Reasons

Solutions

1. Needle shafts’ locating part is too low

Loosen screw and turn main shaft to 0 degree, then adjust it

2. Driving slide doesn’t spring back

Check whether the machinery is jammed or the spring doesn’t work

Reasons

Solutions

1. Needle shafts’ locating part is too high

Loosen screw and turn main shaft to 0 degree, then adjust it

Reasons

Solutions

1. Bad quality of thread

Replace it

2. Needle shaft is too high

Adjust its height at 196 degree

3. Thread track is not smooth

Check and polish the track

Reasons

1. Thread-scissoring position changes

A. Moving knife and Thread-scissoring shaft get loose

Adjust and fasten

B. Thread-scissoring part changes position

Adjust

C. Electromagnet changes position, cam ring is too low

Adjust

D. Moving knife’s position of opening and shutting is low

Adjust

2. Not scissoring thread

A. Moving knife and unmoving knife cooperate poorly

Adjust the angle of the unmoving knife

B. Moving knife changes position of opening and shutting

Adjust the position of 293 degree +/- 2 degree

C. Knives go blunt

Replace them

D. Moving knife changes position

Adjust

E. Spring loop of bottom thread clip deforms

Replace it

3. Thread scissored is too short

A. Tension of lower thread changes

Adjust

B. Shuttle shell deforms

Replace

C. Bottom thread clip changes position

Adjust

D. Bottom thread clip deforms

Replace

E. Computer setup is wrong

Modify into long thread scissoring

4. Electric appliance reasons

Refer to book of direction

Reasons

Solutions

1. Upper thread is not cut, or too short

A. Thread-cutting knife changes position

Adjust the position of moving knife

B. Holding part changes position

Adjust the angle

2. Drawing thread is not at the right position

A. Upper drawing thread part was locked

Open the lock

B. Thread-drawing hook changes position, or the thread drawn is not to place

Adjust the hook

C. Thread-picking part is loose

Adjust and fasten

D. Thread-drawing electromagnet doesn’t work

Replace it

Reasons

Solutions

1. Needle problem

A. Bad quality of the needle

Replace the needle

B. Needle is not properly installed

Reinstall it

C. Needle is not straight, or not in the position

Reinstall and adjust

D. Something is on the needle point

Remove it

E. Fixing screw of the needle is not in the right position

Adjust it to 30 degree to the right

2. Thread problem

A. Bad quality of the thread

Replace the thread

B. Thread doesn’t match with the needle

Adjust the tension of thread

C. Tension of upper thread and lower thread is too strong

Replace

D. Too many branches of the upper thread

Replace it

E. Thread is off the track

Repair the track

3. Thread track is not smooth

A. Burr in the needle board hole

Polish or replace

B. Burr in the needle track hole

Polish or replace

C. Burr on the spinning wheel disk

Replace it

4. Spinning shuttle

A. Scratch on the shuttle

Polish or replace

B. Scratch on the shuttle shell

Polish or replace

C. Shuttle and shell deform

Replace them

D. Scratch on the locating shaft

Polish or replace

E. Bad lubrication

Add lube

5. Parameter is changed

Adjust the parameter

6. Designs are too dense, or needle is not long enough

Repair the board