Brother LZ2-B852, Service Manual

Page 1: ...SERVICE MANUAL FOR LZ2 B852 LZ2 B853 LZ2 B854 r BROTHER INDUSTRIES LTD NAGOYA JAPAN From the library of Superior Sewing Machine Supply LLC ...

Page 2: ... position Front and Back adjustment 16 11 Stitch lenght adjustment 16 TI Reference position adjustment lever Needle position adjustment 17 Zigzag width reference position adjustment 18 II Zigzag regulator position Front and Back adjustment 19 I Needle and feed timing adjustment 20 Adjustment of needle sidewise movement 20 II Needle and rotary hook timing adjustment 21 ID Presser foot height adjust...

Page 3: ...edle bar f up and down 5 Finally the thread take up lever 0 is also driven via the needle bar crank stud 0 IT LOWER SHAFT AND ROTARY HOOK MECHANISM I When the machine pulley 0 is rotated in the d irection of the arrow timing pulley U e which is connected to the upper shaft f rotates 2 ext timing pulley D 0 connected to the lower shaft 0 is rotated by timing pulley Ue via the timing belt 0 3 Timing...

Page 4: ...y model LZ2 B854 4 The needle vibra ting rod 0 is connected to the cam guide O a nd pivots on the zigzag controlG to shift right a nd left models LZ2 8852 a nd 8853 The needle vibrating rod 0 is connected to the roller guide a nd pivots on the zigzag control G to shift right a nd left model LZ2 8854 5 T he j oint 4D connected to the needle vibra ting rod 0 relays the rightjlcft shift ing motion of...

Page 5: ...d driving lever 8 moves in direct relation to the feed regulator 8 4 The motion of the feed rack crank 8 is then transmitted to the feed bar assembly 0 via the feed drive shaft 8 5 The end of the lower shaft 0 is the eccentric connecting link stud and vertically drives the feed bar assembly 8 by means of the upper feed link 8 The action of steps 4 and 5 determines the movement of the feed dog I wh...

Page 6: ...e oil pan raises the knee lifter connecting rod 0 and raises the knee lifter lifting link e via the knee lifter horizontal shaft 6 The knee lifter lifting link e is connected to the needle bar clamp 0 TENSION RELEASE MECHANISM I When the presser foot has been raised by the knee lifter 0 the tension release lever 8 and screw 8 riding on the knee lifter horizontal shaft 8 are raised 2 The tension re...

Page 7: ... with packing to prevent oil leaks Arm oil shield 0 prevents oil from spraying towards the face plate Oil is supplied to the gear box cover CJi side of the machine from the oil tank 8 Ill Oil Pump Mechanism I The pump gear f turns when the gear 0 attached to the lower shaft turns 2 When the pump gear f turns oil is pumped by the screw lifter part bottom end of the rotating shaft 8 The oil passes t...

Page 8: ...Loosen the screw 8 and remove the presser foot 5 Remove the bad slide C 6 Remove the two screws 0 and remove the needle plate fD 7 Remove the two screws 4D and remove the needle plate fD IIJ ROTARY HOOK I Remove the two screws 0 and remove the feed dog f 2 Tilt the machine 3 Remove the screw 8 and remove the rotary hook position bracket 0 4 Loosen the two screwsO and remove the rotary hook 0 6 Fro...

Page 9: ...m that the two collars 8 move 3 Loosen the screw 8 4 Loosen the screw 8 5 Pull the feed drive shaft 8 to the left and remove 6 Now the two collars 8 and drive shaft arm assembly 8 can be removed 7 Refer to page 13 for felt 0 and wick 0 replacement 7 From the library of Superior Sewing Machine Supply LLC ...

Page 10: ...ar 0 remove the presser bar clamp I and link assembly together r 6 After removing the screw 1 remove the presser bar 0 from the top Be careful not to lose the presser bar ball bearing CD on the top of the presser bar 0 Needle Bar 7 Remove the screw 8 and remove the needle bar thread guide 8 8 Loosen the screw e and remove the needle bar 8 from the top When the needle bar 8 is removed the needle ba...

Page 11: ...ed regulator stud e 4 While depressing pin 8 with a screwdriver remove the length control dial Be careful not to lose the pin 8 or spring C 5 Take the timing belt off of timing pulley D 4D 6 Raise the machine 7 Loosen the two screws 0 and remove the machine pulley assembly G 8 Take the timing belt off of the arm 9 From the library of Superior Sewing Machine Supply LLC ...

Page 12: ...0 firmly onto pulley D 0 7 Insert the spring 8 and pin 0 and install the length control dial C Mount the edge of the length control dial into the Y groove of the backstich unit 8 Mount the feed regulator stud 41 in link D and feed regulator lever D and tighten it in place with mounting screw 4D 9 Mount the reverse shaft 4B from the arm side pass it through feed regulator lever U 4J and secure with...

Page 13: ...k stud I and needle bar connecting link e with screws CB and 48 Presser Bar 6 Insert the presser bar 8 into the arm chin part and screw set screw e into the presser bar CJ 7 Hook the link tD hole onto the horizontal shaft 8 Pass the presser bar Cl through the presser barclamp C1 and temporarily tighten set screw 1 8 Set the presser bar ball bearing 8 onto the top of the presser bar Cl Tighten adju...

Page 14: ...st the front back position of the needle bar I Loosen screw 8 depress pin F and orR and move the needle bar crank rod assembly 0 so that the needle tip is centered front and back in the needle hole of the needle plate 2 Make sure there is no play in the forward back direction of the needle bar crank rod assembly and that it moves lightly when the needle zigzags 3 Firmly tighten set screw 8 Adjust ...

