Pfaff 1520 - Manual

6 Specifications of PFAFF machines PFAFF 1540 Electronic free-arm utility stitch machine with 40 sewing programs (push buttons). A straight stitch program with 15 needle positions. A zigzag program with 15 needle positions. A buttonhole program with adjustable width. 37 utility stitches. High-ohm fo...

8 Removing the housing covers Note: Before adjusting or repairing the machine, make sure to remove the housing covers as described in this manual. z Disconnect the machine's main plug. z Remove needle and presser foot. z Remove detachable work support. z Remove top cover. z Switch on bobbin winder. ...

9 z Loosen the fastening screws 4, 5, 6 and 7 of the rear housing shell (fig. 3 and 4). z Loosen the snap connections by pressing with your thumb on the spots marked with arrows on the inner surface of the arm (fig. 5). z Remove the rear housing shell. z Remove motor cover.

10 z Loosen the fastening screws 8, 9, and 10 of the front housing shell (fig. 5 and 6). z Remove fastening screws 10 and 11.

11 z Remove fastening screw 12 (fig. 7). z Switch on the top key row of the utility stitch unit. z Carefully remove the front housing shell by lifting it off. The assembly must be carried out in reverse order.

13 Feeding system 1. Adjustment of the toothed belt tension Requirement: The toothed belt must be so taut that the sewing hook has no play in its direction of rotation. However, it must be possible to turn the machine easily. Adjustment: z Loosen screw 1 (fig. 1) z Re-position tensioning roller 2 wi...

14 2. Adjustment of feed dog in sideways direction on Pfaff 1520 Requirement: The left and right clearance of the feed dog in the feed slot must be the same (fig. 2). Check: Carry out a visual check of the feed dog position. Adjustment: z Loosen the two screws 3 and 4 (fig. 2a). z Loosen screw 5. z ...

16 3. Adjustment of feed dog in sideways direction on Pfaff 1530-1540 Requirement: The left and right clearance of the feed dog in the feed slot must be the same (fig. 3). Check: Carry out a visual check of the feed dog position. Adjustment: z Lay the machine on its back. z Loosen screw 12 (fig. 4)....

18 4. Adjustment of feed dog height Requirement: At the highest working position of the feed dog, the tips of the feed dog teeth must protrude above the needle plate surface by 0.9 mm (fig. 6). Check: z Remove the needle. z Remove the presser foot. z Set the maximum stitch length. z Place bridge gau...

19 5. Adjustment of presser bar height on Pfaff 1520 Requirement: With the presser bar lifter raised, there must be a clearance of 8 mm between the needle plate and the bottom of the zigzag foot. Check: z Raise the presser bar lifter. z Fit the zigzag foot. z Lower the feed dog. z Fully raise the pr...

22 7. Adjustment of top feed foot in sewing direction Requirement: The front edge of the top feed foot must be between the first and second tooth point of the center tooth row of the feed dog (fig. 11). Check: z Raise the presser bar lifter. z Remove presser foot & presser foot holder. z Set the...

25 z Set guide piece 31 at a clearance of 0.2 mm from cross head 32 (fig. 14). z Tighten screw 25. Cross-check: z Turn the handwheel and check for clearance of 0.2 mm.

27 10. Adjustment of feed regulator cranks on Pfaff 1540 Requirement: The feed regulator cranks must not have any axial play. Check: Move the feed regulator cranks laterally backwards and forwards (fig. 16). Adjustment: z Loosen the two screws 5 and 36. z Push feeding eccentric 33 to the right again...

28 11. Zero point adjustment of stitch length regulator Requirement: When the stitch length graduated dial is set to "0", the feed dog should only move up and down. Check: z Set the stitch length graduated dial to "0". z Place a piece of fabric under the presser foot. z Lower the pre...

30 12. Timing of feed motion Operating sequence: When the rising needle has cleared the fabric, the feed dog moves up above the needle plate. The risen feed dog pushes the fabric to the rear. Shortly before the end of the feeding motion, the take-up lever is in its highest position (t.d.c). At a sti...

32 Automatic utility-stitch unit 13. Replacing the automatic module on Pfaff 1520 - 1530 Removal: z Disconnect the machine's mains plug. z Remove the housing covers as described in this manual. z Disconnect light plug 46 (fig. 22). z Detach spring 47 at the top of the push-lever. z Loosen screw 48. ...

