DB2-B727, B728 (English)
CONTENTS
1. NAMES OF MAJOR PARTS
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0
1
2. MACHINE SPECIFICATIONS
.....................
0
2
3. WORK TABLE AND MOTOR
....................
0
3
3-1.
Work Table ............................................ 3
3-2.
Motor (B727) ......................................... 4
4. OPTIONAL PARTS
.......................................
0
5
5. INSTALLATION
.............................................
0
6
5-1.
Installing the oil pan ............................ 7
5-2.
Installing the machine head ............... 7
5-3.
Installing the knee lifter assembly ..... 8
5-4.
Adjusting the knee lifter ...................... 9
5-5.
Installing the belt ................................. 10
5-6.
Installing the bobbin winder ............... 10
5-7.
Installing the belt cover ....................... 11
5-8.
Installing the cotton stand .................. 14
5-9.
Ground Wire Connections (B727) ...... 14
5-10. Lubrication ............................................ 15
5-11. Checking the machine pulley
rotating direction .................................. 16
5-12. Test operation ....................................... 17
6. PREPARATION BEFORE SEWING
........... 18
6-1.
Installing the needle ............................ 18
6-2.
Removing the bobbin case ................. 19
6-3.
Winding the lower thread ................... 20
6-4.
Threading the lower thread ................ 22
6-5.
Threading the upper thread ................ 23
6-6.
Adjusting the stitch length .................. 24
7. SEWING
......................................................... 25
7-1.
Sewing .................................................. 26
7-2.
Backtacking ........................................... 26
8. THREAD TENSION
...................................... 27
8-1.
Adjusting the thread tension .............. 27
8-2.
Adjusting the presser foot pressure .. 29
8-3.
Adjusting the trailing length
after thread trimming (B728) .............. 30
9. STANDARD ADJUSTMENTS
................... 31
9-1.
Adjusting the presser foot height ...... 32
9-2.
Adjusting the feed dog height and angle 33
9-3.
Adjusting the needle bar height ......... 35
9-4.
Adjusting the needle and feed
mechanism timing ............................... 36
9-5.
Adjusting the needle and rotary
hook timing ........................................... 38
9-6.
Adjusting the thread tension spring .. 39
9-7.
Adjusting arm thread guide R ............ 41
9-8.
Adjusting the difference between the
forward and backtack stitch lengths ........ 42
9-9.
Adjusting the tension release timing ....... 43
9-10. Adjusting the walking foot
and presser foot ................................... 44
9-11. Adjusting the rotary hook
lubrication amount ............................... 47
9-12. Adjusting the oil pump ....................... 47
9-13. Adjusting the synchronizer (B728) ..... 48
10. REPLACING THE FIXED KNIFE
AND MOVABLE KNIFE (B728)
................ 50
10-1. Replacing the fixed knife ..................... 50
10-2. Replacing the movable knife ............... 51
11. CLEANING
................................................... 52
12. TROUBLESHOOTING
................................ 56
13. GAUGE PARTS
........................................... 72