WHAT TO DO WHEN
CONDITION
CAUSE
HOW TO FIX
REFERENCE
3. BREAKING
UPPER
THREAD
1. INITIAL SEWING SPEED IS
TOO FAST.
2. THREAD PATH IS
INCORRECT.
3. NEEDLE IS BENT OR
DULL.
4. UPPER THREAD TENSION
IS TOO STRONG.
5. NEEDLE SIZE IS
INAPPROPRIATE FOR
FABRIC.
6. NEEDLE EYE IS WORN.
7. NEEDLE HOLE IN NEEDLE
PLATE IS WORN OR
BURRED.
START WITH MEDIUM SPEED.
USE THE PROPER THREAD
PATH.
REPLACE WITH A NEW NEEDLE.
ADJUST UPPER THREAD
TENSION CORRECTLY.
USE APPROPRIATE NEEDLE
FOR FABRIC AND THREAD IN
USE.
CHANGE THE NEEDLE.
REPAIR THE HOLE OR REPLACE
THE NEEDLE PLATE.
P.7
4. BREAKNG
BOBBIN
THREAD
1. INCORRECTLY
THREADED BOBBIN
CASE.
2. TOO MUCH THREAD IS
AROUND IN THE BOBBIN.
3. LINT IS STUCK INSIDE
THE BOBBIN HOLDER.
4. THREAD QUALITY IS TOO
LOW.
5. THREAD IS JAMMING
AROUNG THE BOBBIN.
6. BOBBIN THREAD
TENSION IS TOO
STRONG.
THREAD BOBBIN CASE
CORRECTLY.
ADJUST THE POSITION OF
STOPPER.
CLEAN THE HOOK RACE.
CHANGE TO HIGH QUALITY
SEWING THREAD.
CLEAR OUT THE JUMMING
THREAD.
ADJUST BOBBIN THREAD
TENSION CORRECTLY.
P.8
5. NEEDLE
BREAKS
1. NEEDLE IS HITTING THE
NEEDLE PLATE.
2. NEEDLE IS BENT OR
WORN.
3. NEEDLE IS HITTING THE
HOOK RACE.
SEE MECHANICAL ADJUSTMENT
“NEEDLE DROP.”
CHANGE THE NEEDLE.
SEE MECHANICAL ADJUSTMENT
“CLEARANCE BETWEEN
NEEDLE AND HOOK”
P.11
P.13, P.14
2
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