34 14. Adjustment of the locking disk Note: Carry out this adjustment only if compelling reasons exist. For this adjustment the automatic module has to be removed. Requirement: When the automatic module is switched off, lifting pin 66 should be exactly centered in the groove (fig. 24). Check: z Set ...

37 17. Adjustment of needle penetration in needle plate slot Requirement: At straight stitch setting with needle position "center" the needle must be exactly in the center of the needle plate slot (fig. 30). Check: z Remove presser foot. z Insert a new needle. z Set stitch width adjustment d...

38 18. Adjustment of the sideways movement of the needle bar Requirement: During zigzag sewing operation the sideways movement of the needle should stop above the highest possible fabric thickness. The sideways movement of the needle must start when the needle point is leaving the needle plate. It m...

40 19. Adjustment of the stop for the left needle position Requirement: At the widest zigzag stitch setting the crank should rest on the stop. Check: z Set stitch width adjustment dial to "5". z Set needle position adjustment dial to "center". z Set the adjustment dial on the automat...

42 20. Adjustment of the feed reversing bar Requirement: At straight stitch or stretch stitch setting there must be a clearance of 0.2 mm between reversing bar 54 and the end of the lever of feeler 91 (fig. 39). Check: z Set the adjustment dial for the automatic unit to "E". z Move the stitc...

44 21. Replacing the utility-stitch unit on Pfaff 1540 Removal: z Loosen screw 5 (fig. 42). z Remove circlip 14. z Remove bolt 11. z Remove circlip 92. z Disconnect pull rod 93. z Detach feed regulator cranks together with connecting rod 10 to the left. z Loosen the three screws 94, 95 and 96. z Rem...

46 22. Adjustment of the gears in relation to each other Requirement: The two gears must not have any play, must not bind, and must be parallel to each other. Check: z Check for free running by turning the handwheel, check for lack of play by turning the gears back and forth and carry out a visual c...

47 23. Replacing the zigzag-stitch unit on Pfaff 1540 Removal: z Disconnect the machine's mains plug. z Remove the housing covers as described in this manual. z Set stitch width adjustment dial 70 to "0" (fig. 44). z Remove circlip 71 from connecting rod 72. z Remove circlip 92 (fig. 46). z ...

54 Stitch forming parts (sewing hook) Foreword: The sewing hook adjustment consists basically of the three following adjustments: z Needle rise (sewing hook timing) z Needle bar height z Hook-to-needle clearance Needle rise (sewing hook timing): The needle rise is the movement by which the needle mu...

57 Cross-check z Carry out a visual check at straight and zigzag stitch settings.

59 30a. Adjustment of bevel gears Requirement: The bevel gears must move easily and without play. Adjustment: z Push bevel gear with lifting eccentric to the left until it rests on bevel gear 38 without play. z Tighten screw 37 on the surface of the drive shaft. Check: z As described under "Requ...

60 31. Sewing hook timing Requirement: When the needle bar has moved 2.2 mm upwards from its lowest position, with the machine set for straight stitch and center needle position, the sewing hook point must be exactly behind the center line of the needle (fig. 62). Check: z Remove presser foot and ne...

62 32. Adjustment of needle bar height This machine has a transverse double-rotating hook. At the right zigzag penetration, the sewing hook reaches the needle a little earlier and at the left penetrati- on a little later than at the center penetration. As a result of this, the position of sewing hoo...

63 33. Adjustment of bobbin case position finger Requirement: The clearance between the position finger and the bottom of the groove in the bobbin case base must be 0.7 mm. Check: z It must be possible to insert clearance gauge (00-880133-01) with ease but without play between the position finger an...

64 Stitching off 34. Adjustment of needle threader Requirement: With the threader lever pushed fully down, prong 115 must pass through in the center between the top and bottom edge of the needle eye of a size 70 needle (fig. 69). The prong must have the same distance to either side of the walls of t...

66 35. Adjustment of bobbin winder stop Requirement: The bobbin winder must stop when the thread has reached a level of 1 mm below the bobbin rim. Check: z Wind a bobbin and check that the winder stops as required. Adjustment: z Loosen screw 123 (fig. 72). z Position stop 124 to the left for less th...

67 36. Adjustment of bobbin thread tension Requirement: The force required for pulling cotton thread 50/2 or synthetic fiber thread 100/3 off the bobbin must be approximately 20-25 g. Check: z When a threaded bobbin case hangs on its thread, it must not slide downwards by its own weight. z Upon shar...

