JUKI MB-377 - Page 32

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CONTENTS
1. SPECIFICATIONS........................................................................................................... 1
2. STANDARD ADJUSTMENT ...........................................................................................2
(1) Height of the needle bar .....................................................................................................................2
(2) Positioning the needle and the looper ..............................................................................................2
(3) Timing the travel of the yoke slide ....................................................................................................4
(4) Positioning the cloth feed cam..........................................................................................................6
(5) The floating timing of the tension disc No. 2 ...................................................................................6
(6) Lift and pressure of the button clamp ..............................................................................................8
(7) Thread tension disc No.1 ...................................................................................................................8
(8) Positioning the thread nipper ..........................................................................................................10
(9) Positioning the stitch adjusting cam ..............................................................................................10
(10) Positioning the stop motion disc and the stop motion plunger...................................................12
(11) Pressure of the button clamp ..........................................................................................................12
(12) Positioning the button clamp lifting link ........................................................................................12
(13) Positioning the needle driving pulley pressure applying lever....................................................14
(14) Positioning the thread pull-off lever ...............................................................................................14
3. ADJUSTMENT OF AUTOMATIC THREAD TRIMMER ................................................16
(1) The mechanism and the name of each component of the thread trimmer .................................16
(2) Clearance between the button clamp lifting lever and the adjusting screw ...............................16
(3) Adjusting the position of the moving knife ....................................................................................18
(4) Adjusting the height of the thread separating claw of the moving knife ....................................18
(5) Installing the button clamp lifting rod.............................................................................................18
4. ADJUSTMENT OF KNOT-TYING MECHANISM (EXCLUSIVE FOR MB-377)............20
(1) The mechanism and the name of each component of the knot-tying ......................................... 20
(2) Positioning the knot-tying arm stopper..........................................................................................20
(3) Positioning the knot-tying notch .....................................................................................................22
(4) Adjusting the thread bind plate (Exclusive for MB-377) ...............................................................22
(5) Adjusting the tension lever (Exclusive for MB-377) ......................................................................24
(6) Adjusting the speed slowing friction plate (MB-377) ....................................................................24
5. CORRECTIVE MEASURES FOR STITCHING TROUBLES ........................................26
(1) Thread breakage ...............................................................................................................................26
(2) Thread remaining and/or poor tightness of stitches .....................................................................26
(3) Skip of stitches .................................................................................................................................27
(4) Thread slippage from the needle.....................................................................................................27
(5) Excessive remaining thread ............................................................................................................27
6. CORRECTIVE MEASURES FOR MECHANICAL FAILURES .....................................28
(1) Defective stop motion ......................................................................................................................28
(2) The button clamp does not go up. ..................................................................................................28
(3) The clutch of the needle driving pulley slips. ................................................................................28
(4) The needle driving pulley is overheated, and the starting pedal does not work smoothly. ......28
7. THREAD TRIMMING TROUBLES AND THE CORRECTIVE MEASURES .................29
8. CAUSES OF TROUBLES AND THE CORRECTIVE MEASURES FOR MB-377........30