JUKI HZL-12Z, Service Manual

Page 1: ...Page 1 19 Original issue Jun 2012 Service Manual HZL 12Z Model HZL 12Z ...

Page 2: ...EADER 5 PRESSER FOOT HEIGT 6 NEEDLE POSITION STRAIGHT STITCHING 7 NEEDLE SIDE MOTION 8 FEED DOG CLEARANCE TO NEEDLE PLATE HOLE 9 NEEDLE TIMING TO SHUTTLE 10 NEEDLE CLEARANCE TO SHUTTLE 11 SHUTTLE SHAFT RATTLE 12 THREAD TENSION 13 ADJUSTING MOTOR BELT TENSION 14 ADJUSTING BUTTONHOLE PITCH BALANCE The parts in the pictures can be looked differently as what they are ...

Page 3: ... 2012 Service Manual HZL 12Z Model １ DISASSENBLING OUTER PARTS 1 1 Removing a face cover Take out 2 screws and remove a face cover 2 Removing a front cover 1 Take out 2 screws on a bottom surface 2 Take out 4 screws of a back face ...

Page 4: ...12Z Model 1 DISASSENBLING OUTER PARTS 2 3 Take out 2 screws of a thread guide plate Loosen one of them and take off thread guide plate 4 Take out 2 screws and take off a switch cover 5 Remove front and back covers with a small screw driver Just loosen it ...

Page 5: ...NG OUTER PARTS 3 6 Extract a length control dial 7 Take off a side on connection putting a hand in a hole of length control dial Take off a connection of a needle bar 8 Take off a front cover Including a shuttle cover Disconnect this connector and you can take off a front cover ...

Page 6: ...nual HZL 12Z Model 1 DISASSENBLING OUTER PARTS 4 3 Taking off a back cover 1 Pull out a switch cover after taking out screws 2 Pull out a back cover backwards and take it off It is possible to do test sewing by attaching a thread guide plate set ...

Page 7: ...d dog height is 0 89 1 09 mm from upper surface of a needle plate Adjustment 1 Under checking condition while pushing a feel lifting lever 1 against a pin 3 of a shuttle adjust lever 2 correct feed dog height by loosening 2 screws 4 and turning an adjusting nut 5 Lift a screw driver down Clockwise direction Feed dogs become high Lift a screw driver up Anticlockwise direction Feed dogs become low 0...

Page 8: ...le tip is the same level as bottom surface of a gage Bottom surface of a gage is 11 17mm from the centre of a shuttle Top surface of a gage is 11 47mm from the centre of shuttle Adjustment 1 Remove a face cover 2 Remove a thread guide plate set 3 Loosen a screw 2 of a needle bar clamp 1 and correct needle bar height by sliding it up and or down After adjustment tighten a screw 2 securely When tigh...

Page 9: ... 19 Original issue Jun 2012 Service Manual HZL 12Z Model 4 HOOK OF NEEDLE THREADER Checking and adjustment Adjust position of a hook by using one of accessories a small screw driver when a hook is not aligned ...

Page 10: ...edle plate by turning a hand wheel 3 Check if clearance between a presser foot and a needle plate is approx 5 5 mm Adjustment 1 Raise a presser foot lifter 2 Loosen a screw 2 of a presser bar bracket 1 and correct presser bar 3 height by sliding it up or down 3 After adjustment tighten a screw 2 securely keeping a presser foot in parallel with feed dog direction 5 5mm 1 2 ...

Page 11: ...needle to its lowest position 3 Check if a needle comes to align with dent mark at the left end of a needle plate eyehole at this needle position Adjustment 1 Remove a face cover 2 Remove a thread guide plate 3 Loosen a screw 3 connecting a zigzag guide bar 2 to a needle bar support 1 and correct needle position by moving the support 1 After adjustment tighten a screw 3 1 2 3 ...

Page 12: ...rt its leftward movement until it comes up 3 4mm above the upper surface of a needle plate Adjustment 1 Loosen 2 screws 2 of a worm gear 1 on an upper shaft 2 Holding a gear 1 turn a hand wheel and adjust set angle of a gear to the upper shaft Needle side motion too early Turn a hand wheel towards you Needle side motion too late Turn a hand wheel away from you During adjustment use only one screw ...

Page 13: ... a needle plate hole at the extreme front end position of feed dogs and clearance b between a rear edge of feed dogs and that of a needle plate eyehole at the rear end position of feed dogs are approximately the same It should be a b Adjustment 1 Turning hand wheel by hand bring feed dogs to their front end position 2 Loosen screw 3 setting a feed rocking arm 2 to a feed rocking shaft 1 and correc...

Page 14: ...int comes to align with left side of needle At this position check if a shuttle hook point is 1 0 1 5 mm above the upper edge of a needle eye A Adjustment 1 Loosen screws 1 of a shuttle adjust lever 2 and correct the timing by moving a lever 2 towards left or right while pressing a lever 2 against a shuttle drive arm 4 to ensure positive engagement of projection 3 on the back of a lever 2 with mat...

Page 15: ...sition until a shuttle hook point comes to align with left side of needle At this position check if clearance between a shuttle hook point and a needle plate eyehole is 0 0 1 mm Adjustment 1 Remove outer covers 2 Loosen screws 2 of a shuttle race set 1 and adjust the position Fix a gage and conform needle plate hole s position to a boss 3 Check if a boss of a gage goes up and down smoothly 4 Tight...

Page 16: ...re is no rattle in a shuttle shaft Adjustment 1 Loosen 2 screws 2 of a roller board 2 Adjust the engaging of a rack 4 and a shuttle shaft gear 5 by moving a roller 3 up and down 3 Make sure not to make an upper torque heavy by adjusting engaging 4 Tighten up 2 screws 2 after adjustment Make sure that there is no rattle in the directions as an arrow indicates 1 2 4 3 5 ...

Page 17: ... at the tension of a dial The tension of a bobbin case should be 22 28 g Check the balance of top thread and bobbin thread at zigzag sewing for test Adjustment 1 Remove a face cover 2 Keep the dial position in your mind 3 Adjust tension as prescribed by turning a DT pressure adjusting gnat Turn an adjusting gnat in clockwise direction Tension becomes stronger Turn an adjusting gnat in anticlockwis...

Page 18: ...12 Service Manual HZL 12Z Model 13 ADJUSTING MOTOR BELT TENSION Checking 1 Remove a face cover 2 When pushing between an upper shaft of a belt and a motor at 200 g loosen 2 gnats 1 as it bows 7mm 3 After adjustment tighten 2 gnats 1 1 ...

Page 19: ...odel Follow the following directions to change backward pitch though it is usually fixed 1 Adjust backward pitch by turning a screw 1 When not removing a face cover put in a screw driver from an eyehole of a face cover top and turn a screw 1 Turn it in clockwise direction Backward pitch becomes bigger Turn it in anticlockwise direction Backward pitch becomes smaller 2 Adjust backward pitch as foll...