68 37. Adjustment of needle thread tension Requirement: Within the adjusting range from 3 to 5, the interlacing of needle thread and bobbin thread (cotton thread 50/2 or synthetic fiber thread 100/35) must take place approximately in the middle of the fabric (fig. 74). Check: z Set needle thread ten...

70 38. Adjustment of thread check spring stroke The thread check spring prevents the descending needle from piercing the slack needle thread. The needle thread is slackened by the descending take-up lever. Requirement: Thread check spring 126 must keep the needle thread taut at least until the needl...

72 39. Adjustment of equal stitch length for left and right buttonhole seams Requirement: The stitch lengths of the left buttonhole seam and of the right buttonhole seam must be the same (fig. 78). Note: When the correct zero point has been set on the stitch length regulator, the stitch lengths of t...

75 Repair Instructions 42. Removing and fitting the needle thread tension Removal: z Remove the needle thread tension. z Press the two plastic noses 131 together and remove tension dial 132 (fig. 93). z Remove spring disk 133. z Turn knurled nut 125 out of guide 134. z Remove guide 134. z Remove knu...

76 43. Changing the pressure spring in the handwheel release Removing the handwheel release z Remove plastic cap 141 using clearance gauge 00-880 133-01 (fig. 94). z Remove metal screw 142. z Pull out handwheel release disk 143 and take out pawl 144, clutch piece 145 and pressure spring 146. Fitting...

80 46. Changing the toothed belt Removal: z Disconnect the machine lead cord. z Remove needle and presser foot. z Remove detachable work support. z Remove top cover. z Switch on bobbin winder. z Remove the two Torx screws of the housing insert. z Remove the housing insert. z Remove the four retainin...

82 47. Adjusting the arm shaft crank z Press the straight stitch button. z Carefully loosen screw 152 on arm shaft crank 153 just enough to allow the arm shaft crank to be tur- ned on its shaft (fig. 107). z Raise the needle bar and insert the needle. z Firmly hold arm shaft crank 153 using the left...

84 48. Changing the bevel gears Note: Always change bevel gears in pairs. Removal: z Remove the housing covers as described in this manual. z Remove the synchronizer from the shaft to the right. z Loosen the two screws 101 on small gear 97 (fig. 110). z Remove small gear 97 from the hook driving sha...

88 49. Changing the motor Note: The motor must be replaced as a complete unit. Removal: z Disconnect the machine lead cord z Remove the detachable work support. z Remove the housing covers as described in this manual. z Remove the right-hand motor retaining screw 57 (fig. 113). z Disconnect light pl...

91 51. Changing the carbon brushes on motor types UUS 390 and UUS 393 Removal: z Remove the motor in accordance with point 49of this manual. z Slightly raise the two locking tabs 163 and remove cover 162 (fig. 115). z Unscrew the two groove nuts 170. z Pull the motor apart and remove end shield 171....

92 52. Changing the motor pinion Note: The motor pinion must only be removed when a rotor is exchanged. Removal: z Remove the motor in accordance with point 49 of this manual. z Insert two screwdrivers of the same width between pinion 58 and the motor bearing (fig. 116). z Rotate the two screwdriver...

93 53. Changing the motor toothed belt Removal: z Disconnect the machine lead cord z Remove the housing covers as described in this manual. z Remove the two screws 56 and 57 of the motor (fig. 117). z Disengage the handwheel. z Remove plastic cap 141. z Remove handwheel screw 142 (fig. 118). z Remov...

94 54. Changing the circuit board in foot control AE 010 Removal: z Turn the foot control so that it is resting on pedal 175. z Insert a screwdriver with a wide blade on the side opposite to the cables (fig. 119). z Turn the screwdriver while removing pedal 175 upwards. z Carefully remove cables 177...

95 55. Changing the mains connections in foot control AE 010 Note: When changing connections it is compulsory to use original PFAFF connection cables, as only these are approved. Removal: z Turn the foot control so that it is resting on pedal 175. z Insert a screwdriver with a wide blade on the side...

96 Safety test 56. Electrical safety test According to the German law on safe machine operation of June 24, 1986, VDE regulations are the reco- gnized rules in the field of electrical engineering and form the basis for electrical safety tests of technical appliances. The required electrical tests fo...

97 IV Simulated leakage current test: Milliampere = mA z Leave sewing machine plug in tester connection. z Use clamp to attach test lead of testing appliance M 5013 to presser bar. z Set testing range switch at "20 mA" (fig. 124). z Meter reading: 0.50 mA maximum.