Page 15: ...rew remove the feed bar hinge pin and replace 7 Adjust the needle and feed timing I On models LZ2 8852 8853 and 8854 On 8852 set the mark on the thread take up lever 8 to the mark on the face plate on 8854 set it to E on model 8853 center the mark between the and marks 2 After properly positioning the mark on the thread take up lever 8 loosen the two set screws CD and align the marks on the eccent...

Page 16: ...ews 0 6 Install the needle plate 0 with the two screws 1 7 Set the length control dial to the maximum setting 8 Adjust the centering of the feed dog in the needle plate Loosen set screw e and adjust the front back and right left gaps with the feed driving shaft arm 41 so that the feed dog 8 does not strike the needle plate 0 when the machine pulley is turned 9 Adjust the feed dog height and bias F...

Page 17: ...3 Install the slide plate 0 4 Install the presser foot 8 with set screw 9 5 Install the needle 0 with set screw 8 6 Install the a rm top cover 0 with eight screws 0 7 Install the thread take up guard cover 4i with two screws 4 15 From the library of Superior Sewing Machine Supply LLC ...

Page 18: ... sure the reverse lever does not move up ordown lfthe reverse lever 8 moves loosen set screw 0 and turn the length control dial counter clockwise back Then retighten set screw 0 and check for any vertical movement in the reverse lever 8 Repeat this operation until the reverse lever 0 will not move when the length control dial is turned all the way in 2 Turn the machine pulley and make sure the fee...

Page 19: ...justing lever 8 is set to the ma rk bottom the needle will move to the right position I Set the zigzag lever to 0 2 Set the needle adj ustment lever 8 to a level position Align the reference marks on bushing L 0 i e the lines on the large a nd sma ll bushings If the lines are not a ligned loosen set screw 0 a nd adjust the needle position set spring 0 so that the needle position adjustment lever e...

Page 20: ... set screw 0 a nd move the needle vibra ting lever e up or down adjusting to the desired zigzag width Remember to tighten the set screw 0 after adjustment 2 The figures in the scale in the front a rm cover indicate zigzag width in mm Maximum zigng width is 8 mm e Model LZ2 B854 Zigzag width Model LZ2 B852 Model LZ2 B853 Model LZ2 B854 o 5mm o amm o a mm If the above adjustments cannot be made make...

Page 21: ...plate R 2 Move the zigzag lever 0 a ll the way to the right 3 Loosen set screw 6 and adjust the crank assemby angle so tha t the needle will not move 4 Retighten set screw 6 The stiffness in the zigzag lever 0 action can be adjusted with set screw fD Adjust so that the zigzag lever 0 will not move during machine operation a nd so that the zigzag lever 0 moves smoothly when the zigzag width is cha ...

Page 22: ...k with the or marks on the face plate Then loosen the two set screws 0 and align the marks on the eccentric wheel 8 and eccentric cam 0 After the adjustment is completed firmly tighten the two set screws 0 Put a pointed screw 8 into the P marked screw hole on the eccentric cam 0 and tighten the screw into the lower shaft screw stop ADJUSTMENT OF NEEDLE SIDEWISE MOVEMENT I Loosen the set screw 0 in...

Page 23: ... 8 to the furthest left position At this time check that the clearance between the upper lip of the needle hole and rotary hook point 0 is between 0 1 I V 0 5 mm 5 If the clearance is not correct loosen the set screw 8 and adjust by raising or lowering the needle bar 8 After adjustment firmly tighten all of the set screws 8 8 I Ql PRESSER FOOT HEIGHT ADJUSTMENT Make adjustment after turning the po...

Page 24: ...JUSTMENT Highest position 1 r r r 1 0 mm Highest position Lowest position Feed Dog Height Adjustment Weaker Standard r 2llllllllllll a j 1 0 mm Front lowered r j 1 Standard height when the feed dog 0 is raised to its highest position above the needle plate is 1 0 mm 2 Loosen the set screw 8 turn the feed bar lifting link hinge pin 8 and adjust the feed dog to a height 1 0 mm above the needle plate...

Page 25: ...cing the rotary hook always adjust the needle guard position Refer to Inset A 4 Adjust so that the edge of the bobbin case stop 8 is installed between 0 t V 0 5 mm below the end of the rotary hook bracket dotted line of the inner hook Refer to Inset B Make sure the end of the bobbin case stop 8 does not extend to the right beyond the end of the rotary hook bracket dotted line 5 Install the feed do...

Page 26: ...n the nut 0 a nd adjust the tension by turning the screw f 0 ill ADJUSTMENT OF THE QUANTITY OF THE BOBBIN WINDING X 0 X I Push the bobbin fu lly onto the bobbin winder spindle 0 2 Thread the machine as shown in the picture at the left winding the thread o nto the bobbin several times in the direction of the a rrow 3 Press the bobbin winder lever L f onto th e bobbin and run the machine When the th...

Page 27: ...Rotary hook point bent or crushed Presser foot pressure is too great Improper feed dog height Improper lower thread ten sion Improper upper thread ten sion Improper thread take up spring tension eedle incorrectly installed cedlc bent cedlc tip crushed Repair the rotary hook t 1 point or replace it with a new 21 Presser foot pressure Feed dog height Lower thread tension Upper thread tension Thread ...

Page 28: ...NDUSTRIES lTD HEAD OFFICE No 35 9 CHOME HORITA DORI MIZUHO KU NAGOYA JAPAN 467 CABLE BROTHER NAGOYA TELEX BROTHER 4473696J J59743 I 21201 J Printed in Japan From the library of Superior Sewing Machine Supply LLC ...