SINGER 321D-241M-24 INDUSTRIAL SERGER - Manual (Page 22)

Troubleshooting
19 Ultra High Speed Overedge and Safety Stitch Machine | Instruction Manual and Parts List
Problems Possible Causes Possible Solutions
Uneven Stitches
1. Wrong threading. 1. Threading correctly.
2. Wrong installation of thread stand. 2. Install thread support correctly.
3. Wrong setting of lower knfe. 3. Adjust lower knife correctly.
4. Knives does not cut perfectly. 4. Adjust or replace knives.
5. Thread guide or tension disc with burrs. 5. Replace the part.
6. Needle point damaged. 6. Replace the needle.
7. Inadequate height of feed dog. 7. Adjust the height of feed dog.
8. Inadequate thread tension. 8. Adjust thread tension.
Puckering
1. Thread tension is too strong. 1. Adjust thread tension.
2. Inadequate pressure on presser foot. 2. Adjust pressure on presser foot.
3. Inadequate height of feed dog. 3. Adjust the height of feed dog.
4. Knives does not cut perfectly. 4. Adjust or replace knives.
5. Differential feed is not correct. 5. Adjust differential feed ratio.
6. Needle is too thick. 6. Use proper needle to cloth and thread.
Poor
chain-off stitches
1. Incorrect presser foot. 1. Adjust presser foot correctly.
2. Inadequate synchronism of lopper cam. 2. Adjust looper cam.
3. Chain stitch looper installed wrongly. 3. Adjust looper correctly.
4. Wrong passage of thread. 4. Pass thread correctly.
5. Thread tension inadequate. 5. Adjust thread tension.
6. Wrong relation of needle with looper. 6. Adjust relation of needle with looper.
7. Needle plate or presser foot with burr. 7. Replace the part.
8. Rough thread tension disc. 8. Polish thread tension disc.