Table of contents
2 Service Instructions 670/680 - 03.0 - 02/2020
9.7 Differential feed .......................................................................... 50
9.7.1 Setting the differential feed......................................................... 51
9.7.2 Setting the synchronization of top and bottom feed ................... 52
10 Position of the hook and needle ............................................. 53
10.1 Setting the loop stroke................................................................ 53
10.2 Setting the needle bar height...................................................... 54
10.3 Setting the hook side clearance ................................................. 55
10.4 Setting the needle guard ............................................................ 56
11 Setting the bobbin case lifter .................................................. 57
11.1 Setting the lifting gap .................................................................. 57
11.2 Setting the timing for opening..................................................... 58
12 Sewing feet................................................................................ 59
12.1 Setting the initial position of the lifting gear ................................ 60
12.2 Setting an even sewing foot stroke............................................. 61
12.3 Setting the stroke movement for the feeding foot....................... 62
12.4 Setting the sewing foot pressure ................................................ 63
12.5 Setting the sewing foot lifting height ........................................... 64
12.5.1 Setting the mechanical sewing foot lifting................................... 64
12.5.2 Setting the sewing foot lifting height ........................................... 66
13 Setting the needle thread tension........................................... 68
14 Winder ....................................................................................... 70
14.1 Setting the winder....................................................................... 70
14.2 Setting the hook thread guide..................................................... 73
15 Thread cutter............................................................................. 74
15.1 Setting the height of the thread-pulling knife .............................. 75
15.2 Setting the cutoff curve............................................................... 76
15.3 Setting the swivel range of the thread-pulling knife .................... 77
15.4 Setting the cutting pressure........................................................ 78
15.5 Setting the hook thread clamp.................................................... 79
15.6 Setting point in time for cutting ................................................... 80
16 Setting the potentiometer ........................................................ 81
17 Edge cutter (only 680) .............................................................. 83
17.1 Assembling and setting the blade............................................... 84
17.1.1 Assembling the counter blade .................................................... 84
17.1.2 Assembling and setting the movable blade ................................ 84
17.1.3 Setting the cutting angle ............................................................. 86
17.1.4 Setting the cutting pressure and blade position.......................... 87
17.2 Setting the timing of the blade stroke movement ....................... 88
17.3 Setting the stroke height of the blade ......................................... 89
18 Stitch loosening unit ................................................................ 90
18.1 Setting the swivel movement timing ........................................... 91
18.2 Setting the position of the swivel movement .............................. 93
18.3 Setting the material thickness scanner for the stitch loosening
unit.............................................................................................. 95
18.4 Setting the height of the stitch loosening finger.......................... 97