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TABLE OF CONTENTS

 0. Dismantling  the  rear  cover 

 1. Upper  shaft  end  play 

 2. Cam  stack  gear  mesh 

 3. Needle  bar  height 

 4. Shuttle  timing 

 5. Needle  position 

 6. Zeroing  the  needle 

 7. Feed  dog  height 

 8. Feed  lifting  cam 

 9. Stretch  stitch  selector  cam 

10. V  belt  adjusting 

11. Bobbin  winder 

12. Take-up spring replacement and setting  

13. Bobbin  case tension 

14. Stretch  stitch  sewing 

15. BH  balance

16. Electrical connections  

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Summary of Contents for Magnolia 7312

Page 1: ...SERVICE MANUAL MODEL 7312 ...

Page 2: ...ing 5 Needle position 6 Zeroing the needle 7 Feed dog height 8 Feed lifting cam 9 Stretch stitch selector cam 10 V belt adjusting 11 Bobbin winder 12 Take up spring replacement and setting 13 Bobbin case tension 14 Stretch stitch sewing 15 BH balance 16 Electrical connections PAGE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 17 ...

Page 3: ...ING THE REAR COVER 1 Unscrew the screws a b c d e f 2 Open face cover and shuttle cover and pull out the spool pins 3 Remove the rear cover in direction of arrow a b e f c d spool pins face cover shuttle cover 1 ...

Page 4: ...uring the revolution Adjustment 1 Remove rear cover 2 Loosen set screw C Hexagen M5x5 in collor 3 Plate screwdriver blade E between stop clamp motion and casting body 4 Hold collor B to left touch with slide front spherical bearing of upper shaft A then tighten set screw C 5 Take out screwdriver E 6 Recheck for end play ALL MODELS 2 A B C D E Front spherical bearing Stop clamp motion ...

Page 5: ... Check at three different points in a full revolution zero or very slight play is acceptable Adjustment 1 Loosen set screw E 2 Hold gear F slightly forward but can not turn 3 If machine marked bind must be remove backward 4 Tighten set screw E 5 Recheck pendulum timing ALL MODELS 3 F E ...

Page 6: ...ition 4 Then slowly raise needle bar to a position the distance shall be 1 mm Adjustment 1 Open face cover 2 Loosen needle bar clamp screw A 3 Slightly move needle bar B up or down until location is 1 mm 4 Tighten clamp screw Torque 15kg cm Attention 1 After completing adjustment make sure that needle is parallel to shuttle ALL MODELS A B L R 1 mm shuttle hook 4 a ...

Page 7: ...n in the left needle position 4 The point of shuttle shall be 3 2 mm to the left of needle Adjustment 1 Remove rear cover 2 Loosen 2 screw A on driver gear 3 Slightly turn driver gear B clockwise to decrease clearance and counter clockwise to increase clearance 4 Tighten both screw A and recheck ALL MODELS C A B 3 2 mm Shuttle hook 5 Lower shaft a ...

Page 8: ...ht entry should be equal distance from the edge of the needle plate hole A Adjustment 1 Open face cover 2 Loosen set screw D and B 3 Turn eccentric C as A shown correct needle location 4 Tighten set screw B and D 5 Check distance must be 0 4 mm between needle bar and stopper plate at the left or right position ALL MODELS A 5 mm D B C 0 4 mm 6 ...

Page 9: ...aight stitch 3 Shall be no or minimul movement below 0 3 mm Adjustment 1 Remove rear cover 2 Select straight stitch position 3 Loosen screw or nut A 4 Remove connecting plate B so that no or minimul movement of needle bar 5 Tighten screw or nut A ALL MODELS A B B A C Model Model 7 ...

Page 10: ... The top or the feed dog should be 0 8 1 0 mm above the surface of the needle plate Adjustment 1 Remove rear cover 2 Bring feed dog to it s highest point 3 Loosen nut A 4 Turn set screw B as required 5 Tighten nut A ALL MODELS 0 8 1 0 mm Feed dog Needle plate 8 A B ...

Page 11: ...ime teeth of feed dog are required to keep same height with that of needle plate surface Adjustment 1 Remove rear cover 2 Loosen feed lifting cam set screw Hexagon M5x5 A 3 Turn feed lifting cam B up to same height of feed dog teeth and needle plate surface As F 2 shown 4 Tighten set screw A ALL MODELS A B FIG 2 9 ...

Page 12: ...d D stitch length must be same Adjustment 1 Remove rear cover 2 Set pattern select dial at A position 3 Loosen two set screw Hexagon M4x4 E and F 4 Turn SS selector cam G up to distance above 1 mm of pin H and SS selector cam end 5 Then tighten E F two set screw MODEL JANOME 7312 E F H G E F G H A B C D 1 0 mm 10 D C B A ...

Page 13: ...out parallel of two side during pressure 300g use spring gauge measured Adjustment 1 Remove rear cover and front cover 2 Loosen two screw of motor B 3 Movement motor up and down adjusting belt tension until as required 4 Tighten two nuts ALL MODELS B C A 300g Motor belt 11 ...

Page 14: ... Replace clamp stop motion large screw A and tighten screw B 5 Recheck for proper operation Bobbin winder Check 1 Wind a bobbin and check if thread is wound evenly F or forms a cone at eigther end G or H 2 The bobbin winder should stop turning when the thread is wound to within 0 8mm 1 5mm from the outer rim of the bobbin Adjustment 1 Loosen screw J 2 If bobbin is wound unevenly as in G move threa...

Page 15: ...K I A D C L J 0 8 1 5mm F G H 11 B E 13 ...

Page 16: ...p spring should be 1 1 5 mm B 3 When this spring in operation Lift in arrow direction tension be 6g 12g Adjustment 1 Loosen set screw C 2 Turn the spring D In clockwise to increase tension In counter clockwise to decrease tension Adjust until this spring tension reaches 6g 12g 3 Tighten set screw C 6g 12g D C B 1 1 5 m m A C 14 ALL MODELS ...

Page 17: ...lly 3 Remove shuttle race cap 4 Tie race cap to thread from bobbin case 5 Hold bobbin case upside down without touching tension spring 6 Loosen tension spring adjustment screw L until weight of race cap stars pulling thread from bobbin case 7 Gradually tighten screw L until bobbin stops turning L ALL MODELS 15 ...

Page 18: ...ust be counter clockwise turn until nice pattern can be sewn out like b 5 Tighten 2 nuts F G 15 BH BALANCE Check 1 Sew a buttonhole 2 Check that both legs of the buttonhole have equal stitch density Adjustment 1 Remove rear cover 2 Placement machine in step 3 of buttonhole 3 Loosen 6mm nut B 4 Turn adjustment screw A clockwise to increase stitch length on right leg Counter clockwise to shorter sti...

Page 19: ...16 ELECTRICAL CONNECTIONS 17 Switch Light Motor 120V FDM TYPE 230V FDM TYPE Cap Motor ...

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