Brother DB2-B721 - English; Table of Contents

CONTENTS
1. NAMES OF MAJOR PARTS 1
2. MACHINE SPECIFICATIONS 3
3. OPTIONAL PARTS (B722/B724) 5
4. WORK TABLE 7
5. MOTOR (B721/B723) 8
6. INSTALLATION 9
6-1. Installing the oil pan 10
6-2. Installing the machine head 11
6-3. Installing the knee lifter assembly
(Except -SOD) 12
6-4. Installing the belt 13
6-5.
Installing the bobbin winder 14
6-6.
Installing the belt cover 15
6-7.
Installing the cotton stand 18
6-8. Ground Wire Connections
{B721/B723) 18
6-9. Lubrication 19
6-10. Checking the machine pulley
rotating direction 20
7. PREPARATION BEFORE SEWING 21
7-1. Installing the needle 21
7-2.
Removing the bobbin case 22
7-3. Winding the lower thread 23
7-4. Installing the bobbin case 25
7-5. Threading the upper thread 26
7-6. Adjusting the stitch length 27
7-7. Using the thread wiper
{B722/B724-40Q 90D option) 28
8. SEWING 29
8-1. Sewing 30
8-2. Backtacking 30
9. THREAD TENSION 31
9-1. Adjusting the thread tension 31
9-2. Adjusting the presser foot
pressure 32
9-3. Adjusting the trailing length after
thread trimming (B722/B724) 32
10.CLEANIN G 35
11.STANDARD ADJUSTMENTS 39
11-1. Adjusting the thread tension
spring 40
11-2. Adjusting arm thread guide R 42
11-3.
Adjusting the presser foot height 43
11-4.
Adjusting the feed dog height 44
11-5. Adjusting the feed dog angle 45
11-6.
Adjusting the needle bar height 46
11-7. Adjusting the needle and feed
mechanism timing 47
11-8.
Adjusting the needle and rotary
hook timing 49
11-9. Checking the rotary hook and B-case
holder position bracket clearance 50
11-10.Adjusting the upper shaft and
rotary hook lubrication amount 51
11-11.Adjusting the synchronizer
(B722/B724) 52
12.REPLACING THE FIXED KNIFE AND
MOVABLE KNIFE (B722/B724) 54
12-1. Replacing the fixed knife 54
12-2. Replacing the movable knife 55
13.TROUBLESHOOTIN G 56
DB2-B720 series (English)