Owner's Manual

CONTENTS
1. NAMES OF MAJOR PARTS................................. 1
2. MACHINE SPECIFICATIONS................................. 3
3. OPTIONAL PARTS .................................................. 5
4. WORK TABLE AND MOTOR................................ 7
5. INSTALLATION ........................................................ 9
5-1. Installing the oil pan ........................................... 10
5-2. Installing the machine head ............................... 11
5-3. Installing the knee lifter assembly ..................... 12
5-4. Installing the belt ................................................. 14
5-5. Installing the bobbin winder .............................. 14
5-6. Installing the belt cover ...................................... 15
5-7. Installing the pulley ring ..................................... 17
5-8. Installing the filter ............................................... 17
5-9. Lowering the suction tube.................................. 18
5-10. Installing the cotton stand ................................ 18
5-11. Ground Wire Connections (877A/878A) ........... 19
5-12. Lubrication.......................................................... 20
5-13. Checking the machine pulley rotating
direction .............................................................. 23
6. PREPARATION BEFORE SEWING ...................... 24
6-1. Installing the needle ............................................ 24
6-2. Removing the bobbin or cap ............................. 25
6-3. Winding the lower thread................................... 26
6-4. Installing the bobbin or cap ............................... 28
6-4-1. Installing the bobbin
[877A, 877B, 878A] ...................................... 29
6-4-2. Installing the cap
[878B, 877B (option)] ................................... 30
6-5. Threading the upper thread ............................... 31
6-6. Adjusting the stitch length ................................. 35
6-7. Keeping the presser foot in the raised
position ................................................................. 36
7. SEWING..................................................................... 37
7-1. Sewing.................................................................. 38
7-2. Backtacking........................................................... 38
8. THREAD TENSION.................................................. 39
8-1. Adjusting the thread tension.............................. 39
8-2. Adjusting the presser foot pressure .................. 43
8-3. Adjusting the trailing length after thread
trimming (877B, 878B) ........................................ 43
8-4. Adjusting the walking foot and inner presser
foot........................................................................ 45
9. CLEANING ................................................................ 47
10. STANDARD ADJUSTMENTS ............................... 50
10-1. Adjusting the thread tension spring .................. 51
10-2. Adjusting the presser foot height ...................... 55
10-3. Adjusting of the feed dog height ...................... 56
10-4. Adjusting the forward/back position of
the feed dog ........................................................ 57
10-5. Adjusting the needle and rotary hook timing .. 59
10-5-1. Needle to rotary hook point gap ............... 59
10-5-2. Clearances between rotary hooks
and needle plate .......................................... 61
10-5-3. Clearance between rotary hook and
opener........................................................... 62
10-5-4. Needle bar height and lift amount ............ 63
10-5-5. Adjusting the walking foot, inner
presser foot and needle timing.................. 66
10-6. Tension Release (877B, 878B) ............................ 67
10-7. Synchronizer adjustment (877B, 878B) ............. 69
10-8. Upper and lower shaft timing adjustment ....... 71
10-9. Adjusting the rotary hook lubrication
amount ................................................................. 73
10-10. Changing the knee lifter heaviness ................. 75
11. REPLACING THE FIXED KNIFE AND
MOVABLE KNIFE (877B/878B)
............................ 76
12. REPLACING GAUGE PARTS (CHANGING THE
NEEDLE WIDTH-878A/878B)
................................ 83
13. INSTALLING OPTIONAL PARTS ......................... 90
13-1. Replacing the rotary hook.................................. 91
13-2. Replacing the upper thread tension
assembly (878A/878A) ......................................... 95
14. SAFETY EQUIPMENT............................................. 96
15. TROUBLESHOOTING GUIDE ............................. 100
SU-877A/B, TU-878A/B (English)