedure Adjusting the presser foot home position sensor position 4-3 (1) (1) Adjusting the longitudinal feed armassembly position 4-13-1 (2) (2) (1) Adjusting the trimmer driving armassembly position 4-13-2 (3) (3) (2) (1) Adjusting t...

LH4-B800E 4 - 13 4. Adjustment r e q w t r e w 1 mm r e q w r e q w r w 1 mm 4-13-1. Adjusting the longitudinal feed arm assembly position 4-13-2. Adjusting the trimmer driving arm assembly position The following should be checked before adjusting the upper thread trimming. Aligned 1. Turn on the po...

LH4-B800E 4 - 15 4. Adjustment u y t q e w r e q 4-13-5. Adjusting the cutting depth of the upper thread scissors Clearance 0--0.5 mm Cam 1. Turn off the power (with the feed mechanism at the home position), and then slowly move the trimmer driving arm q forward until the driving arm roller e is at ...

LH4-B800E 4 - 17 4. Adjustment 0.5 mm 0.5 mm 0.5 mm 0.5 mm r r e w q q w (A) (B) (B) (a) 0.5 mm (a) (b) (b) (A) (C) 4-13-7. Adjusting the upper thread scissors gradual opening timing Starts touching at 1.5—2.5 mm Turn on the power and set the sewing machine to the home position. Then press the RESET...

LH4-B800E 4 - 19 4. Adjustment (A) (B) r e w q 1 mm e y t y (A) (B) e q w (A) (B) e w 1 - 2 mm 4-14. Adjusting the lower thread trimming 4-14-1. Adjusting the lower thread trimmer fixed knife engagement amount Lower thread trimming complete 1. With the power turned off, move the lower thread trimmer...

LH4-B800E 4 - 24 4. Adjustment 2 mm r e q w (A) y t e r (B) 1 mm 1 mm 0.1 - 0.5 mm e w e !0 o i u 4-16. Adjusting the thread breakage detector Touching Section (A) Section (B) 1. Tighten the lever stopper q inside the slotted hole. Loosen the screw w , and then adjust so that the distance (A) at the...

LH4-B800E 4 - 26 4. Adjustment w q r e w q w w w F = 98 N (10 kgf) t 4-19. Adjusting the upper thread feeding amount 1. Loosen the screw q , and then turn the tension take-up lever w to adjust the upper thread feeding amount. * Move the trimmer driving arm by hand and check that upper thread feeding...

LH4-B800E 4 - 28 4. Adjustment t r e w q y w q 10 - 14 mm 4-23. Adjusting the needle up stop position 1. The needle up stop position is adjusted so that the index mark w on the machine pulley q is inside the mark r on the belt cover e . If adjustment is necessary, loosen the screw t of the machine p...

LH4-B800E 5 - 1 5. Troubleshooting guide Cause Check Solution page Needle Needle facing Reattach needle properly As viewed from the direction of theface plate, attach needle so that the notched part of needle faces frontward - (Instruction) Needle installationheight Install the needle at the correct...

LH4-B800E 5 - 5 5. Troubleshooting guide Cause Check Solution page Lower threadretainer Lower thread retaining amount Adjust the lower thread retaining amount. 4-19 Lower thread clamp Lower thread clamp timing Adjust so that the lowerthread clamp plateopens when the feed mechanism moves 6 --7 mm. Ad...

LH4-B800E 5 - 10 5. Troubleshooting guide 5-9. Unraveling of thread trimmed by upper thread trimmer assembly 5-10. Needle thread mis-trimming Check burr on upperside here Check burr here Cause Check Solution page Upper thread trimmer assembly Upper thread trimmer assembly position Refer to "5-8....

LH4-B800E 5 - 11 5. Troubleshooting guide Cause Check Solution page Upper thread trimmer assembly Upper thread trimmer assembly position Refer to "5-8. Needle thread runout" Upper thread scissors operating force Adjust so that scissors M open when theprojection is pressed with a force of 4 N...

LH4-B800E 5 - 17 5. Troubleshooting guide Cause Check Solution page Feed pulsemotor Cord connection Check the cordconnections andcontacts. - Upper thread scissors Upper thread scissors position Remove and re-install the upper threadscissors. Projection on scissors M is inserted. * Always make sure t...

LH4-B800E 5 - 18 5. Troubleshooting guide 5-18. Needle does not zigzag or noise occurs when needle zigzags 5-19. Sewing machine stops during sewing Cause Check Solution page Zigzag home position sensor Zigzag home positionsensor position Adjust the zigzag home position sensorposition. 4-2 Stopper St...

LH4-B800E 6 - 1 6. ELECTRIC MECHANISM 6. ELECTRIC MECHANISM 6-1. Precautions at the time of adjustment Pay attention to the following when opening the control box for maintenance. ■ Electric shock Some large capacitors may have a high voltage remaining in them for up to 5 minutes after the power is ...

LH4-B800E 6 - 2 6. ELECTRIC MECHANISM 6-2. Components inside the control box and the operation panel The following are brief explanations of components inside the control box. For details on connections, refer to "6-9. Control circuit block diagram". - Main circuit board This circuit board i...

LH4-B800E 6 - 23 6. ELECTRIC MECHANISM Setting item Work clamp size: 7.3 × 75 mm (6.0 × 70 mm) Work clamp size: 7.3 × 36 mm (6.0 × 32 mm) Work clamp size: 7.3 × 24.5 mm (6.0 × 20 mm) Work clamp size: 6.8 × 36 mm (5.4 × 32 mm) Work clamp size: 6.8 × 24.5 mm (5.4 × 20 mm) Panel DIP switches B-7 and B-...

LH4-B800E 6 - 26 6. ELECTRIC MECHANISM 6-6. Description of machine motor parameters * To change the machine motor parameters, press and hold the ENTER key and then turn on the power. Machine motor parameter setting mode will then start. * Do not change the default values for the machine motor parame...

LH4-B800E 6 - 34 6. ELECTRIC MECHANISM 6-9. Control circuit block diagram POWER P6 B10P-VH 10 MP0V 9 MP0V P0V M55V 8 M55V 7 SOV 6 5 E24V 4 P0V 3 +55V 2 +55V 1 PER P3 VALV P4 Green/Yellow Leg Green/Yellow White Red OUT220V IN240,380,400,415V Emergency stop Blue Black Brown WhiteBlack Red home positio...

SERVICE MANUAL Printed in Japan 118-H80 I1050811H 2001.07. H (1) BROTHER INDUSTRIES, LTD. 15-1, Naeshiro-cho, Mizuho-ku, Nagoya 467-8561, Japan. Phone: 81-52-824-2177